bluuebunny/crossref_metadata_2025 huggingface dataset:
Ingestion and elemental budgets for Linuche unguiculata,
a scyphomedusa with zooxanthellae
Authors: Kremer Patricia
Published: June 2005

Specific rations for the zooxanthellae-bearing medusa, Linuche unguiculata, were calculated using two approaches: (a) gut contents of field collected medusae combined with experimental measurements of digestion time; and (b) experimental feeding studies combined with estimates of ambient prey biomass. Estimates of specific daily ration from gut contents averaged 5% for carbon, 6% for nitrogen, and 4% for phosphorus for the dominant size of medusae. Of the 868 medusae examined, 86% contained recognizable prey with an average of 3.6 items per medusa. Copepods dominated the gut contents (51%) as well as the ambient zooplankton prey (82%), but there was an over-representation of shelled prey, larval molluscs and foraminifera, in the gut (33%) compared with their availability (4%). Digestion times for crustaceans ranged from 1—4 h with longer times for larger prey. Ambient prey concentrations in areas of abundant L. unguiculata ranged from 0.2—4.0 prey l-1, with an average of 1.7 and no measurable day—night differences. There were also no measurable day—night differences in ingestion rates for field or laboratory fed medusae. Feeding studies showed a linear relationship between ingestion and prey concentration up to 400 prey l-1. Rations determined from experimental feeding studies were higher but less than double the ration estimates based on field gut contents. Specific ration decreased with increased medusa size in both field and laboratory results. Heterotrophy was calculated to be a major source of both nitrogen and phosphorus, but only a minor source of carbon. Elemental budgets for carbon, nitrogen and phosphorus were calculated using measured inputs of photosynthesis, ingestion, and dissolved nutrients and measured outputs of respiration, excretion, reproduction and tissue growth. Total measured outputs balanced the inputs, within the uncertainty associated with egg production.
The role of aerobic metabolism and intragel oxygen
in hypoxia tolerance of three ctenophores: Pleurobrachia bachei, Bolinopsis infundibulum and Mnemiopsis leidyi
Authors: Thuesen Erik V. , Rutherford Ladd D. , Brommer Patricia L.
Published: June 2005

Ctenophores are important members of planktonic communities that are often abundant in dysaerobic environments. Previous studies have shown that ctenophores are not adversely affected by extended periods of hypoxia. The three species used in this study, Pleurobrachia bachei, Bolinopsis infundibulum, and Mnemiopsis leidyi, were all able to oxyregulate to very low partial pressures of oxygen (PO2s). These species were found to have mean critical oxygen tensions of 7.7, 10.6, and 7.2 hPa respectively. In general, ctenophores are better oxyregulators than medusae and many species of shrimps, fish and squid. Intragel oxygen was measured using a fibre optic oxygen optode. All these ctenophores have intragel subsurface [O2]s of 5–10% below that of the surrounding seawater. Intragel oxygen measurements of P. bachei showed a gradient of decreasing PO2 from surface tissues to the gut. Specimens of P. bachei over 14 mm in diameter had anaerobic guts. Survival times in anoxia ranged from 0 h for M. leidyi to up to 6 h for P. bachei. Ctenophores rely on aerobic metabolism to tolerate hypoxia.
Gelatinous animals and physiology
Authors: Bone Quentin
Published: June 2005

This brief review discusses the different ways in which the study of gelatinous plankton has contributed to an understanding of the physiology and evolutionary relationships of other animals.
Ecological substrate in midwater: Doliolula equus,
a new mesopelagic tunicate
Authors: Robison Bruce H. , Raskoff Kevin A. , Sherlock Rob E.
Published: June 2005

In the pelagic habitat, the bodies of resident animals provide much of the ecological substrate available for other organisms to attach, find shelter, and seek food. In Monterey Bay, California, the doliolid Doliolula equus provides substrate for multiple symbionts. These include a mutualist hydroid, commensal ciliates, and a parasitic amphipod. This new doliolid is described based on in situ observations from a remotely operated vehicle, and from the laboratory examinations of 43 colonies comprising hundreds of living, individual blastozooids. Doliolula equus differs from other members of the suborder Doliopsidina in the shape of its body, the length and configuration of its third muscle band, the size of its buccal siphon, and the position of the spiral gland. The new doliolid was found principally at depths between 300 and 400 m. This species is bioluminescent, hermaphroditic, and about one zooid in ten is peppered with orange pigment spots. A variety of other, obviously related, yet undescribed forms has been observed in the eastern Pacific.
New mesopelagic larvaceans in the genus Fritillaria
from Monterey Bay, California
Authors: Hopcroft Russell R. , Robison Bruce H.
Published: June 2005

Three new species of Fritillaria are described from specimens collected by a remotely operated vehicle (ROV) between 180 and 735 m depth in Monterey Bay, California. Fritillaria rex becomes the largest species now described for this genus (trunk length up to 10 mm, tail length up to 18 mm). This species is characterized by five or six narrow muscle bundles on each side of the tail, slit-shaped spiracles, a spherical ovary and a cylindrical testis. Fritillaria amphigonadis (trunk length up to 5.2 mm, tail length up to 7.5 mm) is characterized by two narrow muscle bundles on each side of the tail, slit-shaped spiracles, paired spherical ovaries, and a unique pi-shaped testis. Fritillaria lucifer (trunk length up to 4.1 mm, tail length up to 7.0 mm) has 12 extremely thin muscle bundles distributed broadly across the tail, rounded spiracles, a spherical ovary and a U-shaped testis. An additional mesopelagic Fritillaria appears to be consistent with the description of the Mediterranean F. fage, but specific differences in pharyngeal cells, cellular patterns on the tail, and gonadal morphology suggest that the specimens from Monterey Bay are a new variety, F. fagei mbarii. Based on the relatively limited number of collections (i.e. only 20 specimens yielding four unique taxa), it would appear that the possible diversity of larvaceans that live below the surface mixed layer is significantly underestimated.
A re-examination of siphonophore terminology and morphology, applied to the description of two new prayine species
with remarkable bio-optical properties
Authors: Haddock Steven H.D. , Dunn Casey W. , Pugh Philip R.
Published: June 2005

