bluuebunny/crossref_metadata_2025_split huggingface dataset:
Molecular analysis of human monogenic diseases
Authors: Davies K. E. , Robson K. J. H. 
Published: February 2005

AbstractOver one hundred genes have been isolated from the human genome and shown to be causally related to specific human genetic diseases. Studies with gene‐specific probes have demonstrated that the mutations resulting in a particular phenotype are highly heterogeneous as a group, ranging from alterations in transcription or RNA processing in the nucleus, through to errors in mRNA translation in the cytoplasm. Even where the gene‐specific probe is not available, defects have been localized to chromosomal regions by family studies. Recently developed methods for moving along the chromosome from a linked marker to the mutation are resulting in rapid advances in the understanding of many monogenic disorders.
Increasing bacterial disease resistance in plants utilizing antibacterial genes from insects
Authors: Jaynes Jesse M. , Xanthopoulos Kleanthis G. , Destéfano‐Beltrán Luis , Dodds John H. 
Published: February 2005

AbstractThe introduction of genes into plants encoding potent antibacterial proteins, derived from insects, may significantly augment the level of their resistance to bacterial disease. Using modern techniques, genes of choice can be introduced into plant tissue and this tissue can be manipulated to produce viable plants. The potato has been chosen as the model system, not only because of its plasticity of development, which allows for the relatively easy regeneration of whole plants from transformed tissue, but also because the potato ranks among the top four plants in the world in terms of economic importance.
The origin, development and regulation of osteoclasts
Authors: Osdoby Philip , Krukowski Marilyn , Oursler Merry Jo , Salino‐Hugg Teresa 
Published: February 2005

AbstractOsteoclasts, the multinucleated cells primarily responsible for dissolution of bone tissue, form by fusion of precursors that circulate in the bloodstream. A variety of factors have been shown to affect the mature osteoclast and its progenitor cell, such as calcium‐regulating hormones, products of the immune system, and constituents of the arachidonic acid cascade. To date, however, the osteoclast precursor has not been identified. Furthermore, there is limited information on the factors that influence osteoclast development and regulation, reflecting in part the paucity of data on the osteoclast cell surface. Recent progress in understanding osteoclasts formation and function is discussed.
The potential of adipokinetic hormone to teach us about neuropeptides
Authors: Schaffer Martin H. , Noyes Barbara E. 
Published: February 2005

AbstractGenetic manipulation and purification techniques are facilitating research into the biology of arthropod neuropeptides. The red pigment concentrating hormone (RPCH)/ adipokinetic hormone (AKH) family are a conserved group of peptides which were first recognized for their hormonal activities. Biosynthesis of AKH in the grasshopper seems to proceed via a large protein precursor (12 kDa) in the cell body of the neuron, which implies precise coordination of synthesis and neural activity. Beginning with a 10 amino acid stretch of known precursor protein sequence, an oligonucleotide primer approach is being used to clone a recombinant AKH gene. Once achieved, this will allow fundamental questions on the biochemistry and physiology of neuropeptides to be addressed. Such work in an arthropod system raises the intriguing possibility of studying neuropeptide level and synthetic activity in single, defined neurons.
Approaching the biochemistry of virus multiplication
Authors: Cohen Seymour S. 
Published: February 2005

AbstractThe evolution of research on the biochemistry of virus multiplication cannot be understood without knowing something of the structure of biochemistry and of virology before, during and immediately after World War II. My own research on virus multiplication began after studies on plant viruses and wartime research on the rickettsial components of the typhus vaccine, all of which involved work on the nucleic acids. Interest in the chemotherapy of virus disease led to a search for a model system. A simple methodology for handling phage systems enabled biochemists to examine infected cells. The fortuitous use of an extremely virulent phage group (the T‐even phages) which evoke marked changes in polymeric products without affecting the production of energy and small building blocks facilitated these studies. An exaggerated synthesis of viral DNA by these phages concentrated our attention on the origins of this substance, which proved to contain a new pyrimidine deoxyribonucleotide, synthesized by a novel virus‐determined enzyme. The generality of the existence of virus‐induced enzymes and other proteins may be the key to a chemotherapy of virus infection.
Molecular mimicry of carbohydrate and protein structures by hybridoma antibodies
Authors: Olsson Lennart 
Published: February 2005

