Biomedical subjects

C M Disteche

Publications and source records attributed to C M Disteche.

At least 91 records · Page 5Linked to original sources

PubMed1992

Expression of the receptor-linked protein tyrosine phosphatase LAR: proteolytic cleavage and shedding of the CAM-like extracellular region.

The human transmembrane molecule LAR is a protein tyrosine phosphatase (PTPase) with a cell adhesion molecule-like extracellular receptor region. The structure of LAR hinted at its involvement in the regulation of tyrosine phosphorylation through cell-cell or cell-matrix interactions. We show here that LAR is expressed on the cell surface as a complex of two non-covalently associated subunits derived from a proprotein. The LAR E-subunit contains the cell adhesion molecule-like receptor region, while the LAR P-subunit contains a short segment of the extracellular region, the transmembrane peptide and the cytoplasmic PTPase domains. Proprotein processing occurs intracellularly. Analysis of LAR mutants suggested that cleavage occurs in the LAR extracellular region at a paired basic amino acid site by a subtilisin-like endoprotease. A single amino acid substitution at this site blocked LAR proprotein cleavage. The LAR E-subunit is shed during cell growth, suggesting that LAR receptor shedding may be a mechanism for regulating PTPase function. The use of immunohistochemistry techniques on human tissues demonstrated the expression of LAR by various cell lineages, including epithelial cells, smooth muscle cells and cardiac myocytes. The LAR gene is mapped to chromosome 1, region p32-33, which contains candidate tumor suppressor genes.

Amino Acid Sequence↗

PubMed1992

Mapping and expression of the ubiquitin-activating enzyme E1 (Ube1) gene in the mouse.

The nucleotide sequence of the human cDNA encoding ubiquitin-activating enzyme E1 is more than 99% identical with the human A1S9T cDNA, a gene that has been shown to complement the temperature-sensitive mutant mouse cell line, tsA1S9. The amino acid sequences of the proteins encoded by these two cDNA sequences are identical, and both cDNAs were previously shown to be located in the same region of the human X chromosome; thus, ubiquitin-activating enzyme E1 and A1S9T appear to be the same gene, designated UBE1. By in situ hybridization to metaphase chromosomes from male mice and by Southern blot analysis of male and female mouse DNA, we show that, in the mouse, a human UBE1 cDNA probe identified both X- and Y-linked loci. Ube1 is located at band A2 of the mouse X Chromosome (Chr) and Ube2 on the short arm of the Y Chr. This is in contrast to the situation in the human, where there is no evidence for Y-linked sequences related to UBE1. Mapping of the Ube1 gene in interspecific backcrosses between Mus spretus and C57BL/6 shows that the Ube1 locus maps close to Timp, in a conserved region of the mouse and human X Chrs that include Otc, Cybb, Syn1, Timp, and Araf. Expression of Ube1 on the inactive X Chr was examined to determine whether this gene is subject to X-Chr inactivation in the mouse, as there is previous evidence that the human UBE1 gene escapes, at least partially, X inactivation. Sequencing of reverse transcriptase polymerase chain reaction (RT-PCR) products from M. spretus, C57BL/6J, and T(X;16)16H x M. spretus F1 female mice indicates that the mouse Ube1 gene is subject to X-Chr inactivation in vivo. This represents a new example of differences between the sex chromosomes of mouse and human.

Animals↗

PubMed1992

Chromosomal mapping of the human annexin IV (ANX4) gene.

Annexin IV (placental anticoagulant protein II) is a member of the annexin or lipocortin family of calcium-dependent phospholipid-binding proteins. A cDNA for human annexin IV was isolated from a placental library that is 675 bases longer in the 3' untranslated region than previously reported, indicating the existence of alternative mRNA processing for this gene. Genomic Southern blotting with a cDNA probe indicated a gene size of 18-56 kb. Primers developed for polymerase chain reaction (PCR) allowed amplification of a 1.6-kb portion of the ANX4 gene. DNA sequence analysis showed that this PCR product contained a single intron with exon-intron boundaries in exactly the same position as in the mouse annexin I and annexin II genes. PCR analysis of a somatic cell hybrid panel mapped the ANX4 gene to chromosome 2, and in situ hybridization with a cDNA probe showed a unique locus for ANX4 at 2p13. This study provides further evidence that genes for the annexins are dispersed throughout the genome but are similar in size and exon-intron organization.