Siphonophores (Cnidaria: Hydrozoa) are dominant members of the carnivorous plankton, and they are known for their ability to produce bioluminescence. Here we describe two new calycophoran species (sub-family Prayinae) that are unique in their morphological and optical traits. One species, Gymnopraia lapislazula gen. nov., sp. nov., displays a dramatic form of blue structural coloration, and the other, Lilyopsis fluoracantha, sp. nov., bears an exceptional amount of fluorescence–enough to give a greenish cast during white-light illumination. We also introduce a consistent terminology for siphonophore axes and zooids, discuss characters important for distinguishing the known prayine genera, and suggest that the presence or absence of a disjunct pedicular canal could be of diagnostic value for the group.
Renaissance taxonomy: integrative evolutionary analyses in the
classification of Scyphozoa
Authors: Dawson Michael N
Published: June 2005

New tools and techniques invigorate taxonomy through discovery and description of new organisms. New editions of the International Code on Zoological Nomenclature explicitly attempt to accommodate scientific advances, the problems they bring, and individual expertise in documenting the diversity of animal life. Yet, in practice, one of the most important biological and technical advances of the last quarter century—the democratization of large scale sequencing of DNA—remains at the fringe of metazoan taxonomy, where it keeps remarkable company with evolution. I discuss a more inclusive approach to taxonomy, primarily in the context of differentiating and describing species and subspecies of Scyphozoa. Global concern regarding biodiversity has rejuvenated efforts to discover and describe species; it may yet stimulate a renaissance if biological classification adopts a total evidence approach.
BOULEZ AT 80: THE PATH FROM THE NEW MUSIC
Authors: Whittall Arnold
Published: June 2005

In The Path to the New Music, Anton Webern's main purpose was to convince his audience that the twelve-note method was the natural outcome of an evolutionary process; that since ‘we compose as before’, the new was a reinterpretation of the old, not its rejection. Nothing could have been more soberly practical than the aspiration expressed in Webern's claim that ‘we want to say “in a quite new way” what has been said before’. By contrast, it has long been argued that the agenda of the post-1945 avant-garde, with Pierre Boulez a leading member, might be summarized thus: ‘we want to say, in as new a way as possible, what has not been said before’. Adorno based his 1955 critique of the new music around that ‘levelling and neutralization’ which, he believed, were the direct result of the technical obsessions of ‘total’ serialism: ‘the effort to rationalize music completely has something useless and frantic about it; it applies to a chaos that is no longer chaotic’. Adorno claimed that ‘what is needed is for expression to win back the density of experience, as was already tried during the expressionist period’. Composers should abandon this false form of the new music and begin to remember its earlier, more authentic manifestation.
A SIXTIES ‘PIERROT’: A PERSONAL MEMOIR
Authors: Manning Jane
Published: June 2005

The re-discovery and recent commercial release, on Regis/Forum, of one of my earliest performances of Schoenberg's Pierrot Lunaire, cannot help but evoke a mood of piquant personal reminiscence. The recording was made in 1967 at Olympic Studios in London, roughly two years after I first became acquainted with this riveting, endlessly compelling and many-layered masterpiece. The mid-1960s were marked by optimism, eager creative responses to the challenge of the new, and a spirit of idealism that is perhaps difficult to recapture in today's more commercially-driven world.
‘BARQUE D'OR’ — AN EARLY DUTILLEUX SONG REDISCOVERED
Authors: Obi-Keller Janet
Published: June 2005

It was with surprise and delight that, whilst on a research trip to Paris about a year ago, I accidentally discovered a score dating from Henri Dutilleux's Conservatoire period in the 1930s. What I stumbled upon was a song, titled Barque d'Or, written for soprano and piano. Dutilleux's father, Paul Dutilleux, who owned his own printing firm in Douai, published Barque d'Or in 1937. Roger Nichols has quoted Dutilleux's recollection of his father's work:

All that ties in too with the craftsmanship I witnessed in my father's workshop, especially at the bench of one old engraver. We had a great respect for him, he looked like Brahms. On Sundays it was at that bench that my father sat me down to do my harmony exercises, without the piano. During the week my ears were full of the rumbling of the machines, but at those moments the absolute silence seemed to me to have an extraordinary quality — it was a very unusual feeling, which I often think about, and it was a great encouragement to the formation of my inner ear.
George Benjamin on Nimbus
Authors: Venn Edward
Published: June 2005

BENJAMIN: Palimpsests; At First Light; Sudden Time; Olicantus. Ensemble Modern, Ensemble Modern Orchestra, c. George Benjamin, Oliver Knussen. Nimbus NI 5732.
New York, Carnegie Hall: Sallinen's Eighth Symphony
Authors: Stein Robert
Published: June 2005

