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D R Maglott

Publications and source records attributed to D R Maglott.

At least 19 recordsLinked to original sources
PubMed2001

RefSeq and LocusLink: NCBI gene-centered resources.

Thousands of genes have been painstakingly identified and characterized a few genes at a time. Many thousands more are being predicted by large scale cDNA and genomic sequencing projects, with levels of evidence ranging from supporting mRNA sequence and comparative genomics to computing ab initio models. This, coupled with the burgeoning scientific literature, makes it critical to have a comprehensive directory for genes and reference sequences for key genomes. The NCBI provides two resources, LocusLink and RefSeq, to meet these needs. LocusLink organizes information around genes to generate a central hub for accessing gene-specific information for fruit fly, human, mouse, rat and zebrafish. RefSeq provides reference sequence standards for genomes, transcripts and proteins; human, mouse and rat mRNA RefSeqs, and their corresponding proteins, are discussed here. Together, RefSeq and LocusLink provide a non-redundant view of genes and other loci to support research on genes and gene families, variation, gene expression and genome annotation. Additional information about LocusLink and RefSeq is available at http://www.ncbi.nlm.nih.gov/LocusLink/.

Animals↗
PubMed2000

NCBI's LocusLink and RefSeq.

The NCBI has introduced two new web resources-LocusLink and RefSeq-that facilitate retrieval of gene-based information and provide reference sequence standards. These resources are designed to provide a non-redundant view of current knowledge about human genes, transcripts and proteins. Additional information about these resources is available on the LocusLink web site at http://www.ncbi.nlm.nih.gov/LocusLink/

Database Management Systems↗
PubMed1998

The human proteinase-activated receptor-3 (PAR-3) gene. Identification within a Par gene cluster and characterization in vascular endothelial cells and platelets.

Proteolytically activated receptors (PARs) represent an emerging subset of seven transmembrane G protein-coupled receptors that mediate cell activation events by receptor cleavage at distinct scissile bonds located within receptor amino termini. Differential genomic blotting using a yeast artificial chromosome known to contain the PAR-1 and PAR-2 genes identified the PAR-3 gene within a PAR gene cluster spanning approximately 100 kilobases at 5q13. The PAR-3 gene is relatively small (approximately 12 kilobases); and, like the PAR-1 and PAR-2 genes, it displays a two-exon structure, with the majority of the coding sequence and the proteolytic cleavage site contained within the larger second exon. Sequence analysis of the 5'-flanking region demonstrates that the promoter is TATA-less, similar to that seen with PAR-1, with the identification of nucleic acid motifs potentially involved in transcriptional gene regulation, including AP-1, GATA, and octameric sequences. PAR-3 transcripts were apparent in human vascular endothelial cells, although at considerably lower levels than those of PAR-1 and not significantly modulated by the endothelial cell stimulus tumor necrosis factor-alpha. Likewise, although PAR-3 mRNA was evident in human platelets, receptor cell surface expression was modest (approximately 10%) compared with that of PAR-1. Thus, although PAR-3 is postulated to represent a second thrombin receptor, its modest endothelial cell and platelet expression suggest that PAR-3 activation by alpha-thrombin is less relevant for physiological responses in these mature cells. Rather, given its disparately greater expression in megakaryocytes (and megakaryocyte-like human erythroleukemia cells), a regulatory role in cellular development (by protease activation) could be postulated.

Amino Acid Sequence↗
PubMed1997

The human thrombin receptor and proteinase activated receptor-2 genes are tightly linked on chromosome 5q13.

The thrombin receptor (TR) and proteinase activated receptor-2 (PAR-2) may represent the prototypes of an emerging family of cell-surface receptors that effect cell activation events mediated by serine proteases generated during inflammatory, fibrinolytic or haemostatic-regulated pathways. To further characterize the molecular genetics of these receptors, we have refined the genetic and physical mapping of both PAR-2 and TR. Utilization of two distinct radiation hybrid mapping panels with different levels of resolution demonstrated that both genes are tightly linked to the microsatellite markers D5S424, D5S1977, D5S2529 and D5S2596 (in order of decreasing LOD scores, from 13.7 for D5S424 to 7.7 for D5S2596). Physical mapping using yeast artificial chromosomes (YACs) and inversion field gel electrophoresis demonstrated that they are maximally separate by 90 kb. If the association of TR and PAR-2 genes resulted from a relatively recent gene duplication event from a common ancestral gene, these observations provide a general framework for the identification of gene transcripts representing alternative proteolytically activated receptors which may be clustered within this region of the human genome. These observations are especially relevant given recent evidence that murine and human platelets express alternative signalling mechanisms or receptors for thrombin.

Animals↗
PubMed1996

Regional assignment and tissue expression of twenty-three expressed sequence tags (ESTs) from human chromosome 5.

Regional localization and expression patterns are reported for 19 expressed sequence tags (ESTs) from human chromosome 5, two of which were derived from the same transcript. Two of the ESTs correspond to genes not previously characterized in humans: a stress-activated protein kinase and nicotinamide nucleotide transhydrogenase. Expression was determined by three methods: Northern blots, PCR from tissue-specific cDNA libraries, and sequence sampling from EST sequencing projects. Six of the ESTs show no expression, and EST01986 appears to be expressed predominantly in the brain by all methods tested.

Chromosome Mapping↗
PubMed1995

Integration of transcript and genetic maps of chromosome 16 at near-1-Mb resolution: demonstration of a "hot spot" for recombination at 16p12.