Amino Acid Sequence↗

PubMed1992

Thrombospondin II: partial cDNA sequence, chromosome location, and expression of a second member of the thrombospondin gene family in humans.

A novel form of human thrombospondin was identified during the screening of a human fibroblast cDNA library. We report the cDNA sequence for 1.8 kb of the 3' end of the cDNA, plus an additional 937 bp of 3'-untranslated sequence. The translated sequence reveals a high degree of similarity to thrombospondin I. The homology ranges from 56 to 80% for different regions within the two proteins. The repeating segments of amino acid sequence identified in thrombospondin I were found to be conserved in thrombospondin II. The new form of thrombospondin hybridizes to a 7.5-kb message by Northern analysis. The THBS2 gene is located at the distal long arm of chromosome 6 at 6q27. The gene is transcribed in fibroblasts, smooth muscle cells, and an osteosarcoma cell line, at levels somewhat lower than that of thrombospondin I. Umbilical vein endothelial cells do not transcribe thrombospondin II under the conditions of this study. These findings suggest that previous studies of thrombospondin function need to be reassessed to identify the functions specific to each molecule.

Amino Acid Sequence↗

PubMed1992

The human pseudoautosomal GM-CSF receptor alpha subunit gene is autosomal in mouse.

The gene encoding the granulocyte macrophage colony stimulating factor receptor alpha subunit (CSF2RA) has previously been mapped to the pseudoautosomal region of the human sex chromosomes. In contrast, we report that the murine locus, Csf2ra, maps to an autosome in the laboratory mouse. By in situ hybridization and genetic mapping, Csf2ra maps at telomeric band D2 of mouse chromosome 19. This first instance of a pseudoautosomal locus in human being autosomal in mouse, indicates incomplete conservation between the human and mouse X chromosomes and suggests that the genetic content of the pseudoautosomal region may differ between species of eutherian mammals due to chromosomal rearrangements.

Animals↗

PubMed1992

Down syndrome: molecular mapping of the congenital heart disease and duodenal stenosis.

Down syndrome (DS) is a major cause of congenital heart and gut disease and mental retardation. DS individuals also have characteristic facies, hands, and dermatoglyphics, in addition to abnormalities of the immune system, an increased risk of leukemia, and an Alzheimer-like dementia. Although their molecular basis is unknown, recent work on patients with DS and partial duplications of chromosome 21 has suggested small chromosomal regions located in band q22 that are likely to contain the genes for some of these features. We now extend these analyses to define molecular markers for the congenital heart disease, the duodenal stenosis, and an "overlap" region for the facial and some of the skeletal features. We report the clinical, cytogenetic, and molecular analysis of two patients. The first is DUP21JS, who carries both a partial duplication of chromosome 21, including the region 21q21.1-q22.13, or proximal q22.2, and DS features including duodenal stenosis. Using quantitative Southern blot dosage analysis and 15 DNA sequences unique to chromosome 21, we have defined the molecular extent of the duplication. This includes the region defined by DNA sequences for APP (amyloid precursor protein), SOD1 (CuZn superoxide dismutase), D21S47, SF57, D21S17, D21S55, D21S3, and D21S15 and excludes the regions defined by DNA sequences for D21S16, D21S46, D21S1, D21S19, BCE I (breast cancer estrogen-inducible gene), D21S39, and D21S44. Using similar techniques, we have also defined the region duplicated in the second case occurring in a family carrying a translocation associated with DS and congenital heart disease. This region includes DNA sequences for D21S55 and D21S3 and excludes DNA sequences for D21S47 and D21S17.(ABSTRACT TRUNCATED AT 250 WORDS)

Blotting, Southern↗

PubMed1992

Mapping of MAX to human chromosome 14 and mouse chromosome 12 by in situ hybridization.