Aulis Sallinen's symphonies are predictably always compared with those of his compatriot Sibelius. The Cincinnati SO's American première of his latest — the Eighth — in January, just nine months after its world première — Paavo Järvi conducted both performances — hardly made it easy for the listener to shake off such ancestral thoughts, as it was programmed alongside Sibelius's own Fifth. Whereas the Fifth is probably Sibelius's most joyous symphony, Sallinen's, despite initially envisaging an uplifting conclusion, eventually settles for the familiar darkness.
Petrassi's Concertos
Authors: Rickards Guy
Published: June 2005

PETRASSI: Concertos for Orchestra Nos. 1–8. Netherlands Radio Symphony Orchestra c. Arturo Tamayo. Stradivarius STR 33700 (2-CD set).
Dübendorf : Radulescu's ‘Cinerum’
Authors: Gilmore Bob
Published: June 2005

One of the consequences of the extreme paucity of new music broadcasting in Britain is that it is extraordinarily hard to keep up with the output of the major creative talents working in continental Europe. If we leave aside the already-canonical elder figures, only a handful of composers get anything like reasonable coverage (depending on one's definition of ‘reasonable’ — can one new work in four or five really be considered sufficient?). Others seem to have dropped out of listening range altogether. Such is the case with the Romanian-French composer Horatiu Radulescu, now 63 and by any standards one of the most fascinating and individual creative figures of his generation, whose music has been shamefully neglected by the BBC for more years than anyone would care to mention. Besides the usual sorts of prefabricated excuses why this is so (so many composers, so little available broadcast time), one speculates about further reasons. Is Radulescu's music considered simply too weird, too extreme, for Radio 3 listeners? Yes, his pieces are sometimes quite long; yes, they sometimes have strange titles (Capricorn's Nostalgic Crickets; Dizzy Divinity, I; Dr Kai Hong's Diamond Mountain); yes, they are sometimes not easy to digest at one listening. But isn't exposure to the cutting edge of the performing arts one of the things we should reasonably expect from our broadcasting media, especially in the case of a radical artist of such distinction and achievement?
London, Conway Hall and Jackson's Lane: Two Graham Williams premières
Authors: Anderson Martin
Published: June 2005

Graham Williams (Welsh-born, in 1940, but long since London-based) is almost as well known as a facilitator of music as a composer in his own right — a pity, because he has things to say which are worth listening to. My first, belated, encounter with his music came in the form of an Elegy for string octet, premièred by the Artea and Pavão Quartets in the Purcell Room in May 2003, a sober and dignified essay in controlled passion, stylistically somewhere between Alban Berg and the Strauss of Metamorphosen. It was the Artea Quartet which was responsible for my next encounter with Williams' music: they gave the première of his Fourth String Quartet in the Conway Hall, Red Lion Square, London, on 21 September 2004 — the three-minute, fourth-movement scherzo trailed four days beforehand in a live performance on In Tune on BBC Radio 3.
Boston: Milton Babbitt's ‘Concerti for Orchestra’
Authors: Lister Rodney
Published: June 2005

The difference that James Levine — finally installed and in control as Music Director — made almost instantly in the Boston Symphony is, to say the least, striking. The orchestra obviously loves working with him, and their contentment even spills over into the concerts when someone other than Levine is conducting; their playing these days is always uniformly wonderful, characterized not just by a concern for accuracy of detail and beauty of sound but also by a palpable pleasure in listening to each other and making music together. As well as changing the general atmosphere, Levine has altered the orientation of the BSO's programming drastically: the amount of 20th- and 21st-century music is greatly increased, but co-ordinated with older standard repertory works in interesting and appealing ways. Not only has the increased amount of newer music not hurt attendance, it seems to have increased interest — certainly among younger people and musicians, who are finding that there are things going on at Symphony Hall that they want to hear.
Vertical motions of the Puerto Rico Trench and Puerto Rico and their cause
Authors: ten Brink Uri
Published: June 2005

The Puerto Rico trench exhibits great water depth, an extremely low gravity anomaly, and a tilted carbonate platform between (reconstructed) elevations of +1300 m and −4000 m. I argue that these features are manifestations of large vertical movements of a segment of the Puerto Rico trench, its forearc, and the island of Puerto Rico that took place 3.3 m.y. ago over a time period as short as 14–40 kyr. I explain these vertical movements by a sudden increase in the slab's descent angle that caused the trench to subside and the island to rise. The increased dip could have been caused by shearing or even by a complete tear of the descending North American slab, although the exact nature of this deformation is unknown. The rapid (14–40 kyr) and uniform tilt along a 250 km long section of the trench is compatible with scales of mantle flow and plate bending. The proposed shear zone or tear is inferred from seismic, morphological, and gravity observations to start at the trench at 64.5°W and trend southwestwardly toward eastern Puerto Rico. The tensile stresses necessary to deform or tear the slab could have been generated by increased curvature of the trench following a counterclockwise rotation of the upper plate and by the subduction of a large seamount.
Barotropic tide and baroclinic waves observations in the Río de la Plata Estuary
Authors: Simionato C. G. , Meccia V. , Dragani W. , Nuñez M.
Published: June 2005

