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D J Gilbert

Publications and source records attributed to D J Gilbert.

At least 91 records · Page 5Linked to original sources
PubMed1998

Structure of the gene encoding the ubiquitin-conjugating enzyme Ubcm4, characterization of its promoter, and chromosomal location.

Ubiquitin-conjugating enzymes (E2 or Ubc) play a key role in the post-translational modification of proteins by ubiquitylation. They are encoded by a large family of genes that are closely related to each other. In this paper we present the first complete structural analysis, including the promoter and the chromosomal location, of a member of this family, the mouse Ubcm4 gene. At the genomic level the Ubcm4 gene spans approx. 50kb and is composed of four exons. Only about 1% of the total gene codes for amino acids. The four different Ubcm4 specific RNAs encode the same protein and differ only in the length of the 3' untranslated region. The polyadenylation signals used by the four different RNAs are all within the 3' terminal exon. At the 5' end of the gene, multiple transcriptional start sites were mapped within a region of 25bp. The region proximal to the initiation sites does not contain a TATA box and is not GC-rich. Transient chloramphenicol acetyltransferase assays, however, showed that this region can promote the expression of a reporter gene and that 15bp upstream of the first initiation site were sufficient for basal expression. The Ubcm4 gene was mapped by interspecific backcross analysis to the proximal region of mouse chromosome 16.

Amino Acid Sequence↗
PubMed1998

Genetic characterization of the murine Ym1 gene and identification of a cluster of highly homologous genes.

The murine Ym1 gene belongs to a family of mammalian genes that are homologous to the chitinases from lower organisms, such as insects, nematodes, bacteria, and plants. All of these homologous mammalian proteins (except one member) have no demonstrable chitinase activity and therefore cannot be considered chitinases. The biological functions of these proteins remain unknown. However, these proteins may function through binding to carbohydrate polymers. In an effort to characterize the murine Ym1 gene better, we have delineated its genomic structure. We mapped the chromosomal location of the Ym1 gene to a central region of mouse chromosome 3 (in the region syntenic to human chromosome 1p13) and that of another murine chitinase-like gene, Brp39, to a central region of mouse chromosome 1 (in the region syntenic to human chromosome 1q31). In addition, we identified several genes highly homologous to Ym1 that cluster at the Ym1 locus. We show that these genes are expressed selectively in different mouse tissues.

Amino Acid Sequence↗
PubMed1998

Genomic organization, expression and chromosomal localization of the mouse Slug (Slugh) gene.

The Slug gene encodes a zinc finger protein implicated in the generation and migration of neural crest cells in several vertebrate species. Here we describe the genomic organization and chromosomal localization of the mouse Slug (Slugh) gene. The mouse Slug gene consists of three exons spanning approx. 4 kb. Northern blot analysis of RNA isolated from several tissues of adult mice revealed the presence of a single 2.1 kb transcript. The chromosomal location of mouse Slug was determined by interspecific backcross analysis. The mapping results indicated that Slugh is located in the proximal region of mouse chromosome 16.

Animals↗
PubMed1998

BID, a proapoptotic BCL-2 family member, is localized to mouse chromosome 6 and human chromosome 22q11.

BID is a proapoptotic member of the BCL-2 family of cell death regulators. BID shares sequence homology with other members of the family within a single alpha-helical domain, BH3. BH3 is required for BID to interact with BCL-2 and BAX, as well as for its function as a death agonist. We have isolated and characterized mouse Bid and human BID genomic clones. The sequence for BID is encoded within five exons. We used interspecific backcross analysis to localize Bid to the distal region of mouse chromosome 6 near the Atp6e locus. Fluorescence in situ hybridization analysis localized human BID to a syntenic human region, chromosome 22q11, close to the BCR-1 gene.

Animals↗
PubMed1998

The CC chemokine 6Ckine binds the CXC chemokine receptor CXCR3.

We cloned the mouse homologue of the chemokine receptor CXCR3, which is located in mouse chromosome X. We screened a large panel of chemokines for their ability to induce a calcium flux in mouse CXCR3-transfected cells and identified a new ligand for this receptor, the recently reported CC chemokine 6Ckine. This represents an example of a CC chemokine, which binds to a CXC chemokine receptor. Like other ligands of this receptor, 6Ckine has angiostatic properties. 6Ckine is known to chemoattract T cells. In line with this, CXCR3 is expressed preferentially in Th1 cells and in lymphoid organs of the IL-10(-/-) mouse that develops chronic colitis. Its ability to attract T cells as well as its angiostatic properties suggest that 6Ckine may be an effective anti-tumor agent.

Amino Acid Sequence↗
PubMed1998

Structure of the human paralemmin gene (PALM), mapping to human chromosome 19p13.3 and mouse chromosome 10, and exclusion of coding mutations in grizzled, mocha, jittery, and hesitant mice.