The protein encoded by the MAX gene is a member of the class of basic region-helix-loop-helix-zipper proteins and has been demonstrated to associate with N-, L-, and c-Myc proteins both in vitro and in vivo. Heterodimers formed between c-Myc and Max proteins have been shown to possess sequence-specific DNA-binding activity. Here we report the mapping of the MAX gene to a single region on human chromosome 14 (bands q22-q24) and to mouse chromosome 12 (region D). Chromosome abnormalities linked to several neoplasms have been previously associated with this region on human chromosome 14. The mapping results also confirm a region of homology between human chromosome 14q22-24 and mouse chromosome 12 region D.

Animals↗

PubMed1991

Duplication (6q) syndrome diagnosed in utero.

We report on a case of partial duplication 6q detected ultrasonographically. The clinical picture noted in utero is consistent with the adult phenotype previously reported in the literature.

Abnormalities, Multiple↗

PubMed1991

Cloning and primary structure of a human islet isoform of glutamic acid decarboxylase from chromosome 10.

Glutamic acid decarboxylase (GAD; glutamate decarboxylase, L-glutamate 1-carboxy-lyase, EC 4.1.1.15), which catalyzes formation of gamma-aminobutyric acid from L-glutamic acid, is detectable in different isoforms with distinct electrophoretic and kinetic characteristics. GAD has also been implicated as an autoantigen in the vastly differing autoimmune disease stiff-man syndrome and insulin-dependent diabetes mellitus. Despite the differing GAD isoforms, only one type of GAD cDNA (GAD-1), localized to a syntenic region of chromosome 2, has been isolated from rat, mouse, and cat. Using sequence information from GAD-1 to screen a human pancreatic islet cDNA library, we describe the isolation of an additional GAD cDNA (GAD-2), which was mapped to the short arm of human chromosome 10. Genomic Southern blotting with GAD-2 demonstrated a hybridization pattern different from that detected by GAD-1. GAD-2 recognizes a 5.6-kilobase transcript in both islets and brain, in contrast to GAD-1, which detects a 3.7-kilobase transcript in brain only. The deduced 585-amino acid sequence coded for by GAD-2 shows less than 65% identity to previously published, highly conserved GAD-1 brain sequences, which show greater than 96% deduced amino acid sequence homology among the three species. The function of this additional islet GAD isoform and its importance as an autoantigen in insulin-dependent diabetes remain to be determined.

Amino Acid Sequence↗

PubMed1991

A second thrombospondin gene in the mouse is similar in organization to thrombospondin 1 but does not respond to serum.

A second, expressed thrombospondin (TSP) gene, Thbs2, has been identified in the mouse. The exon/intron organization of Thbs2 is highly conserved in comparison with Thbs1 in that exon size and the pattern of interruption of the reading frame by introns are preserved, but there is a marked divergence in coding sequence, primarily in the first 7 exons. On the other hand, the DNA and translated amino acid sequences of exons coding for the type I, II, and III repeats in the two TSPs are far better conserved. Thbs2 is located on chromosome 17, band A3, whereas Thbs1 was found on chromosome 2, band F. In marked contrast to Thbs1, the Thbs2 gene is not induced by serum in NIH 3T3 cells; promoter sequences in the two genes are also very different. It is therefore likely that the two TSPs perform related but distinct functions.

Animals↗

PubMed1991

Inactivation of the Zfx gene on the mouse X chromosome.

ZFX, an X chromosome-linked gene encoding a zinc-finger protein, has previously been shown to escape X inactivation in humans. Here we report studies of the inactivation status of the homolog, Zfx, on the mouse X chromosome. We took advantage of both the preferential inactivation of the normal X chromosome in females carrying the T(X;16)16H translocation and the high degree of nucleotide sequence variation between the laboratory strain of mouse [corrected] and Mus spretus genomes. An EcoRV restriction fragment difference between laboratory strain of mouse [corrected] and M. spretus was detected after amplification of Zfx transcripts using the reverse transcription-polymerase chain reaction. Using this allelic variation, we assessed expression of the two Zfx genes in females carrying the T(X;16)16H translocation (from laboratory strain of mouse [corrected]) and an intact X chromosome (from M. spretus). Such females exhibit Zfx transcription from the active laboratory strain of mouse [corrected] chromosome but not from the inactive M. spretus chromosome. These results indicate that the mouse Zfx gene is subject to X inactivation.