The first long‐period ADCP series collected in two locations of the salinity front of the Río de la Plata estuary are explored for periods less than 30 hours. Barotropic velocity shows tidal and mean currents consistent with what is known about the estuarine circulation in tidal and seasonal scales. Baroclinic currents provide the first evidence of the occurrence of internal waves, which can account for half of the total variance. In the northernmost location, predominantly zonal oscillations with semidiurnal period, and oscillations with a dominant meridional component and diurnal period, are found. Whereas the first ones can be related to the semidiurnal tide, the second ones seem to be atmospherically forced by the land/sea breeze. In the southernmost location, more rotational oscillations are observed, with periods around the inertial and diurnal ones. Inertial oscillations could result from wind relaxation, whereas diurnal oscillations also seem to be forced by breeze. Wave activity in the diurnal band was less frequent in the northernmost than in the southernmost location. This can be attributed to less frequent favorable stratification conditions in that area during the observed period. Wave activity in the southernmost location resulted weaker during the observed fall than during the summer. This could be a typical feature given that in autumn both the number of storms destroying the thermohaline structure increases and land/sea breeze is less frequent. This suggests a likely seasonal cycle in the diurnal wave activity in this area, given that those unfavorable conditions are even more marked during winter.
Crustal extension in the Ceraunius Fossae, Northern Tharsis Region, Mars
Authors: Borraccini F. , Lanci L. , Wezel F. C. , Baioni D.
Published: June 2005

We investigated the Ceraunius Fossae area, Northern Tharsis, in order to obtain quantitative information on the tectonic extension affecting this area. Tectonic structures of the Ceraunius Fossae area have been previously described using Viking images and interpreted as extensional structures. Laser altimetry data (MOLA) can be used to quantitatively investigate these structures with a better resolution. We developed a method to obtain E‐W oriented profiles (perpendicular to the main tectonic structures) with a sufficiently high resolution to analyze tectonic structures in spite of the low data density in this direction. We interpreted all the recognizable extensional structures along the profiles, and using a simplified structural model, we estimated tectonic extension along these transects. The extension calculated over the entire profiles is 36 km (e24 = (l1 − l0)/l0 = (910 km − 874 km)/874 km = 0.041) and 42 km (e26 = (730 km − 688 km)/688 km = 0.061) along profile 24 and profile 26, respectively. In the most deformed area, extension reaches the value of 22 km (emax = (l1 − l0)/l0 = (186 km − 164 km)/164 km = 0.134). Since the extension accounted by the topographic doming is negligible, a significant horizontal crustal motion is required to explain the observed extension.
Carbon monoxide distribution from the ACE‐FTS solar occultation measurements
Authors: Clerbaux C. , Coheur P.‐F. , Hurtmans D. , Barret B. , Carleer M. , Colin R. , Semeniuk K. , McConnell J. C. , Boone C. , Bernath P.
Published: June 2005

This paper presents a comprehensive analysis of the CO observations acquired during the first eight months (January to September 2004) of the ACE mission. We show that the ACE high‐resolution Fourier transform spectrometer (ACE‐FTS), which operates in the solar occultation geometry and covers a wide spectral interval in the infrared, provides useful measurements in both the CO 1‐0 and 2‐0 vibrational bands. Vertically‐resolved CO concentration profiles are retrieved, extending from the mid‐troposphere to the thermosphere (from about 5 to 110 km). We have analyzed the latitudinal variability of the measurements, from which various physical and chemical atmospheric processes are highlighted for further study.
Initial intercomparison of ozone and nitrogen dioxide number density profiles retrieved by the ACE‐FTS and GOMOS occultation experiments
Authors: Fussen D. , Vanhellemont F. , Dodion J. , Bingen C. , Walker K. A. , Boone C. D. , McLeod S. D. , Bernath P. F.
Published: June 2005

The ozone and nitrogen dioxide vertical number density profiles measured by the solar occultation Fourier transform spectrometer ACE‐FTS and the UV‐Vis stellar occultation instrument GOMOS are intercompared for 370 quasi‐coincident observations. A good agreement is found for ozone, mostly better than 10% between 15 and 45 km. Also, there is no evidence for a systematic altitude registration error in the ACE‐FTS profiles. A considerable ACE‐FTS negative bias (50–100%) is found however for the nitrogen dioxide data that cannot be explained by the use of a local photochemical model.
Differentiating airborne dust from cirrus clouds using MODIS data
Authors: Roskovensky J. K. , Liou K. N.
Published: June 2005

A method for detecting and differentiating dust from cirrus using satellite remote sensing has been developed. Using the differences in the reflective and emissive properties of each, it is shown that combining short‐wave reflectance ratio tests with long‐wave brightness temperature differences produce individual parameters that are able to specifically detect cirrus and dust. Through successive employment of both parameters, a method is established that separates dust from cirrus. Two case studies using Moderate resolution Imaging Spectroradiometer (MODIS) data are presented that show the effectiveness of the procedure.
What (and Why) is Positive Psychology?
Authors: Gable Shelly L. , Haidt Jonathan
Published: June 2005

Positive psychology is the study of the conditions and processes that contribute to the flourishing or optimal functioning of people, groups, and institutions. In this brief introduction, the authors give examples of current work in positive psychology and try to explain why the positive psychology movement has grown so quickly in just 5 years. They suggest that it filled a need: It guided researchers to understudied phenomena. The authors close by addressing some criticisms and shortcomings of positive psychology, such as the relative lack of progress in studying positive institutions.
Pursuing Happiness: The Architecture of Sustainable Change
Authors: Lyubomirsky Sonja , Sheldon Kennon M. , Schkade David
Published: June 2005

