bluuebunny/crossref_metadata_2025_split huggingface dataset:
Porcine brain neurofilament‐H tail domain kinase: Its identification as cdk5/p26 complex and comparison with cdc2/cyclin B kinase
Authors: Hisanaga Shin‐Ichi , Uchiyama Massashi , Hosoi Tomoko , Yamada Keisuke , Honma Naoyuki , Ishiguro Koichi , Uchida Tsuneko , Dahl Doris , Ohsumi Keita , Kishimoto Takeo 
Published: February 2005

AbstractUsing dephosphorylated neurofilament (NF) proteins as substrates, the kinase with a higher activity for in the dephosphorylated NF‐H than the phosphorylated form of NF‐H was searched for in the porcine brain extract. Most NF‐H kinase activity in the brain extract pelleted with microtubules. The NF‐H kinase purified from a high salt extract of the microtubule pellets was composed of cdk5 and a 26 kDa protein, a fragment of the 35 kDa regulatory subunit of cdk5. In contrast to the association of the active kinase with microtubules, each of uncomplexed cdk5 and the 35 kDa regulatory subunit was differently distributed in the supernatant fraction and the pellet, respectively, by ultracentrifugation of the brain extract. Dephosphorylated forms of NF‐H and NF‐M became reactive to antibodies recoginizing in vivo phosphorylation sites (SM131, 34, and 36, JJ31 and 51) by phosphorylation with cdk5/p26. cdk5/p26 showed similar enzymatic properties to p34cdc2/cyclin B kinase; the substrate specificity and inhibition by a p34cdc2 kinase specific inhibitor, butyrolactone I. However, p34cdc2/cyclin B kinase was distinguished from cdk5/p26 by its binding to p13suc1 protein and by its reactivity to anti‐p34cdc2 antibodies. In spite of similar enzymatic properties of cdk5/p26 and p34cdc2/cyclin B kinase, cdk5/26 did not display M‐phase promoting activity when assayed with a cell‐free system of Xenopus egg extract. © 1995 Wiley‐Liss, Inc.
Cytoskeleton of the Drosophila egg chamber: New observations on microfilament distribution during oocyte growth
Authors: Riparbelli Maria Giovanna , Callaini Giuliano 
Published: February 2005

AbstractThe distribution of microfilaments in Drosophila egg chambers stained with rhodamine (Rh)‐conjugated phallcidin was studied by laser scanning confocal microscopy and transmission electron microscopy. These techniques revealed new details in the pattern of microfilament localization. We observed in stage 1–3 egg chambers accumulation of filamentous actin in the oocyte cytoplasm between the ring canals connecting the oocyte with adjacent nurse cells. Starting from stages 6–7 short microfilament bundles arranged in basket‐like structures were associated with the side of the ring canals facing the nurse cell cytoplasm. We also observed a dramatic decrease in the actin network associated with the cortex of the oocyte in stage 10. During stage 10B the nurse cell cytoplasm was crossed by radial actin bundles that showed a sarcomeric‐like cross striation after Rh‐phalloidin staining. The ring canals also did not uniformly stain but showed a punctate labeling. The implications of the actin cytoskeleton during oocyte growth are discussed. © 1995 Wiley‐Liss, Inc.
Structural and biological consequences of increased vimentin expression in simple epithelial cell types
Authors: Andreoli Jeanne M. , Trevor Katrina T. 
Published: February 2005

AbstractCytoskeletal intermediate filaments (IFs) constitute a diverse family of proteins whose members are expressed in tissue‐specific patterns. Although vimentin IFs are normally restricted to mesenchyme, a variety of cell types express vimentin alone or together with cell‐specific IFs during growth, differentiation, and neoplasia. In this study, we have investigated the influence of increased vimentin expression on the simple epithelial cell phenotype. An expression vector encoding a human vimentin cDNA was transfected into the murine HR9 endoderm and F9 embryonal carcinoma cell lines, which serve as models for early extraembryonic epithelial differentiation. Stable clones that expressed varying levels of the human vimentin were characterized by immunofluorescence and biochemical analysis. A relatively high level of vimentin expression in HR9 and differentiated F9 epithelial cells resulted in aberrant vimentin structures with a co‐collapss of keratin K8/K18 filaments and lowered amounts of keratin protein. In F9 epithelial cells, the desmosomal proteins DP I/II did not appear to localize to cell surface desmosomes but rather co‐aggregated with the perturbed IFs. Although overall cell morphology was not dramatically altered, individual nuclei were distorted by excess intracellular vimentin. Furthermore, cell proliferation as well as the cell spreading response time were slowed. There appears to be a threshold effect regarding overall vimentin levels as cells that expressed lower amounts of the human vimentin exhibited no obvious structural nor biological effects. Our results demonstrate that wild‐type vimentin can act as a “mutant” protein when present at high intracellular levels, inducing a variety of phenotypic changes. © 1995 Wiley‐Liss, Inc.
Genomic structure of a cytoplasmic dynein heavy chain gene from the nematode Caenorhabditis elegans
Authors: Lye R. John , Wilson Richard K. , Waterston Robert H. 
Published: February 2005