AbstractA large proportion of tumour‐associated antigens seem to be determined by carbohydrate structures. Advances in the study of the antigenicity of cell‐surface carbohydrates have been hampered by the absence of advanced monoclonal hybridoma technology comparable to that available for the study of protein antigens. Monoclonal antibodies have been raised against a carbohydrate epitope (43–9F) that is associated with the proliferative features of squamous lung carcinomas. These were used in turn to generate anti‐idiotype antibodies with homology to 43–9F. The method and its possible applications are described, together with a procedure to detect rare cell membrane variants within large populations.
What are the functions of kinesin?
Authors: Sheetz Michael P. 
Published: February 2005

AbstractA variety of intracellular motile processes involve the directed movement of particles along microtubules, including organelle transport, endoplasmic reticulum extension, and movements in mitosis. Recently, a microtubule‐dependent motor protein, kinesin, was purified and was found to be present in a soluble form in a wide variety of organisms and tissues. Because microtubules provide polar pathways over long distances within cells, kinesin and the motors which move in the opposite direction to kinesin on microtubules provide a mechanism for directed communications within cells. The possible roles of kinesin and other soluble microtubule‐dependent motors in intracellular motile functions are discussed in the light of recent studies of the reconstitution of organelle motility with isolated components.
Towards the genetic dissection of mitosis in Drosophila
Authors: Ripoll Pedro , Casal José , González Cayetano 
Published: February 2005

AbstractCell division is an universal process the aim of which is the equitable distribution of subcellular organelles from single cells to their daughters. The extraordinary accuracy with which the genetic material is partitioned requires a complex machinery involving many gene products. Genetic approaches can be used to identify the relevant components and processes, and mutational analysis of loci essential for cell division has been carried out in several eukaryotes, in particular fungi and mammalian cells in culture. Recently, this type of analysis has been extended to Drosophila, an ideal eukaryote for genetic studies. We will review here the genetic dissection of mitosis in Drosophila melanogaster, discussing recent findings of interest and the methodological problems that have been encountered.
Evidence mounts for the role of gap junctions during development
Authors: Green Colin R. 
Published: February 2005

AbstractWhile evidence for the role of gap functions, particularly during development, has been mounting, it has remained largely correlative, linking structure with presumed functions. With the recent advent of functional antibodies raised to the junctional protein, however, it has become possible to study the role of gap junctions more directly. There is now considerable evidence indicating that they play a vital role in tissue pattern formation and differentiation by allowing direct cell‐to‐cell transfer of developmental signals or morphogens.
The role of interferon in the regulation of virus infections by cytotoxic lymphocytes
Authors: Welsh Raymond M. , Yang Hyekyung , Bukowski Jack F. 
Published: February 2005

AbstractInterferon (IFN) induced during a virus infection mediates antiviral effects both by direct inhibition of virus replication and by influencing the proliferation, differentiation, and chemotaxis of cyto‐toxic lymphocytes which control the infection. Cells from tissue taken from virus‐infected mice are conditioned by IFN to resist lysis by natural killer (NK) cells, while they become increasingly susceptible to lysis by cytotoxic Tlymphocytes (CTL). This is due to marked IFN‐induced biochemical changes, including an up‐regulation of major histocompatibility antigens, which are targets for CTL. Cytopathic viruses, which inhibit cellular RNA and protein synthesis, render target cells refractory to IFN‐mediated protection against NK cells, thereby providing a mechanism for NK cells to mediate antiviral effect by preferentially lysing virus‐infected but not uninfected cells.
Cellular transformation, tyrosine kinase oncogenes, and the cellular adhesion plaque
Authors: Kellie Stuart 
Published: February 2005