The pursuit of happiness is an important goal for many people. However, surprisingly little scientific research has focused on the question of how happiness can be increased and then sustained, probably because of pessimism engendered by the concepts of genetic determinism and hedonic adaptation. Nevertheless, emerging sources of optimism exist regarding the possibility of permanent increases in happiness. Drawing on the past well-being literature, the authors propose that a person's chronic happiness level is governed by 3 major factors: a genetically determined set point for happiness, happiness-relevant circumstantial factors, and happiness-relevant activities and practices. The authors then consider adaptation and dynamic processes to show why the activity category offers the best opportunities for sustainably increasing happiness. Finally, existing research is discussed in support of the model, including 2 preliminary happiness-increasing interventions.
Sociality, Spirituality, and Meaning Making: Chicago Health, Aging, and Social Relations Study
Authors: Cacioppo John T. , Hawkley Louise C. , Rickett Edith M. , Masi Christopher M.
Published: June 2005

Scientific theories in the natural sciences posit invisible forces operating with measurable effects on physical bodies, but the scientific study of invisible forces acting on human bodies has made limited progress. The topics of sociality, spirituality, and meaning making are cases in point. The authors discuss some of the possible reasons for this as well as contemporary developments in the social sciences and neurosciences that may make such study possible and productive.
Positive Psychology at the Summit
Authors: Simonton Dean Keith , Baumeister Roy F.
Published: June 2005

Psychology has traditionally placed more emphasis on the negative than positive aspects of human behavior. The positive psychology movement, since its beginnings in 1999, has made major advances toward correcting this imbalance. Research inspired by the movement now spans an impressive range of topics, including many that are absolutely essential to a comprehensive psychological understanding of human nature. The present special issue provides a sampling of some of the best work in the area. All but the first and last articles come from presentations at the Second International Positive Psychology Summit, held in 2003 in Washington, DC. This sample can be supplemented by the chapters that have appeared in several recent anthologies of contemporary research.
N-terminal cleavage of proTGFα occurs at the cell surface by a TACE-independent activity
Authors: JUANES Pedro P. , FERREIRA Laura , MONTERO Juan Carlos , ARRIBAS Joaquín , PANDIELLA Atanasio
Published: June 2005

ProTGFα (transforming growth factor α precursor) maturation and conversion into soluble TGFα is a complex process that involves three proteolytic steps. One, that occurs co-translationally, eliminates the signal sequence. Another, occurring at the juxtamembrane domain, solubilizes TGFα. A third cleavage removes the N-terminal extension of proTGFα. This latter step has been poorly studied, mainly because of the rapid kinetics of this cleavage. In the present study, we have designed a strategy to analyse several aspects regarding this N-terminal cleavage. In vivo treatment with the hydroxamate-based metalloprotease inhibitors BB3103 or TAPI-2 (tumour necrosis factor-α protease inhibitor 2) reversibly induced accumulation of forms of proTGFα that included the N-terminal extension. N-terminal shedding was rapid, and occurred at the cell surface. However, the machinery responsible for the N-terminal cleavage was inactive in other cellular sites, such as the endoplasmic reticulum. Experiments of proTGFα expression and maturation in cells deficient in TACE (tumour-necrosis-factor-α-converting enzyme) activity indicated that this protease was dispensable for N-terminal processing of proTGFα in vivo, but was required for regulated cleavage at the C-terminus. These findings indicate that TACE is not involved in N-terminal processing of proTGFα, and suggest differences in the machineries that control the cleavage at both ends of TGFα within its precursor.
Molecular cloning and characterization of a novel phospholipase C, PLC-η
Authors: HWANG Jong-Ik , OH Yong-Seok , SHIN Kum-Joo , KIM Hyun , RYU Sung Ho , SUH Pann-Ghill
Published: June 2005

PLC (phospholipase C) plays an important role in intracellular signal transduction by hydrolysing phosphatidylinositol 4,5-bisphosphate, a membrane phospholipid. To date, 12 members of the mammalian PLC isoforms have been identified and classified into five isotypes β, γ, δ, ε and ζ, which are regulated by distinct mechanisms. In the present study, we describe the identification of a novel PLC isoform in the brains of human and mouse, named PLC-η, which contains the conserved pleckstrin homology domain, X and Y domains for catalytic activity and the C2 domain. The first identified gene encoded 1002 (human) or 1003 (mouse) amino acids with an estimated molecular mass of 115 kDa. The purified recombinant PLC-η exhibited Ca2+-dependent catalytic activity on phosphatidylinositol 4,5-bisphosphate. Furthermore, molecular biological analysis revealed that the PLC-η gene was transcribed to several splicing variants. Although some transcripts were detected in most of the tissues we examined, the transcript encoding 115 kDa was restricted to the brain and lung. In addition, the expression of the 115 kDa protein was defined in only nerve tissues such as the brain and spinal cord. In situ hybridization analysis with brain revealed that PLC-η was abundantly expressed in various regions including cerebral cortex, hippocampus, zona incerta and cerebellar Purkinje cell layer, which are neuronal cell-enriched regions. These results suggest that PLC-η may perform fundamental roles in the brain.
Oxidation of hypotaurine and cysteine sulphinic acid by peroxynitrite
Authors: FONTANA Mario , AMENDOLA Donatella , ORSINI Emanuela , BOFFI Alberto , PECCI Laura
Published: June 2005