Animals↗

PubMed1991

Inactivation of the Rps4 gene on the mouse X chromosome.

The human RPS4X and RPS4Y genes, located on the X and Y chromosomes, appear to encode isoforms of ribosomal protein S4. Haploinsufficiency of these genes may contribute to the human phenotype known as Turner syndrome. Although RPS4X maps near the X-inactivation center, the gene is expressed on inactive human X chromosomes. We cloned Rps4, the mouse homolog of RPS4X. Exploiting allelic variation in Rps4, we examined transcription of the gene from active and inactive mouse X chromosomes in vivo, in female mice carrying an X-autosome translocation. We report that mouse Rps4, unlike human RPS4X, is subject to X inactivation. This finding may explain, at least in part, why the phenotypic consequences of X monosomy are less severe in mice than in humans.

Alleles↗

PubMed1991

Regional assignment of the human acid sphingomyelinase gene (SMPD1) by PCR analysis of somatic cell hybrids and in situ hybridization to 11p15.1----p15.4.

Human acid sphingomyelinase (SMPD1) is the lysosomal phosphodiesterase that cleaves sphingomyelin to ceramide and phosphocholine. The deficient activity of SMPD1 is the enzymatic defect in Types A and B Niemann-Pick disease. Previously, the gene encoding human SMPD1 was assigned to chromosome 17 by the differential thermostability of human and hamster SMPD1 in somatic cell hybrids. The recent isolation of the human SMPD1 cDNA (L. E. Quintern, E. H. Schuchman, O. Levran, M. Suchi, K. Ferlinz, H. Reinke, K. Sandhoff, and R. J. Desnick, 1989, EMBO J. 8: 2469-2473) permitted the mapping of this gene by molecular techniques. Oligonucleotide primers were synthesized to PCR amplify the human, but not murine, SMPD1 sequences in man-mouse somatic cell hybrids. In a panel of 15 hybrid cell lines, amplification of the human SMPD1 sequence was 100% concordant with the presence of human chromosome 11. For each of the other human chromosomes there were at least 6 discordant hybrid lines. Further analysis of somatic cell hybrids containing only chromosome 11 or chromosome 11 rearrangements localized the human SMPD1 gene to the region 11p15.1----p15.4. To provide an independent regional gene assignment, in situ hybridization was performed using the radiolabeled human SMPD1 cDNA. In the 58 metaphase cells examined, 34% of the 122 hybridization sites scored were located in the distal end of chromosome 11 with the major peak of hybridization at band 11p15. The absence of any other in situ hybridization site indicated the absence of pseudogenes or homologous sequences elsewhere in the genome. In contrast to the previous provisional localization to chromosome 17, these results assign a single locus for human SMPD1 to 11p15.1----p15.4.

Animals↗

PubMed1991

Chromosomal localization of the human annexin III (ANX3) gene.

The annexins or lipocortins are a new family of calcium-dependent phospholipid-binding proteins. Annexin III has been previously identified as inositol 1,2-cyclic phosphate 2-phosphohydrolase (EC 3.1.4.36), an enzyme of inositol phosphate metabolism, and also as placental anticoagulant protein III, lipocortin III, calcimedin 35-alpha, and an abundant neutrophil cytoplasmic protein. In this study, the gene (ANX3) encoding annexin III was localized to human chromosome 4 at band q21 (q13-q22) by (1) polymerase chain reaction analysis of a human-rodent hybrid cell panel, confirmed by genomic Southern blot analysis of the same panel with a cDNA probe and (2) in situ hybridization with a cDNA probe.