AbstractThe study of adhesion plaques in normal and transformed cells provides a series of phenotypic markers by which the process of transformation can be followed. Several proteins which are concentrated in adhesion plaques have now been identified; a few of these can act as targets for tyrosine kinase. In an attempt to characterize the relationship between tyrosine phosphorylation and cell transformation, the reactions of three such proteins – vinculin, talin and integrin – with a range of tyrosine kinase oncogene products have been studied in detail.
On transition metal ions and protein interactions in chromatin
Authors: Saavedra Raul A. 
Published: February 2005

AbstractMetal ions may play an essential role in chromatin organization and, thus, be main actors in the gene expression drama. A model is proposed here for the interaction of DNA‐binding transcriptional regulatory proteins with histone H3 via coordinated metal ions and discussed in relation to the conversion of nucleosomal ‘closed’ to ‘open’ states.
The mechanistic role of enhancer elements in eukaryotic transcription
Authors: Jeang Kuan‐Teh , Khoury George 
Published: February 2005

AbstractEnhancer elements are short stretches of nucleotides operationally defined by their cis‐acting ability to increase the transcription of nearby genes. They function relatively independently of position, orientation, and distance. Some show narrow tissue specificity while others permit constitutive expression in many different cell types. Although the first enhancer was described for simian virus 40 (SV40) more than five years ago, its mechanism of action has remained unclear. This review describes some of the models proposed to explain the physical role of enhancers in eukaryotic transcription.
Neuropeptides, second messengers and insect molting
Authors: Gilbert Lawrence I. , Combest Wendell L. , Smith Wendy A. , Meller Victoria H. , Rountree Dorothy B. 
Published: February 2005

AbstractInsect molting is elicited by a class of polyhydroxylated steroids, ecdysteroids, that originate in the prothoracic glands. Ecdysteroid synthesis in the prothoracic glands is controlled in large measure by a peptide hormone from the brain, prothoracicotropic hormone (PTTH), which exists in two forms and is released into the general circulation as a result of environmental and developmental cues. The means by which PTTH activates the prothoracic glands has been examined at the cellular level and the data reveal the involvement of cAMP, calcium, calmodulin, cAMP‐dependent protein kinase and the ultimate phosphorylation of a 34 kDa protein tentatively identified as ribosomal protein S6.
Pre‐implantation diagnosis
Authors: Monk Marilyn 
Published: February 2005

AbstractThe access to human pre‐implantation embryos that is afforded by procedures now developed for the treatment of infertility presents the possibility of very early prenatal diagnosis, before implantation in the uterus, of certain genetic diseases. Only the normal embryos would be replaced in the mother for initiation of implantation and pregnancy. Early experiments on a mouse model for Lesch‐Nyhan syndrome (HPRT‐deficiency) show that pre‐implantation diagnosis of genetic disease is feasible.
Anterior‐posterior pattern formation: An evolutionary perspective on genes specifying terminal domains
Authors: Strecker Teresa R. , Lengyel Judith A. 
Published: February 2005

AbstractThe Drosophila anterior‐posterior pattern genes of the terminal class, particularly the tailless gene, affect structures derived from the acron and the tail region of the embryo. These domains correspond in position and function to asegmental domains at the termini of annelids and more primitive insect embryos. This suggests that terminal genes in Drosophila may have originated in an ancestor common to both annelids and arthropods, and thus that the specification of termini in these metameric organisms is an ancient, evolutionarily conserved process.
Genetics of surface protein variation in Neisseria gonorrhoeae
Authors: Murphy George L. , Cannon Janne G. 
Published: February 2005

AbstractNeisseria gonorrhoeae, the bacterium that causes the sexually transmitted disease gonorrhea, demonstrates extensive antigenic heterogeneity in its surface components. The organism has the capacity to switch on and off the synthesis of different versions of components such as pili, outer membrane proteins, and lipopolysaccharide. Recent studies have shown that the gonococcus uses novel and complex mechanisms, of types not described previously, to store different versions of genetic information for surface proteins, and to regulate expression of those genes.
The control of pattern as seen in the integument of an insect
Authors: Wigglesworth V. B. 
Published: February 2005