AbstractWe report the cloning and sequencing of genomic DNA encoding a cytoplasmic dynein heavy chain from the nematode Caenorhabditis elegans. In a contiguous stretch of 35,103 bp of DNA from the left arm of linkage group I, we have found a gene that is predicted to encode a protein of 4,568 amino acids. This gene is composed of 15 exons and 14 relatively short introns, and it has significant homology of the other dynein heavy chains in the databases. The deduced molecular mass of the derived polypeptide is 512,624 Da. As with other dynein heavy chains that have been sequenced to date, it contains four GXXGXGK(S/T) motifs that form part of the consensus sequence for nucleotide triphosphate‐binding domains. Comparison of axonemal and cytoplasmic dynein heavy chains shows that regions of homology among all dyneins are clustered in the carboxyl terminal two‐thirds of the polypeptide, whereas the amino terminal one‐third of the heavy chains may contain domains that specify functions that differ between axonemal and cytoplasmic forms of the dynein heavy chain. © 1995 Wiley‐Liss, Inc.
Multiple protein kinase activities required for activation of sperm flagellar motility
Authors: Chaudhry Prem S. , Creagh Susan , Yu Nam , Brokaw Charles J. 
Published: February 2005

AbstractA specific peptide inhibitor of the cyclic AMP (cAMP)‐dependent protein kinase (PKI‐peptide) is a very effective inhibitor of the cAMP‐dependent activation of motility of Ciona spermatozoa, when the PKI‐peptide is present at the beginning of incubation of demembranated spermatozoa with cAMP and ATP. Under conditions where approximately 120 sec is required for full activation of motility, the window of sensitivity to the PKI‐peptide lasts for only 25–30 sec. Examination of sperm pellet proteins labeled with 32P ATP during activation reveals a major 25 kDa phosphoprotein and 2 minor phosphoproteins whose phosphorylation is highly sensitive to inhibition by the PKI‐peptide and essentially complete during this early phase. These sperm proteins appear to be immediate substrates for cAMP‐dependent protein kinase, and phosphorylation of one or more of these appears to be required, but not sufficient, for activation of motility. The phosphorylation of other proteins is reduced or eliminated when PKI‐peptide is present at the beginning of incubation, but is unaffected by later addition of PKI‐peptide. Some of these substrates appear to be likely candidates for axonemal proteins that must be phosphorylated during the later stages of incubation in order to complete the activation process. This selection is based upon a high degree of inhibition by inclusion of PKI‐peptide or other inhibitors at the start of the incubation process, on near‐completion of their phosphorylation by the end of the 2 min incubation period required for activation of motility, and evidence that these proteins are phosphorylated during in vivo activation of motility. Although these observations suggest the presence of a second kinase activity that is upregulated by the initial activation of the cAMP‐dependent protein kinase, assays using exogenous substrates have not yet been able to identify such a kinase activity. © 1995 Wiley‐Liss, Inc.
Exploring the function of inner and outer dynein arms with Chlamydomonas mutants
Authors: Kamiya Ritsu 
Published: February 2005

AbstractChlamydomonas flagella contain as many as 11 different dynein heavy chains, three in the outer arm and eight in the inner. Several lines of evidence suggest that these different dyneins are functionally diverse. This diversity may be important for the generation of axonemal undulating movement.
Regulation of dynein‐driven microtubule sliding by an axonemal kinase and phosphatase in Chlamydomonas flagella
Authors: Habermacher Geoffrey , Sale Winfield S. 
Published: February 2005

