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Biomedical subjects

M G Mattei

Publications and source records attributed to M G Mattei.

At least 307 records · Page 17Linked to original sources
PubMed1989

The human alpha 2(XI) collagen (COL11A2) chain. Molecular cloning of cDNA and genomic DNA reveals characteristics of a fibrillar collagen with differences in genomic organization.

We have isolated three overlapping cDNA clones encoding the pro alpha 2(XI) collagen chain from a human chondrocyte cDNA library. Together, the cDNAs code for 257 uninterrupted Gly-X-Y triplets (almost 80% of the triple helical domain) and about 200 amino acid residues of the carboxyl telopeptide and carboxyl propeptide. The identification of the clones as pro alpha 2(XI) cDNAs was based on the complete identity between the amino acid sequences of three tryptic peptides derived from human alpha 2(XI) collagen and the cDNA-derived sequence. We have also sequenced six exons within a human genomic alpha 2(XI) cosmid clone. This sequence shows that although type XI collagen belongs to the fibril-forming class of collagens, there are substantial differences in exon sizes at the 3' end of the gene when comparing the alpha 2(XI) gene with those of human types I, II, and III collagens. Finally, pro alpha 2(XI) cDNA has been used as a probe to determine the location of the gene by in situ hybridization of chromosome spreads. The results demonstrate that the gene is located close to the region p212 on chromosome 6. Northern blot analysis shows that the gene is expressed in cartilage but not in adult liver, skin, and tendon.

Amino Acid Sequence↗
PubMed1989

Molecular cloning of rat and human type IX collagen cDNA and localization of the alpha 1(IX) gene on the human chromosome 6.

Type IX collagen is found in hyaline cartilage, where it is associated with type II collagen in quarter-staggered collagen fibrils. Chicken type IX collagen has been extensively characterized and shown to contain molecules with three triple-helical domains, interspersed with non-triple-helical sequences. The molecule contains three, genetically distinct, subunits and one of these subunits carries a covalently bound glycosaminoglycan side chain. In the present report, we describe for the first time the primary structure of mammalian type IX collagen chains, based on cloning and sequencing of cDNA from rat and human cDNA libraries. The results suggest that mammalian alpha 1(IX) chains have the same multi-domain structure as the avian protein. We also demonstrate, by in situ hybridization of chromosome spreads, that the human alpha 1(IX) collagen gene is located on the long arm of chromosome 6. The cloning of human type IX collagen cDNA provides a probe for molecular studies of human chondrodysplasias that may involve abnormalities in this extracellular collagen-proteoglycan.

Amino Acid Sequence↗
PubMed1989

Novel structures CTLA-2 alpha and CTLA-2 beta expressed in mouse activated T cells and mast cells and homologous to cysteine proteinase proregions.

Differential screening of a subtracted cDNA library led to the detection of two distinct but homologous mouse cDNA, called CTLA-2 alpha and CTLA-2 beta. The corresponding transcripts have a tissue distribution restricted to T lymphocytes, where they are inducible upon activation, and to mast cells. The open-frame regions of both cDNA encode proteins homologous to cysteine proteinase precursors, remarkably, however, only to the proregion of these. The ctla-2 alpha and ctla-2 beta genes both map to the C1 band of mouse chromosome 13. Sequence comparisons suggest that the proregion of an ancestor proteinase gene evolved to the ctla-2 genes by successive duplications, first to autonomy, then to amplification. These results raise the question of the possible role of cysteine proteinase proregions, of cysteine proteinases themselves and of inhibitors thereof in activated T lymphocytes; from a different point of view, they also show that some protease proregions may have evolved as autonomous modules.

Amino Acid Sequence↗
PubMed1989

Study of a family with a fragile site of the X chromosome at Xq27-28 without mental retardation.

The fragile site Xq27-28 was observed in several individuals of a large family. It is expressed at a high frequency among the carrier females, even as adults, and in one clinically normal male. None of the members of this family is affected with the mental retardation normally linked to this fragile site. Cytogenetic and flanking DNA marker polymorphism studies suggest a possible dissociation between the fragile site and clinical expression of the disease.

Adult↗
PubMed1989

Chromosomal localization of human aspartate aminotransferase genes by in situ hybridization.

The localization of the human genes for cytosolic and mitochondrial aspartate aminotransferase (AspAT) has been determined by chromosomal in situ hybridization with specific human cDNA probes previously characterized in our laboratory. The cytosolic AspAT gene is localized on chromosome 10 at the interface of bands q241-q251. Mitochondrial AspAT is characterized by a multigene family located on chromosomes 12 (p131-p132), 16 (q21), and 1 (p32-p33 and q25-q31). Genomic DNA from ten blood donors was digested by ten restriction enzymes, and Southern blots were hybridized with the two specific probes. Restriction fragment length polymorphism was revealed in only one case for cytosolic AspAT, with PvuII, while no polymorphism for mitochondrial AspAT was found.

Aspartate Aminotransferases↗
PubMed1989

Cloning and sequence of a secretory protein induced by growth factors in mouse fibroblasts.