AbstractIn recent years, the phenomena of hormonal control, embryonic determination and pattern formation have been receiving intensive scrutiny from molecular biologists. In the following «Roots» contribution, Professor Sir Vincent B. Wigglesworth reviews some of the seminal work that he did on these subjects in the insect Rhodnius prolixus.
The chromatin domain as a unit of gene regulation
Authors: Goldman Michael A. 
Published: February 2005

AbstractThe process by which the genetically identical cell lineages of a multicellular organism acquire the propensity to express distinct arrays of gene products is among the most significant and fascinating questions in modern biology. Not surprisingly, this complex process requires control at several levels, each level providing a condition that is necessary but not sufficient for transcription to occur. Evidence suggests that one level of control concerns a region of DNA much larger than the transcription unit itself – the chromatin domain. This domain must be in a specific chromatin conformation in order to permit transcription; other control mechanisms may be required to bring about overt transcription. A hypothesis concerning the nature of chromatin domains and the relationship between early replication and transcription potential is presented.
Principles of antibody catalysis
Authors: Lerner Richard A. , Benkovic Stephen J. 
Published: February 2005

AbstractAntibodies have now been shown to catalyze a variety of chemical transformations, including hydrolytic, concerted, and bimolecular reactions. The inherent chirality of the antibody binding pocket has been exploited to exert precise stereochemical control over their catalyzed reactions. The mechanisms by which antibodies catalyze reactions are not expected to differ in any general way from those of natural enzymes. Antibodies use their binding energy to stabilize species of higher free energy which appear along the reaction coordinate or effect general acid/base catalysis. The advent of catalytic antibodies promises new catalysts that extend the range of catalysis by proteins to chemical transformations that were not required during the evolution of enzymes.
The Leghaemoglobins
Authors: Powell Richard , Gannon Frank 
Published: February 2005

AbstractThe importance of nitrogen fixation, in assimilation of atmospheric dinitrogen for eventual storage in plant proteins, has resulted in extensive study of both plant and bacterial genes involved in this process. To date, the major plant genes analysed are the leghaemoglobins. These are closely related to the animal globins, allowing us to compare their gene organization, expression and evolution. We review here the progress and results of leghaemoglobin analysis and the comparisons with the related animal globins.
The Gap junction proteins: Vive la différence!
Authors: Kistler Joerg , Bullivant Stanley 
Published: February 2005

AbstractThe intercellular junctions connecting the cytoplasms of fibre cells in the mammalian lens have until recently been regarded as a class of junction which is fundamentally different from that of the gap junctions in other organs. Recent observations, however, suggest that the lens junctions fit protein topology predictions common for all gap junctions. While the homologous peptide portions are predicted to form the channels, the divergent peptide portions of the gap junction polypeptides may adapt channel activity to the special tissue requirements.
Structural elements regulating zein gene expression
Authors: Thompson Gary A. , Larkins Brian A. 
Published: February 2005

AbstractZeins are a group of alcohol‐soluble proteins that are synthesized in the endosperm of developing maize seeds. These proteins are encoded by a large number of genes located on several chromosomes; based upon the number of mutants that have been isolated, zein gene regulation is complex. Comparisons of gene flanking regions reveal conserved sequences that may be important for their regulation. Studies of transformed plant tissues support the assertion that cis‐acting elements with the 5′ flanking regions of zein genes are required for accurate transcription. Although the genes are transcribed in transgenic tobacco and petunia plants, they are not properly regulated. This appears to be due to transcriptional effects rather than protein or mRNA instability.
Gene structure and function of granulocyte colony‐stimulating factor
Authors: Nagata Shigekazu 
Published: February 2005

AbstractIn the last few years, the molecular and genetic nature of the granulocyte colonystimulating factor, which controls proliferation and differentiation of neutrophils, has been characterized. Recent clinical application of G‐CSF proves that this hormone is effective in the treatment of patients suffering from neutropenia.
Evolutionary aspects of urea cycle enzyme genes
Authors: Takiguchi Masaki , Matsubasa Tadashi , Amaya Yoshihiro , Mori Masataka 
Published: February 2005