Paralemmin is a newly identified protein that is associated with the plasma membrane and with intracellular membranes through a lipid anchor. It is abundant in brain, is expressed at intermediate levels in the kidney and in endocrine cells, and occurs at low levels in many other tissues. As it is a candidate for genetic disorders that affect membrane functions, we have determined the structure of the human paralemmin gene, PALM, showing that it is organized into nine exons. Moreover, we have performed chromosomal assignments of the human and mouse paralemmin genes, localizing them to regions of homology at human 19p13.3 and the central mouse chromosome 10. Finally, mutation analysis using RNA from mice homozygous for the mutant genes grizzled (gr), mocha (mh), mocha 2J (mh2J), jittery (ji) and hesitant (ji(hes)), which map to this area, excluded mutations in their Palm coding sequences.

Amino Acid Sequence↗
PubMed1998

Cloning and characterization of a novel class II phosphoinositide 3-kinase containing C2 domain.

Phosphoinositide 3-kinases (PI3Ks) have been shown to play critical roles in cell growth, differentiation, survival, and vesicular transport. Class II PI3Ks have been recently identified in mouse and human (PI3K-C2 alpha/m-p170/m-cpk and HsC2-PI3K) and in Drosophila (PI3K 68D/cpk) which contain C2 domain at the C-terminus. However, their physiological function is largely unknown. We report here cloning and characterization of murine PI3K-C2 gamma, a novel class II PI3K. The catalytic domain as well as C2 domain are highly conserved in the Class II PI3K family, while the N-terminal regions of these proteins share little similarity. Unlike other Class II PI3Ks, PI3K-C2 gamma exclusively expressed in the liver, and a N-terminal truncated form was found in lung and a certain hematopoietic cell line. Specific antiserum against PI3K-C2 gamma precipitated PI3K activity from the membrane fraction of mouse liver but not from heart. Recombinant PI3K-C2 gamma exhibited a restricted lipid substrate specificity; it phosphorylated phosphatidylinositol (PtdIns) and PtdIns4P but not PtdIns(4,5)P2. Deletion mutations revealed that both the N-terminal region and the C2 domain were critical for enzymatic activity. The murine PI3K-C2 gamma gene locus was mapped to the distal region of mouse chromosome 6 in a region of homology with human chromosome 12p, which is distinct from the position of HsC2-PI3K. Cloning and biochemical characterization of the third member of class II PI3Ks provide a new insight into the function of this subfamily of PI3Ks.

Amino Acid Sequence↗
PubMed1998

cDNA cloning, expression, subcellular localization, and chromosomal assignment of mammalian aurora homologues, aurora-related kinase (ARK) 1 and 2.

Chromosomal segregation during mitosis as well as meiosis is considered to be regulated by multiple kinases, but the precise mechanism remains largely unknown. A mutation in Drosophila, designated aurora, was identified as a responsible gene for a chromosomal segregation defect and encodes a putative serine-threonine kinase. Here we have identified mammalian aurora homologues, designated aurora-related kinase (ARK) 1 and ARK2. Kinase domains of murine ARK1 and ARK2 showed 61 and 62% identity, respectively, to that of aurora at the amino acid levels, respectively. Cell cycle analysis revealed that the expression of ARK1 was correlated with G2/M phase, while ARK2 was expressed during S and G2/M phases. Immunofluorescence analysis demonstrated that ARK2 was mainly localized to the midbody, while ARK1 has been reported to be localized to the spindle pole during mitosis. Collectively, these results suggest that these two kinases may have distinct roles with different expression timing and subcellular localization during the cell cycle progression. Interspecific backcross mapping revealed that Ark1 is located in a distal region of mouse chromosome 2, while Ark2 is located in a central region of mouse chromosome 11.

3T3 Cells↗
PubMed1998

Genomic structure and chromosomal localization of the mouse LIM domain-binding protein 1 gene, Ldb1.

The LIM domain is a structural motif that is well conserved throughout evolution in a variety of factors known to play important roles in development and cell regulation. Ldb genes encode LIM domain-binding (Ldb) factors. Here we report on the structural organization and chromosomal localization of the mouse Ldb1 gene. It contains at least 10 exons and spans approximately 4 kb of genomic DNA. The transcription initiation site is located 462 bp upstream of the translation initiation codon ATG as determined by 5'-RACE. Sequencing analysis of the 5'-flanking region shows TATA and CCAAT motifs as well as potential binding sites for GATA, CF-1, PEA3, HRE, APRRE, RARE, Myc, and c-Jun. Ldb1 maps to the distal region of mouse chromosome 19 that is syntenic with human chromosome 10q.

Animals↗
PubMed1998

Mouse annexin III cDNA, genetic mapping and evolution.