Animals↗

PubMed1991

Physical mapping of the genes for three components of the mouse DNA replication complex: polymerase alpha to the X chromosome, primase p49 subunit to chromosome 10, and primase p58 subunit to chromosome 1.

DNA polymerase alpha and primase are two key enzymatic components of the eukaryotic DNA replication complex. In situ hybridization of cloned cDNAs for mouse DNA polymerase alpha and for the two subunits of mouse primase has been utilized to physically map these genes in the mouse genome. The DNA polymerase alpha gene (Pola) was mapped to the mouse X chromosome in region C-D. The gene encoding the p58 subunit of primase (Prim2) was located to mouse chromosome 1 in region A5-B and the p49 subunit gene (Prim1) was found to be on mouse chromosome 10 in the distal part of band D that is close to the telomere. Current knowledge of mouse and human conserved chromosomal regions along with the findings presented here lead to predictions of where the genes for the DNA primase subunits may be found in the human genome: the p58 subunit gene may be on human chromosome 2 and the p49 subunit gene on human chromosome 12. The mapping of Pola to region C-D of the mouse X chromosome adds a new marker in a conserved region between the mouse X chromosome and region Xp21-22.1 of the human X chromosome.

Animals↗

PubMed1991

Linkage of amelogenin (Amel) to the distal portion of the mouse X chromosome.

Amelogenins are hydrophobic, proline-rich proteins that are the primary biosynthetic products of ameloblasts. These cells are responsible for the formation of tooth enamel, and amelogenins play an important role in the process of biomineralization. A cDNA, corresponding to the mouse 26-kDa amelogenin, has been molecularly cloned and sequenced. Southern blot analysis of genomic DNA from the mouse using this cDNA as a probe indicates that there is only one mouse amelogenin (Amel) gene. This paper describes restriction site variation for the Amel gene that we have identified between C57BL/6 and M. spretus and the segregation of that variation as an X-chromosome gene. The position of the amelogenin locus (Amel) relative to the loci for alpha-galactosidase (Ags), proteolipoprotein (Plp), and the random genomic probe DXWas31 has been determined. Amel is established as: (1) the most distal locus in the genetic map of the mouse X chromosome, (2) lying proximal to the X:Y pairing region, and (3) being restricted to the mouse X chromosome.

Amelogenin↗

PubMed1991

Chromosomal localization of the human gene for annexin V (placental anticoagulant protein I) to 4q26----q28.

Annexin V is a member of a new family of calcium-dependent phospholipid-binding proteins. It has been previously isolated as placental anticoagulant protein I, inhibitor of blood coagulation, vascular anticoagulant-alpha, endonexin II, lipocortin V, placental protein 4, and anchorin CII. The human gene encoding annexin V (ANX5) was localized to 4q26----q28 by in situ hybridization with a cDNA probe and polymerase chain-reaction (PCR) analysis of a human x hamster hybrid cell panel. The regional localization to 4q26----q28 was supported by Southern-blot analysis of a human cell line with a deletion in 4q23----q27. This localization overlaps but differs slightly from the previous assignment of ANX5 to 4q28----q32. Digestion with PvuII and TaqI identified polymorphisms at the ANX5 locus; the PvuII polymorphism could also be detected by PCR analysis.

Animals↗

PubMed1991

Pericentric inversion of the X chromosome: presentation of a case and review of the literature.

A large pericentric inversion of the X chromosome [inv(X)(p22.31q26.3)] was found to be transmitted in four generations through phenotypically normal males and females. In one female carrier, the inv(X) was late replicating in 70% of lymphocytes and 46% of skin fibroblasts. Steroid sulfatase (STS), an enzyme which normally escapes inactivation has been located to Xp22.32 and, in our case, has been moved to an aberrant position. We have assayed its activity in clones with the inv(X) inactive or the normal X inactive and found no significant differences. Thus, the STS locus escaped X inactivation in both the normal and the inverted X chromosomes. A review of the literature shows that almost half of the breakpoints on the short arm are found at region p22 and we propose that low-copy repetitive DNA segments along the X chromosome are responsible for non-homologous pairing and production of inversions.

Amniocentesis↗