AbstractThe following is a summary of physiological and pharmacological studies of the regulation of dynein‐driven microtubule sliding in Chlamydomonas flagella. The experimental basis for the study is described, and data indicating that an axonemal cAMP‐dependent protein kinase can regulate inner arm dynein activity are reviewed. In addition, preliminary data are summarized indicating that an axonemal type 1 phosphatase can also regulate dynein‐drive microtubule sliding velocity. It is predicted that the protein kinase, phosphatase, and an inner dynein arm component form a regulatory complex in the axoneme.
Biophysical aspects and modelling of ciliary motility
Authors: Holwill M. E. J. , Foster G. F. , Hamasaki T. , Satir P. 
Published: February 2005

AbstractThe dominance of viscous forces in the generation of propulsive thrust by cilia is emphasised. Fourier analysis indicates that ciliary bends consist of circular arcs joined by linear segments; this arc‐line shape appears to be a property associated with the molecular mechanism responsible for bending the cilium and is unchanged by variations in the external viscous loading on the organelle. The flexibility of a computer‐generated model of axonemal structure is demonstrated by the incorporation of recent data concerning the surface lattice of the microtubules. Computer simulations using the model show that predictions based on stochastic, rather than co‐ordinated, dynein arm activity provide a qualitative match to experimental observations of microtubules gliding over fields of dynein molecules.
Functional dissection of the dynein motor domain
Authors: Eshel Dan 
Published: February 2005

AbstractThe highly conserved lysine residue in the putative hydrolytic ATP‐binding motif of the yeast cytoplasmic dynein heavy chain was replaced with leucine. The mutation was generated by a two‐stage transformation method designed for genomic site‐directed mutagenesis. Preliminary observations show that the effects of this alteration on the cellular roles of dynein are indistinguishable from those of a disruption mutation in which the entire motor domain is not expressed. © 1995 Wiley‐Liss, Inc.
Recombinant expression of the brush border myosin I heavy chain
Authors: Collins Kathleen , Matsudaira Paul T. 
Published: February 2005

AbstractAlthough the specific functions of myosin I motors are not known, their localization to membrane structures suggests a function in membrane motility. Different myosin I isoforms in the same cell or in different cells can possess different localizations. To determine if the localization and biochemical activity of the best‐characterized mammalian myosin I, chicken intestinal epithelium brush border myosin I, was dependent on determinants of the membrane or actin cytoskeleton specific to epithelial cells, we transfected the cDNA for the heavy chain of this myosin into COS cells. Transient transfection of COS cells with the chicken brush border myosin I heavy chain resulted in the production of recombinant myosin I. Recombinant brush border myosin I localized to protrusions of the plasma membrane, particularly at spreading cell edges, and also to unknown cytoplasmic structures. Some cells expressing particularly high levels of brush border myosin I possessed a highly irregular surface. Recombinant brush border myosin I purified from COS cells bound to actin filaments in an ATP‐dependent manner and decorated actin filaments to form a characteristic appearance. The recombinant myosin also catalyzed calcium‐sensitive, actin‐activated MgATPase activity similar to that of the native enzyme. Thus, any cellular factor required for the general membrane localization or biochemical activity of brush border myosin I is present in COS cells as well as intestinal epithelium.
Centripetal transport of microtubules in motile cells
Authors: Mikhailov Alexei V. , Gundersen Gregg G. 
Published: February 2005

AbstractThe Study of microtubule (MT) dynamics in cells has largely been restricted to events occurring over relatively short periods in nonmotile or stationary cell in culture. By using the antioxidant, Oxyrase, we have reduced the sensitivity of fluorescent MTs to photodamage and this has allowed us to image fluorescent MTs with good temporal resolution over much longer periods of time. We have used our enhanced imaging capabilities to examine MT dynamics in fibroblasts moving directionally into a wound. We found that MTs in these cells exhibited dynamic instability similar to that reported for other cells. More interestingly, we found a novel dynamic behavior of the MTs in wihch entire MTs were moved inward from the leading edge toward the cell nucleus. This centripetal transport (CT) of MTs only occurred to those MTs that were oriented with their long axis parallel to the leading edge; radially oriented MTs were not transported centripetally. Both small bundles of MTs and individual MTs were observed to undergo CT at a rate of 0.63 × 0.37 μm/min. This rate was similar to the rate of CT of latex beads applied to the cell surface and of endogenous pinocytotic vesicles in the cytoplasm. When we imaged both MTs and pinocytotic vesicles, we found that the pinocytotic vesicles were ensheathed by a small group of parallel MTs that moved centripetally in concert with the vesicles. Conversely, we found many instances of MTs moving centripetally without associated vesicles. When cells were treated with nocodazole to depolymerize MTs rapidly, the rate of pinocytotic vesicle CT was inhibited by 75%. This suggests that centripetal transport of MTs may be involved in the movement of pinocytotic vesicles in cells. In conclusion, our results show that MTs in motile cells are redistributed by a novel mechanism, CT, that does not require changes in polymer length. The centripetally transported MTs may play a role in transporting pinocytotic vesicles in the cell. © 1995 Wiley‐Liss, Inc.
Visualization of the transverse cytoskeletal network in insect‐flight muscle by scanning‐electron microscopy
Authors: Trombitás Karoly , Pollack Gerald H. 
Published: February 2005