AbstractThe functions and expression pattern of urea cycle enzymes have undergone considerable changes during the course of evolution. Sequence analyses shows that urea cycle enzymes from mammals are homologous to microbial enzymes of the arginine‐metabolic pathway. Recently, an unexpected relationship was found between argininosuccinate lyase (EC 4.3.2.1), the fourth enzyme of the cycle, and δ‐crystallin, a lens structural protein of birds and reptiles.
The saga of IMAC and MIT
Authors: Sulkowski Eugene 
Published: February 2005

AbstractImmobilized Metal‐ion Affinity Chromatography, IMAC, has been gaining in popularity as the purification technique of choice for proteins and peptides. IMAC of proteins on transition metals (Co, Ni, Cu, Zn) can be rationalized in terms of the coordination of histidine residues. Brief accounts of the principles of IMAC, its anticipated development and plausible applications are presented. Metal Ion Transfer, MIT, may offer an efficient means to deplete a metal ion from a metalloprotein or, conversely, to charge its apo form with a metal.
The carbonic anhydrases: Widening perspectives on their evolution, expression and function
Authors: Tashian Richard E. 
Published: February 2005

AbstractNow, some 55 years after its discovery in bovine red cells, carbonic anhydrase (CA), in all its varied forms, continues to challenge and intrigue physiologists, biochemists and molecular geneticists. This is so because of an increasing awareness of the many apparently diverse functions of the different CA isozymes encoded by this large multigene family, the continuing discovery of new CA, or CA‐related, genes, and the extensive variation in their hormonal control, cellular expression and subcellular localization.
Do ribosomes regulate mitochondrial RNA synthesis?
Authors: Jacobs Howard T. 
Published: February 2005

AbstractThe levels of different classes of mitochondrially encoded transcripts are developmentally regulated in sea urchin embryos, as a result of selection between mutually exclusive synthetic pathways. I propose a simple model to explain these observations, based on a dual role for mitochondrial ribosomes and translation factors in RNA synthesis as well as in translation. This effect may be exerted either at the transcriptional or post‐transcriptional level (or both), and is potentially generalizable to mammalian mtDNA and to other systems.
Morphogens in chick limb development
Authors: Brickell P. M. , Tickle C. 
Published: February 2005

AbstractRetinoic acid is a good candidate for a morphogen in chick limb bud development. The challenge now is to determine how retinoic acid interacts with limb bud cells and how the retinoic acid signal is integrated with other signals to mould and pattern the developing limb.
Temporally regulated expression of insulin and insulin‐like growth factors and their receptors in early mammalian development
Authors: Heyner Susan , Smith Robert M. , Schultz Gilbert A. 
Published: February 2005

AbstractRecent studies of early development in a number of ivertebrate and vertebrate species have suggested that growth factors and their receptors may play important roles in differentiation as well as cell proliferation. In the mouse embryo, the expression of the receptors for insulin and insulin‐like growth factors I and II (IGF‐I and ‐II) are temporally regulated. The ontogeny of receptor and ligand expression within the insulin and IGF gene family suggests that the very earliest stages of mammalian embryogenesis may be subject to regulation by autocrine and paracrine factors from maternal and embryonic sources.
Cell polarity and development of the first epithelium
Authors: Wiley Lynn M. , Kidder Gerald M. , Watson Andrew J. 
Published: February 2005

AbstractIn the 4 1/2 to 5 days between fertilization and implantation, the mouse conceptus must gain the abilities to implant and produce an embryo. Each of these is the sole developmental responsibility of one of two cell types forming the blastocyst, trophectoderm and inner cell mass (ICM), respectively. Trophectoderm is a polarized transporting epithelium while the ICM is an aggregate of non‐epithelial pluripotent stem cells. These two cell types originate from the division of polar blastomeres when their cleavage furrows parallel their apical surfaces. Blastomeres polarize in response to asymmetric cell–cell contact, and understanding the mechanism of this induction is regarded as the key to understanding the origin of trophectoderm and ICM. Here we propose a model based on transcellular ion current loops for the induction of cell polarity during the development of the first epithelium, trophectoderm.