Peroxynitrite mediates the oxidation of the sulphinic group of both HTAU (hypotaurine) and CSA (cysteine sulphinic acid), producing the respective sulphonates, TAU (taurine) and CA (cysteic acid). The reaction is associated with extensive oxygen uptake, suggesting that HTAU and CSA are oxidized by the one-electron transfer mechanism to sulphonyl radicals, which may initiate an oxygen-dependent radical chain reaction with the sulphonates as final products. Besides the one-electron mechanism, HTAU and CSA can be oxidized by the two-electron pathway, leading directly to sulphonate formation without oxygen consumption. The apparent second-order rate constants for the direct reaction of peroxynitrite with HTAU and CSA at pH 7.4 and 25 °C are 77.4±5 and 76.4±9 M−1·s−1 respectively. For both sulphinates, the apparent second-order rate constants increase sharply with decrease in pH, and the sigmoidal curves obtained are consistent with peroxynitrous acid as the species responsible for sulphinate oxidation. The kinetic data, together with changes in oxygen uptake, sulphinate depletion, sulphonate production, and product distribution of nitrite and nitrate, suggest that oxidation of sulphinates by peroxynitrite may take place by the two reaction pathways whose relative importance depends on reagent concentrations and pH value. In the presence of bicarbonate, the direct reaction of sulphinates with peroxynitrite is inhibited and the oxidative reaction probably involves only the radicals •NO2 and CO3•−, generated by decomposition of the peroxynitrite-CO2 adduct.
Mammalian cells stably overexpressing N-acylphosphatidylethanolamine-hydrolysing phospholipase D exhibit significantly decreased levels of N-acylphosphatidylethanolamines
Authors: OKAMOTO Yasuo , MORISHITA Jun , WANG Jun , SCHMID Patricia C. , KREBSBACH Randy J. , SCHMID Harald H. O. , UEDA Natsuo
Published: June 2005

In animal tissues, NAEs (N-acylethanolamines), including N-arachidonoylethanolamine (anandamide), are primarily formed from their corresponding NAPEs (N-acylphosphatidylethanolamines) by a phosphodiesterase of the PLD (phospholipase D) type (NAPE-PLD). Recently, we cloned cDNAs of NAPE-PLD from mouse, rat and human [Okamoto, Morishita, Tsuboi, Tonai and Ueda (2004) J. Biol. Chem. 279, 5298–5305]. However, it remained unclear whether NAPE-PLD acts on endogenous NAPEs contained in the membrane of living cells. To address this question, we stably transfected two mammalian cell lines (HEK-293 and CHO-K1) with mouse NAPE-PLD cDNA, and investigated the endogenous levels and compositions of NAPEs and NAEs in these cells, compared with mock-transfected cells, with the aid of GC-MS. The overexpression of NAPE-PLD caused a decrease in the total amount of NAPEs by 50–90% with a 1.5-fold increase in the total amount of NAEs, suggesting that the recombinant NAPE-PLD utilizes endogenous NAPE as a substrate in the cell. Since the compositions of NAEs and NAPEs of NAPE-PLD-overexpressing cells and mock-transfected cells were very similar, the enzyme did not appear to discriminate among the N-acyl groups of endogenous NAPEs. These results confirm that overexpressed NAPE-PLD is capable of forming NAEs, including anandamide, in living cells.
An abortive apoptotic pathway induced by singlet oxygen is due to the suppression of caspase activation
Authors: OTSU Kaoru , SATO Kazuaki , IKEDA Yoshitaka , IMAI Hirotaka , NAKAGAWA Yasuhito , OHBA Yoshihiro , FUJII Junichi
Published: June 2005

Singlet oxygen causes the cytotoxic process of tumour cells in photodynamic therapy. The mechanism by which singlet oxygen damages cells is, however, not fully understood. To address this issue, we synthesized and used two types of endoperoxides, MNPE (1-methylnaphthalene-4-propionate endoperoxide) and NDPE (naphthalene-1,4-dipropionate endoperoxide), that generate defined amounts of singlet oxygen at 37 °C with similar half lives. MNPE, which is more hydrophobic than NDPE, induced the release of cytochrome c from mitochondria into the cytosol and exhibited cytotoxicity, but NDPE did not. RBL cells, a rat basophil leukaemia-derived line, that overexpress phospholipid hydroperoxide glutathione peroxidase in mitochondria were found to be highly resistant to the cytotoxic effect of MNPE. MNPE treatment induced much less DNA ladder formation and nuclear fragmentation in cells than etoposide treatment, even though these treatments induced a similar extent of cellular damage. Singlet oxygen inhibited caspase 9 and 3 activities directly and also suppressed the activation of the caspase cascade. Collectively, these data suggest that singlet oxygen triggers an apoptotic pathway by releasing cytochrome c from mitochondria via the peroxidation of mitochondrial components and results in cell death that is different from typical apoptosis, because of the abortive apoptotic pathway caused by impaired caspase activation.
Rab coupling protein is selectively degraded by calpain in a Ca2+-dependent manner
Authors: MARIE Nicolas , LINDSAY Andrew J. , McCAFFREY Mary W.
Published: June 2005

RCP (Rab coupling protein) belongs to the recently identified Rab11-FIPs (Rab11 family of interacting proteins). All the Rab-FIP members have the ability to bind Rab11 tightly via a Rab-binding domain located near their C-termini. RCP belongs to the class I Rab11-FIP subfamily, characterized by the presence of a conserved C2 domain near its N-terminus. The function of this protein in Rab11-dependent membrane trafficking remains to be fully understood. In the present study, we have identified three putative PEST (Pro, Glu, Ser/Thr-rich) sequences in RCP. PEST motifs play a role in targeting a protein for proteolytic degradation. We have demonstrated that RCP undergoes calcium-dependent degradation which can be prevented by specific calpain inhibitors. Using a mutant, lacking the three PEST sequences, RCPΔPEST, we demonstrated that they are necessary for the cleavage of RCP by calpains. When expressed in A431 cells, RCPΔPEST displays significantly greater localization to the plasma membrane, compared with the wild-type protein. Similarly, treatment with the calpain inhibitor, calpeptin, results in the redistribution of endogenous RCP to the periphery of the cell. We propose that once the Rab11/RCP-regulated cargo has been delivered from the endocytic recycling compartment to the plasma membrane, RCP is inactivated by calpain-mediated proteolysis.
Fibroblast growth factors share binding sites in heparan sulphate
Authors: KREUGER Johan , JEMTH Per , SANDERS-LINDBERG Emil , ELIAHU Liat , RON Dina , BASILICO Claudio , SALMIVIRTA Markku , LINDAHL Ulf
Published: June 2005