From a collection of 80 cDNAs representing genes that are induced by serum growth factors in quiescent mouse fibroblasts we have characterized a clone, N51, and demonstrated that it codes for a precursor of a secretory protein. N51 mRNA is rapidly induced by serum, including in the presence of cycloheximide, demonstrating that its induction does not require de novo protein synthesis. The mRNA has a short half-life of approximately 10-15 min and is dramatically prolonged in the presence of protein synthesis inhibitors. Purified growth factors such as platelet-derived growth factor and bombesin are strong inducers of N51 expression. However, epidermal growth factor, fibroblast growth factor, and the tumor promoter tetradecanoyl phorbol acetate have a negligible effect. Transcriptional analysis demonstrates that the increase in N51 mRNA levels after serum stimulation is in part due to the activation of gene transcription.

Amino Acid Sequence↗
PubMed1989

In situ hybridization and pulsed-field gel analysis define two major minisatellite loci: 1q23 for minisatellite 33.6 and 7q35-q36 for minisatellite 33.15.

The two classical minisatellite probes, 33.6 and 33.15, were used for in situ hybridization to human metaphase chromosomes. Surprisingly, a single major hybridization peak was observed with each probe, respectively at 1q23 for 33.6 and 7q35-q36 for 33.15. Hybridization to human DNA cleaved with "rare-cutter" enzymes and fractionated on pulsed-field gels also showed a fairly simple, largely monomorphic pattern which allows chromosomal assignment using somatic cell hybrids. Differences in hybridization stringency and degree of resolution account for most of the discrepancy between these results and the accepted view of minisatellites, i.e., a large number of unlinked loci spread over the genome. Our results nevertheless indicate the existence of particularly large and homologous loci on a particular chromosome for each of these probes.

Blotting, Southern↗
PubMed1989

Human laminin A chain (LAMA) gene: chromosomal mapping to locus 18p11.3.

Laminin, an integral component of basement membranes, consists of three subunit polypeptides, A, B1, and B2 chains. We have recently isolated cDNAs corresponding to human laminin A chain. These cDNAs were utilized for chromosomal in situ hybridizations to establish the genomic location of the laminin A chain gene. Metaphase chromosomes of PHA-stimulated human peripheral blood leukocytes were examined by in situ hybridization with 3H-labeled cDNAs, and the chromosomes were identified by R-banding (fluorochrome-photolysis-Giemsa method). The results indicated that the human laminin A chain is at locus 18p11.3. Since human laminin B1 and B2 chain genes have been previously mapped to chromosomes 7 and 1, respectively, the results indicate that genes encoding human laminin chains reside in separate chromosomes.

Blotting, Southern↗
PubMed1989

Chromosomal localization of the mouse gene coding for vimentin.

The chromosomal location of the mouse gene coding for vimentin, one of the intermediate filament subunits, was determined by in situ hybridization using specific H3-labelled DNA probes. There is only one copy of the vimentin gene and it is located on chromosome 2 region A2.

Animals↗
PubMed1989

Characterization of cDNAs encoding human leukosialin and localization of the leukosialin gene to chromosome 16.

We describe the isolation and characterization of cDNA clones encoding human leukosialin, a major sialoglycoprotein of human leukocytes. Leukosialin is very closely related or identical to the sialophorin molecule, which is involved in T-cell proliferation and whose expression is altered in Wiskott-Aldrich syndrome (WAS), an X chromosome-linked immunodeficiency disease. Using a rabbit anti-serum to leukosialin, a cDNA clone was isolated from a lambda gt11 cDNA library constructed from human peripheral blood cells. This lambda gt11 clone was used to isolate longer cDNA clones that correspond to the entire coding sequence of leukosialin. DNA sequence analysis reveals three domains in the predicted mature protein. The extracellular domain is enriched for Ser, Thr, and Pro and contains four contiguous 18-amino acid repeats. The transmembrane and intracellular domains of the human leukosialin molecule are highly homologous to the rat W3/13 molecule. RNA gel blot analysis reveals two polyadenylylated species of 2.3 and 8 kilobases. Southern blot analysis suggests that human leukosialin is a single-copy gene. Analysis of monochromosomal cell hybrids indicates that the leukosialin gene is not X chromosome linked and in situ hybridization shows leukosialin is located on chromosome 16. These findings demonstrate that the primary mutation in WAS is not a defect in the structural gene for leukosialin.

Amino Acid Sequence↗
PubMed1989

The mouse neuronal cell surface protein F3: a phosphatidylinositol-anchored member of the immunoglobulin superfamily related to chicken contactin.