A single mapping resource, a mouse/human somatic cell panel with average distance between breakpoints of 1.2 Mb and a potential resolution of 1 Mb, has been utilized to integrate the genetic map and a transcript map of human chromosome 16. This map includes 141 genetic markers and 200 genes and transcripts. The localization of four genes (CHEL3, TK2, TRG1, and MMP9) reported to map to chromosome 16 could not be confirmed, and for three of these localizations to other human chromosomes are reported. A correlation between genetic and physical distance over a region estimated to be 23 Mb on the short arm of chromosome 16 identified an interval demonstrating a greatly increased rate of recombination where, in females, 1 cM is equivalent to a physical distance of 100 kb.

Animals↗
PubMed1994

Chromosome assignment of human brain expressed sequence tags (ESTs) by analyzing fluorescently labeled PCR products from hybrid cell panels.

Sixty-three human brain cDNA sequences were newly assigned to individual human chromosomes. Ten of these were subregionally localized, and one was also mapped in the mouse genome. Four previously reported assignments were refined. PCR primers were designed from expressed sequence tags (ESTs) and tested for specific amplification from human genomic DNA. DNA was then amplified, often in multiplexed PCR reactions, using DNA from somatic cell hybrid mapping panels as templates. The amplification products were identified using an automated fluorescence detection system. Chromosomal assignments were made by discordancy analysis. Thirteen newly localized cDNAs exhibited homology to previously reported sequences. EST01471 was shown to correspond to human microtubule-associated protein 1B (MAP1B), confirming the previous mapping of this gene to human chromosome 5. Other genes tentatively assigned to chromosomes based on these results were a component of the signal peptide receptor of the endoplasmic reticulum (EST00745) and a cyclic AMP-regulated phosphoprotein (EST01041) on chromosome 1, a protein phosphatase 2A 55-kDa regulatory subunit (EST01650) on chromosome 4, an NAD(P) transhydrogenase (EST01744) on chromosome 5, ribosomal proteins L1a or L1b (EST01627) and L18a (EST01583), a brain transcription factor (BF-1, EST00795) on chromosome 14, a milk fat globule membrane-related protein (EST01678) on chromosome 15, a putative peptide initiation factor (EST00675) on chromosome 17, thiosulfate sulfurtransferase (TST) on chromosome 22, and moesin (MSN) (EST00896) and a human equivalent of rat spot 14 (S14) (EST00887) on Xp11-->cen and Xpter-->p21.3, respectively.

Animals↗
PubMed1992

Chromosomal assignment of 38 human brain expressed sequence tags (ESTs) by analyzing fluorescently labeled PCR products from hybrid cell panels.

We have localized 38 human brain cDNA sequences to individual human chromosomes. PCR primers were designed from expressed sequence tags and tested for specific amplification from human genomic DNA. The sizes of amplification products from DNA of somatic cell hybrid mapping panels were determined electrophoretically using an automated fluorescence detection system. Chromosomal assignments were made by discordancy analysis.

Animals↗
PubMed1985

Dissociation of cells from sea urchin embryos alters the synthesis of actins and other proteins.

The effects of altered cellular microenvironments on patterns of protein synthesis at various periods during sea urchin development were quantitated by comparing the relative incorporation of [35S]methionine into selected polypeptides of intact embryos and cells dissociated from them. The effects of increasing times of reassociation were also determined. Quantitative, but not qualitative, differences in incorporation were noted. Actins, as well as heterogeneous acidic polypeptides with an Mr of about 80 kDa, showed increased incorporation in dissociated cells labeled at the time control embryos were recently hatched blastulae. Labeling of another acidic group of polypeptides with an Mr of about 100 kDa was decreased. Possible mechanisms regulating these shifts in incorporation were investigated by the use of inhibitors. The dissociation-triggered changes were insensitive to actinomycin D, cordycepin, dibutyryl cAMP, 3-isobutyl-1-methylxanthine, and trifluoperazine; however, the latter two stimulated incorporation into some polypeptides in intact blastulae. Age-dependent shifts in incorporation were also detected in both intact embryos and dissociated/reassociating cells.

Actins↗
PubMed1985

Two-dimensional electrophoretic analysis of major phosphoproteins of the sea urchin, Arbacia punctulata.

Phosphoproteins of hatched blastulae, gastrulae, and pluteus larvae of the sea urchin, Arbacia punctulata, were labeled in vivo with [32P]O4 and analysed by 2-dimensional polyacrylamide gel electrophoresis and autoradiography. At least 60 phosphoproteins were resolved. Some of these showed different relative intensities of labeling at the embryonic periods monitored. Some embryonic phosphoproteins were characterized by cell fractionation and by comparing autoradiograms with Coomassie-blue staining patterns and [35S]methionine labeling patterns. Neither actin nor tubulin phosphorylation was detected. No differences in phosphorylation were detected in dissociated and partially reassociated blastula cells relative to each other and to intact embryonic controls.

Actins↗
PubMed1984

Diamide reversibly induces a stress response in the sea urchin, Arbacia punctulata.

Sea urchin blastulae were treated with two concentrations (0.54 and 0.72 mM) of diamide, a sulfhydryl oxidant, after hatching. These treatments increased the relative synthesis of one set of embryonic proteins while decreasing that of another. This was demonstrated by quantitating the incorporation of [35S]methionine into polypeptides separated by 2-dimensional polyacrylamide gel electrophoresis (2D PAGE). These shifts were dose dependent and apparently reversible after the embryos had regenerated reduced sulfhydryls. Those proteins showing increased incorporation migrated at the same position by 2D PAGE as heat shock proteins, suggesting that diamide was inducing a stress response. Diamide also caused some developmental aberrations at low frequency, and reversibly inhibited ciliary beating.

Animals↗