HS (heparan sulphate) proteoglycans bind secreted signalling proteins, including FGFs (fibroblast growth factors) through their HS side chains. Such chains contain a wealth of differentially sulphated saccharide epitopes. Whereas specific HS structures are commonly believed to modulate FGF-binding and activity, selective binding of defined HS epitopes to FGFs has generally not been demonstrated. In the present paper, we have identified a series of sulphated HS octasaccharide epitopes, derived from authentic HS or from biosynthetic libraries that bind with graded affinities to FGF4, FGF7 and FGF8b. These HS species, along with previously identified oligosaccharides that interact with FGF1 and FGF2, constitute the first comprehensive survey of FGF-binding HS epitopes based on carbohydrate sequence analysis. Unexpectedly, our results demonstrate that selective modulation of FGF activity cannot be explained in terms of binding of individual FGFs to specific HS target epitopes. Instead, different FGFs bind to identical HS epitopes with similar relative affinities and low selectivity, such that the strength of these interactions increases with increasing saccharide charge density. We conclude that FGFs show extensive sharing of binding sites in HS. This conclusion challenges the current notion of specificity in HS–FGF interactions, and instead suggests that a set of common HS motifs mediates cellular targeting of different FGFs.
Gene duplication, gene loss and evolution of expression domains in the vertebrate nuclear receptor NR5A (Ftz-F1) family
Authors: KUO Ming-Wei , POSTLETHWAIT John , LEE Wen-Chih , LOU Show-Wan , CHAN Woon-Khiong , CHUNG Bon-chu
Published: June 2005

Fushi tarazu factor 1 (Ftz-F1, NR5A) is a zinc-finger transcription factor that belongs to the nuclear receptor superfamily and regulates genes that are involved in sterol and steroid metabolism in gonads, adrenals, liver and other tissues. To understand the evolutionary origins and developmental genetic relationships of the Ftz-F1 genes, we have cloned four homologous Ftz-f1 genes in zebrafish, called ff1a, ff1b, ff1c and ff1d. These four genes have different temporal and spatial expression patterns during development, indicating that they have distinct mechanisms of genetic regulation. Among them, the ff1a expression pattern is similar to mammalian Nr5a2, while the ff1b pattern is similar to that of mammalian Nr5a1. Genetic mapping experiments show that these four ff1 genes are located on chromosome segments conserved between the zebrafish and human genomes, indicating a common ancestral origin. Phylogenetic and conserved synteny analysis show that ff1a is the orthologue of NR5A2, and that ff1b and ff1d genes are co-orthologues of NR5A1 that arose by a gene-duplication event, probably a whole-genome duplication, in the ray-fin lineage, and each gene is located next to an NR6A1 co-orthologue as in humans, showing that the tandem duplication occurred before the divergence of human and zebrafish lineages. ff1c does not have a mammalian counterpart. Thus we have characterized the phylogenetic relationships, expression patterns and chromosomal locations of these Ftz-F1 genes, and have demonstrated their identities as NR5A genes in relation to the orthologous genes in other species.
Activation of A431 human carcinoma cell motility by extracellular high-mobility group box 1 protein and epidermal growth factor stimuli
Authors: SPARATORE Bianca , PATRONE Mauro , PASSALACQUA Mario , PEDRAZZI Marco , LEDDA Sabina , PONTREMOLI Sandro , MELLONI Edon
Published: June 2005

HMGB1 (high-mobility group box 1) protein, a pleiotropic cytokine released by several cell types under physiological and pathological conditions, has been identified as a signal molecule active on A431 cells. Although extracellular HMGB1 itself does not trigger any detectable signalling effect on these cells, it induces an increased susceptibility to EGF (epidermal growth factor) stimulation. Specifically, at concentrations of EGF which promote undetectable or limited cell responses, the addition of sub-nanomolar concentrations of HMGB1 potentiates the effect of EGF by specifically activating a downstream pathway that leads to enhanced cell motility through an increase in Ca2+ influx, activation of extracellular-signal-regulated kinase 1/2 and remodelling of the actin cytoskeleton. These results, which identify extracellular HMGB1 as an activator of human tumour cell migration operating in concert with EGF, have important implications in the search for novel strategies to control tumour progression and metastatic invasion.
Phospholipase D activity is essential for actin localization and actin-based motility in Dictyostelium
Authors: ZOUWAIL Soha , PETTITT Trevor R. , DOVE Stephen K. , CHIBALINA Margarita V. , POWNER Dale J. , HAYNES Lee , WAKELAM Michael J. O. , INSALL Robert H.
Published: June 2005