Several members of the Ig superfamily are expressed on neural cells where they participate in surface interactions between cell bodies and processes. Their Ig domains are more closely related to each other than to Ig variable and constant domains and have been grouped into the C2 set. Here, we report the cloning and characterization of another member of this group, the mouse neuronal cell surface antigen F3. The F3 cDNA sequence contains an open reading frame that could encode a 1,020-amino acid protein consisting of a signal sequence, six Ig-like domains of the C2 type, a long premembrane region containing two segments that exhibit sequence similarity to fibronectin type III repeats and a moderately hydrophobic COOH-terminal sequence. The protein does not contain a typical transmembrane segment but appears to be attached to the membrane by a phosphatidylinositol anchor. Antibodies against the F3 protein recognize a prominent 135-kD protein in mouse brain. In fetal brain cultures, they stain the neuronal cell surface and, in cultures maintained in chemically defined medium, most prominently neurites and neurite bundles. The mouse f3 gene maps to band F of chromosome 15. The gene transcripts detected in the brain by F3 cDNA probes are developmentally regulated, the highest amounts being expressed between 1 and 2 wk after birth. The F3 nucleotide and deduced amino acid sequence show striking similarity to the recently published sequence of the chicken neuronal cell surface protein contactin. However, there are important differences between the two molecules. In contrast to F3, contactin has a transmembrane and a cytoplasmic domain. Whereas contactin is insoluble in nonionic detergent and is tightly associated with the cytoskeleton, about equal amounts of F3 distribute between buffer-soluble, nonionic detergent-soluble, and detergent-insoluble fractions. Among other neural cell surface proteins, F3 most resembles the neuronal cell adhesion protein L1, with 25% amino acid identity between their extracellular domains. Based on its structural similarity with known cell adhesion proteins of nervous tissue and with L1 in particular, we propose that F3 mediates cell surface interactions during nervous system development.

Amino Acid Sequence↗
PubMed1989

Human nidogen: cDNA cloning, cellular expression, and mapping of the gene to chromosome Iq43.

A human placental lambda gt11 expression cDNA library was screened for nidogen cDNAs by hybridizations with a heterologous mouse nidogen cDNA. A total of four positive overlapping clones were identified, and the sizes of the inserts were shown to vary from 0.8 to 2.8 kb. Nucleotide sequencing of the human cDNAs revealed that the largest clone, cHPN-16, contained both a 5' open reading frame encoding 582 amino acids and a 3' untranslated region of 1,063 nucleotides. Comparison of human cDNA sequences with mouse nidogen sequences revealed 84% identity on the nucleotide level and 88% identity with the deduced amino acid sequence. The deduced amino acid sequence of the human cDNAs revealed the presence of cysteine-rich epidermal growth factor-like repeats and the sequence Arg-Gly-Asp (RGD), a potential cell binding site, two features previously identified in mouse nidogen. The sequence Asn-Pro-Ser, a consensus sequence for N-linked glycosylation, was also noted. The newly isolated human cDNAs were utilized to analyze the expression of the nidogen gene by cultured human cells. Northern hybridizations revealed a single mRNA transcript of approximately 6.0 kb in human skin fibroblast and in HT 1080 fibrosarcoma cell cultures. However, the human choriocarcinoma cell line JEG-3, which expressed laminin genes, did not contain detectable levels of nidogen mRNAs. Quantitation of the relative nidogen mRNA abundance in HT 1080 fibrosarcoma cells indicated that nidogen mRNA levels were approximately the same as those for the laminin B2 chain. Finally, one of the nidogen cDNAs was used to map the nidogen gene onto locus q43 of chromosome 1.

Amino Acid Sequence↗
PubMed1989

Neurological disorder in transgenic mice that express the large T antigen of polyoma virus in the nervous system.

Among a series of 44 transgenic families established after microinjection into fertilized eggs of a plasmid DNA where the structural gene for the large T antigen of polyoma virus is located downstream from the viral early promoter-enhancer region, one family with a hereditary neurological disorder was observed. At about three weeks of age, these animals developed a syndrome of constant tremor with recurrent seizures. Histological and ultra-structural examination revealed extensive dysmyelination in the white matter of the brain stem, cerebellum and spinal cord, as well as of peripheral nerves. This phenotype is reminiscent of that of the mouse "twitcher" (twi) mutant and of the human hereditary leukodystrophies. Expression of the viral sequences, assayed by Northern analysis and immunolabeling of T antigen, occurred predominantly in cells of the central nervous system. Integration of the transgene was mapped by in situ hybridization on metaphasic plaques in region B-C1 of chromosome 12 (where the twi locus was previously localized). Long-term cultures of cells with neural characteristics could be established readily from the brain of the transgenic mice.

Animals↗
PubMed1989

The putative oncogene Spi-1: murine chromosomal localization and transcriptional activation in murine acute erythroleukemias.

We have shown previously that spleen focus forming virus integration near the Spi-1 putative oncogene is observed in 95% of erythroid Friend tumors (Moreau-Gachelin et al., 1988). Here we describe how the proviral insertion in the Spi-1 domain is associated with the enhanced transcription of a 1.4 kb mRNA normally expressed at a low level in normal cells. The gene is localized on murine chromosome 2, band E3. The structure of the Spi-1 gene was determined by sequencing genomic and cDNA clones. The gene has an open reading frame encoding a protein of 218 amino acids, extending over five exons. Proviruses always integrate outside, upstream and in the opposite orientation of the protein-encoding domain. This suggests that SFFV integration activates the expression of Spi-2 gene that may contribute to the erythroleukemic process.

Amino Acid Sequence↗