AbstractLocated at the level of the Z‐line, the transverse cytoskeletal network of insectflight muscle interconnects adjacent myofibrils with one another, and interconnects peripheral myofibrils with the cell membrane. This network has been presumed to keep myofibrils in register, or to distribute tension laterally among myofibrils. In this study, we used scanning‐electron microscopy to reveal details of the three‐dimensional arrangement of this network. The network is seen to interconnect longitudinal elements of the cytoskeletal network which surround each myofibril. The arrangement is not unlike that seen in vertebrate skeletal muscle. Interestingly, the transverse network makes contact with cell components such as dense bodies and mitochondria. Such contacts imply potential roles over and above those noted above. The network may be involved not only in mechanical function, but possibly also in intracellular communication. © 1995 Wiley‐Liss, Inc.
Changes of cell behavior by near‐infrared signals
Authors: Albrecht‐Buehler Guenter 
Published: February 2005

Abstract3T3 mouse fibroblasts responded differently to specific near‐infered signals than epithelial CV1 cell. Furthermore, signals with the same wavelength and energy changed the percentages of attracted and repelled 3T3 cells if their intensity modulation was altered. I found this result in a 22 month long study which established a spectrum of motile responses of 781 individual 3T3 cells and 148 CV1 cells to the near‐infrared emissions of microscopic, pulsating light sources using the infrared spot‐irradiation phase‐contrast (IRSIP) microscopic [Albrecht‐Buehler, 1991: J. Cell Biol. 114:493–502]. Thus the response of cultured, mammalian cells to near‐infrared light signals is not merely a matter of total energy absorption by cirtain cytoplasmic componets. Since it seems to depend on the cell type and the temporal pattern in which the light energy is emitted, it appears to imply the existence of a new kind of cellular information. © 1995 Wiley‐Liss, Inc.
Recent progress in lateral overgrowth of semiconductor structures from the liquid phase
Authors: Zytkiewicz Z. R. , Dobosz D. , Liu Y. C. , Dost S. 
Published: February 2005

AbstractThe article presents a short review of recent developments in epitaxial lateral overgrowth (ELO) of thin layers of III‐V compound semiconductors by liquid phase epitaxy (LPE) and also by liquid phase electroepitaxy (LPEE). The focus is on the relative contributions of various transport processes involved in ELO toward the growth of high quality, dislocation free thin layers of semiconductors with large width/thickness ratios. Results of our experimental and modelling studies on lateral overgrowth by LPE are used as examples. Furthermore, the application of LPEE for lateral overgrowth of compound semiconductors, a new emerging area of ELO technology, is discussed, and some experimental and numerical results are presented. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
A Monte Carlo study of the dependence of the habits of Kossel crystal on dynamic parameters during two‐dimensional growth
Authors: Prywer J. , Krukowski S. 
Published: February 2005

AbstractWe present the Monte Carlo simulation results, demonstrating that the habit of two‐dimensional growth of Kossel crystals depends on supersaturation and surface diffusion barrier. It is shown that at very small supersaturation, the surface diffusion plays dominant role and controls the resulting growth shapes. At higher supersaturation the growth habit is universal and does not depend on surface diffusion rates. Further increase of the supersaturation leads to unstable growth morphologies. These Monte Carlo results are analyzed using SHAPE package in order to derive the relative growth rates along different crystallographic directions. Using these data the dependence of the growth habit on the energetic parameters: bond energy and temperature and dynamic parameters: supersaturation and surface diffusion is given. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Determination of growth conditions and structure of SrAl0.5Ta0.5O3 : LaAlO3 : CaAl0.5Ta0.5O3 crystals
Authors: Aleksiyko R. , Berkowski M. , Fink‐Finowicki J. , Diduszko R. , Byszewski P. , Kikalejshvili‐Domukhovska R. 
Published: February 2005