Mouse annexin III cDNA was characterized from I.M.A.G.E. Consortium (LLNL) expressed sequence tag clones by molecular sequencing, chromosomal mapping and systematic analysis. cDNA sequences extended the known 5' and 3' untranslated regions and confirmed the location of intron 7 with respect to the human gene. The Anx3 locus mapped to the middle of mouse chromosome 5 between Areg and Fgf5. Protein-coding regions were compared with homologous annexins to establish subfamily identity, structural conservation and divergence pattern. Annexin III exhibited low functional constraint against structural change and weak phylogenetic association with known annexins. The rapid, constant divergence of human and rodent annexins III from each other and from other annexin subfamilies was used to estimate gene separation times. Phylogenetic, phenetic and structural data suggested a possible direct or indirect separation of annexin III from XI approximately 317 million years ago.

Amino Acid Sequence↗
PubMed1998

Cloning and characterization of a new type of mouse chemokine.

We report here the identification and characterization of the mouse homologue of a human CX3C chemokine described by F. Bazan et al. (1997, Nature 385, 640-644). Termed fractalkine, this molecule constitutes a fourth or delta chemokine structural type that displays a novel CX3C sequence fingerprint. Distinct from the alpha, beta, or gamma chemokine families, the polypeptide chain of CX3C predicts a 373-amino-acid type I transmembrane glycoprotein with the chemokine domain resting on top of an extended mucin-like stalk. Comparison of the mouse and human protein chains shows a high degree of conservation in all the globular segments with the exception of the stalk portion. The striking identity of an amino acid stretch encompassing a putative juxtamembrane cleavage site suggests the evolutionary conservation of both membrane-bound and processed CX3C forms. Northern analysis reveals the presence of mouse CX3C mRNA in heart, brain, lung, kidney, skeletal muscle, and testis tissues. The mouse CX3C gene was further localized to the central region of chromosome 8 by interspecific backcross mapping; a related locus was detected on chromosome 11. The novel location of this gene from other chemokine gene clusters adds to the notion that CX3C is a fundamentally new class of chemokine.

Amino Acid Sequence↗
PubMed1998

epicardin: A novel basic helix-loop-helix transcription factor gene expressed in epicardium, branchial arch myoblasts, and mesenchyme of developing lung, gut, kidney, and gonads.

We report the cloning, chromosomal localization, and analysis of the expression pattern of epicardin, a member of the basic helix-loop-helix (bHLH) family of transcription factors. Within its bHLH domain, the human and murine epicardin genes were most similar to paraxis, a bHLH gene important for segmentation of embryonic paraxial mesoderm. In situ hybridization studies revealed strong epicardin expression in murine embryos at 9.5 days postcoitum (dpc) in a region of the septum transversum at the base of the heart known as the proepicardial organ. This mesenchymal structure extends villous projections from which epicardial precursor cells emerge and migrate out over the surface of the myocardium. Strong expression was seen in individual migratory cells and clusters at 9.5 dpc and in a continuous epicardial cell layer in more mature hearts. Also from 9.5 dpc, epicardin transcripts were seen in endocardial cushions of the atrioventricular canal and outflow tract, in skeletal myoblasts within branchial arches and in condensing mesenchyme of gut, kidney, urinary tract, gonads, spleen, and lung. Northern analysis showed that expression persisted in mature visceral organs and heart, but was transient in skeletal muscle. The central role played by bHLH factors in pathways for tissue determination in the embryo suggests a function for epicardin in specification of select mesodermal cell populations associated with heart, cranial skeletal muscle, gut, and urogenital system.

Amino Acid Sequence↗
PubMed1998

The genetic origin of mouse annexin VIII.

Mouse annexin VIII cDNA was characterized by DNA sequencing of expressed sequence tag clones, molecular systematic analysis, and genetic linkage mapping to investigate its evolutionary origin. Its subfamily identity, divergence pattern, and nucleotide substitution rate were established by comparison with other annexin cDNA and deduced protein sequences. The known phylogenetic association of annexin VIII in an evolutionary clade with annexins XI, IV, V, and VIa identified these close homologs as potential progenitors or duplication products. Cladistic analysis confirmed the base position of annexin XI and its relationship to annexin IV as a direct duplication product. Although annexin VIII also derived from annexin XI, the evolutionary branching order, gene separation times, and mapping results indicated that it was probably a subsequent duplication product of annexin IV about 300 million years ago. Dates were calibrated against the assumed separation time of 75 Mya for rodents from other mammals, divergence rates were based on comparisons of all available annexin species, and relative rate tests implied individually stable gene clocks for most annexins. Linkage mapping of mouse Anx8 to the centromeric region of Chromosome (Chr) 14 placed it in a more distal homology group from previously mapped Anx7 and Anx11. Despite their synteny, the combined proximity and segregation of these three annexins diminished the likelihood that they were mutual gene duplication products.

Amino Acid Sequence↗