PLD (phospholipase D) activity catalyses the generation of the lipid messenger phosphatidic acid, which has been implicated in a number of cellular processes, particularly the regulation of membrane traffic. In the present study, we report that disruption of PLD signalling causes unexpectedly profound effects on the actin-based motility of Dictyostelium. Cells in which PLD activity is inhibited by butan-1-ol show a complete loss of actin-based structures, accompanied by relocalization of F-actin into small clusters, and eventually the nucleus, without a visible fall in levels of F-actin. Addition of exogenous phosphatidic acid reverses the effects of butan-1-ol, confirming that these effects are caused by inhibition of PLD. Loss of motility correlates with complete inhibition of endocytosis and a reduction in phagocytosis. Inhibition of PLD caused a major decrease in the synthesis of PtdIns(4,5)P2, which could again be reversed by exogenously applied phosphatidic acid. Thus the essential role of PLD signalling in both motility and endocytosis appears to be mediated directly via regulation of PtdIns(4)P kinase activity. This implies that localized PLD-regulated synthesis of PtdIns(4,5)P2 is essential for Dictyostelium actin function.
Bacteriophage-encoded glucosyltransferase GtrII of Shigella flexneri: membrane topology and identification of critical residues
Authors: LEHANE Adele M. , KORRES Haralambos , VERMA Naresh K.
Published: June 2005

The Shigella flexneri serotypes differ in the nature of their O-antigens. The addition of glucosyl or O-acetyl groups to the common backbone repeat units gives rise to the different serotypes. GtrII glucosylates rhamnose III of the O-antigen repeat unit, thus converting serotype Y (which has no modifications to the basic O-antigen repeat unit) into serotype 2a, the most prevalent serotype. In the present study, the topology of GtrII has been determined. GtrII has nine transmembrane helices, a re-entrant loop and three large periplasmic regions. Four critical residues (Glu40, Phe414, Cys435 and Lys478) were identified in two of the periplasmic regions. Despite the lack of sequence similarity between GtrII and the Gtrs from other serotypes, three of the critical residues identified are conserved in the remaining Gtrs. This is consistent with some degree of mechanistic conservation in this functionally related group of proteins.
Identification and functional characterization of a novel Candida albicans gene CaMNN5 that suppresses the iron-dependent growth defect of Saccharomyces cerevisiae aft1Δ mutant
Authors: BAI Chen , CHAN Fong Yee , WANG Yue
Published: June 2005

In Saccharomyces cerevisiae, the transcription factor Aft1p plays a central role in regulating many genes involved in iron acquisition and utilization. An aft1Δ mutant exhibits severely retarded growth under iron starvation. To identify the functional counterpart of AFT1 in Candida albicans, we transformed a C. albicans genomic DNA library into aft1Δ to isolate genes that could allow the mutant to grow under iron-limiting conditions. In the present paper, we describe the unexpected discovery in this screen of CaMNN5. CaMnn5p is an α-1,2-mannosyltransferease, but its growth-promoting function in iron-limiting conditions does not require this enzymatic activity. Its function is also independent of the high-affinity iron transport systems that are mediated by Ftr1p and Fth1p. We obtained evidence suggesting that CaMnn5p may function along the endocytic pathway, because it cannot promote the growth of end4Δ and vps4Δ mutants, where the endocytic pathway is blocked at an early and late step respectively. Neither can it promote the growth of a fth1Δ smf3Δ mutant, where the vacuole–cytosol iron transport is blocked. Expression of CaMNN5 in S. cerevisiae specifically enhances an endocytosis-dependent mechanism of iron uptake without increasing the uptake of Lucifer Yellow, a marker for fluid-phase endocytosis. CaMnn5p contains three putative Lys-Glu-Xaa-Xaa-Glu iron-binding sites and co-immunoprecipitates with 55Fe. We propose that CaMnn5p promotes iron uptake and usage along the endocytosis pathway under iron-limiting conditions, a novel function that might have evolved in C. albicans.
The phosphorylation of CapZ-interacting protein (CapZIP) by stress-activated protein kinases triggers its dissociation from CapZ
Authors: EYERS Claire E. , McNEILL Helen , KNEBEL Axel , MORRICE Nick , ARTHUR Simon J. C. , CUENDA Ana , COHEN Philip
Published: June 2005

A protein expressed in immune cells and muscle was detected in muscle extracts as a substrate for several SAPKs (stress-activated protein kinases). It interacted specifically with the F-actin capping protein CapZ in splenocytes, and was therefore termed ‘CapZIP’ (CapZ-interacting protein). Human CapZIP was phosphorylated at Ser-179 and Ser-244 by MAPKAP-K2 (mitogen-activated protein kinase-activated protein kinase 2) or MAPKAP-K3 in vitro. Anisomycin induced the phosphorylation of CapZIP at Ser-179 in Jurkat cells, which was prevented by SB 203580, consistent with phosphorylation by MAPKAP-K2 and/or MAPKAP-K3. However, osmotic shock-induced phosphorylation of Ser-179 was unaffected by SB 203580. These and other results suggest that CapZIP is phosphorylated at Ser-179 in cells by MAPKAP-K2/MAPKAP-K3, and at least one other protein kinase. Stress-activated MAP kinase family members phosphorylated human CapZIP at many sites, including Ser-68, Ser-83, Ser-108 and Ser-216. Ser-108 became phosphorylated when Jurkat cells were exposed to osmotic shock, which was unaffected by SB 203580 and/or PD 184352, or in splenocytes from mice that do not express either SAPK3/p38γ or SAPK4/p38δ. Our results suggest that CapZIP may be phosphorylated by JNK (c-Jun N-terminal kinase), which phosphorylates CapZIP to >5 mol/mol within minutes in vitro. Osmotic shock or anisomycin triggered the dissociation of CapZIP from CapZ in Jurkat cells, suggesting that phosphorylation of CapZIP may regulate the ability of CapZ to remodel actin filament assembly in vivo.