Abstract(SrAl0.5Ta0.5O3)1‐x‐y(LaAlO3)x(CaAl0.5Ta0.5O3)y perovskite crystals of general formula ABO3 (where A = Sr1‐x‐yLaxCay and B = Al1/2+x/2Ta1/2‐x/2) were grown by the Czochralski and floating zone methods in wide a composition range. The experiments allowed us to determine regions on the composition diagram where solid solution crystals exist. The structure of the crystals at room temperatures was investigated by X‐ray measurements. Structure of the crystals at constant radius of B‐ions depends on the volume of a primitive perovskite unit cell. Thus, the structure undergoes transition from the cubic lattice of Fm3m + Pm3m space group symmetry through tetragonal (P4/mbm) to orthorhombic (Pbnm) with decreasing the primitive perovskite unit cell volume. One expects that with changing the temperature the crystals undergo second order structural phase transitions but no heat effects by differential scanning calorimetry were observed. There were no twins detected in the crystals with the cubic and tetragonal structures. The range of the lattice parameters variation and the high melting point indicate that these crystals may be used as substrates for HTSc, manganites or GaN epitaxial layers because of their high thermal and chemical stability.
Growth and optical characterization of Cd1‐xBexSe and Cd1‐xMgxSe crystals
Authors: Firszt F. , Wronkowska A. A. , Wronkowski A. , Łęgowski S. , Marasek A. , Męczyńska H. , Pawlak M. , Paszkowicz W. , Strzałkowski K. , Zakrzewski A. J. 
Published: February 2005

AbstractCd1‐xBexSe and Cd1‐xMgxSe solid solutions were grown from the melt by the high pressure Bridgman method. Optical, luminescence and photothermal properties of these materials were investigated. Spectroscopic ellipsometry was applied for determination of the spectral dependence of the complex dielectric function $ \tilde \varepsilon $(E) and refractive index n(E) at room temperature in the photon energy range 0.75‐6.5 eV for samples with optic axis (c‐axis) perpendicular to the air‐sample interface. The critical point (CP) parameters for E0 and E1 transitions were determined using a standard excitonic CP function to fit the numerically calculated differential spectra ∂2ε2/∂E2. The dispersion of the refractive index of the alloys was modelled using a Sellmeier‐type relation. The values of fundamental and exciton band‐gap energies were estimated from the ellipsometric and photoluminescence measurements. The origin of luminescence in Cd1‐xBexSe and Cd1‐xMgxSe was discussed. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Investigation of semi‐insulating InP co‐doped with Ti and various acceptors for use in X‐ray detection
Authors: Zdansky K. , Pekarek L. , Gorodynskyy V. , Kozak H. 
Published: February 2005

AbstractSemi‐insulating InP single crystals co‐doped with Zn and Ti and co‐doped with Ti and Mn were grown by Czochralski technique. Wafers of these crystals were annealed for a long time at a high temperature and cooled slowly. The samples were characterized by temperature dependent resistivity and Hall coefficient measurements. The binding energies of Ti in semi‐insulating InP co‐doped with Ti and Zn and co‐doped with Ti and Mn were found to differ which shows that Ti may occupy different sites in InP. The curves of Hall coefficient vs. reciprocal temperature deviate from straight lines at low temperatures due to electron and hole mixed conductance. The value of resistivity of the annealed semi‐insulating InP co‐doped with Ti and Mn reaches high resistivity at a reduced temperature easily achievable by thermo‐electric devices which could make this material useable in X‐ray detection. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Study on shaped single crystal growth and scintillating properties of Bi‐doped rare‐earth garnets
Authors: Novoselov A. , Yoshikawa A. , Nikl M. , Solovieva N. , Fukuda T. 
Published: February 2005

AbstractShaped single crystals of Bi:Gd3Ga5O12 (Bi = 0.102, 0.126 and 0.141 mol.%) and Bi:Y3Ga5O12 (Bi = 0.041, 0.047 and 0.061 mol.%) were grown by the micro‐pulling‐down method. Measured optical absorption spectra show an absorption band round 290 nm ascribed to the lowest energy 6s2→6s6p transition of Bi3+. Difference in the position of the emission spectra of Bi‐related bands in Gd3Ga5O12 (470 nm) and Y3Ga5O12 (314 nm) was explained by the lower local distortion of Bi polyhedron in Y3Ga5O12 host leading to smaller Stokes shift of only 0.36 eV. Unsuitability of Bi‐doping in the Gd3Ga5O12 host to get energy transfer from Gd3+ towards Bi3+ centers was concluded, while Bi‐doped Y3Ga5O12 could compete against Bi4Ge3O12 scintillator. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)