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C Disteche

Publications and source records attributed to C Disteche.

At least 19 recordsLinked to original sources

The human UTY gene encodes a novel HLA-B8-restricted H-Y antigen.

The mammalian Y chromosome encodes male-specific minor histocompatibility (H-Y) Ags that are recognized by female T cells in an MHC-restricted manner. Two human H-Y epitopes presented by HLA-A2 and HLA-B7, respectively, have been identified previously and both are derived from the SMCY gene. We previously isolated CD8+ CTL clones that recognized a male-specific minor histocompatibility Ag presented by HLA-B8. In contrast to the SMCY-encoded H-Y epitopes, the B8/H-Y Ag was not presented by fibroblasts from male donors, suggesting that it was encoded by a novel gene. We now report that the HLA-B8-restricted H-Y epitope is defined by the octameric peptide LPHNHTDL corresponding to aa residues 566-573 of the human UTY protein. Transcription of the UTY gene is detected in a wide range of human tissues, but presentation of the UTY-derived H-Y epitope to CTL by cultured human cells shows significant cell-type specificity. Identification of this CTL-defined H-Y epitope should facilitate analysis of its contribution to graft/host interactions following sex-mismatched organ and bone marrow transplantation.

Amino Acid Sequence↗

Common trisomy mosaicism diagnosed in amniocytes involving chromosomes 13, 18, 20 and 21: karyotype-phenotype correlations.

Karyotype-phenotype correlations of common trisomy mosaicism prenatally diagnosed via amniocentesis was reviewed in 305 new cases from a collaboration of North American cytogenetic laboratories. Abnormal outcome was noted in 10/25 (40%) cases of 47,+13/46, 17/31 (54%) cases of 47,+18/46, 10/152 (6.5%) cases of 47,+20/46, and in 49/97 (50%) cases of 47,+21/46 mosaicism. Risk of abnormal outcome in pregnancies with less than 50% trisomic cells and greater than 50% trisomic cells were: 26% (4/15) versus 60% (6/10) for 47,+13/46, 52% (11/21) versus 75% (6/8) for 47,+18/46, 4.5% (6/132) versus 20% (4/20) 47,+20/46, and 45% (27/60) versus 59% (22/37) for 47,+21/46. Phenotypically normal liveborns were observed with mean trisomic cell lines of 9.3% for 47,+13/46, 8.6% for 47,+18/46, 27% for 47, +20/46, and 17% for 47,+21/46. Cytogenetic confirmation rates were 46% (6/13 cases) for 47,+13/46 mosaicism, 66% (8/12 cases) for 47, +18/46, 10% (10/97 cases) for 47,+20/46, and 44% (24/54 cases) for 47,+21/46. There were higher confirmation rates in pregnancies with abnormal versus normal outcome: 50% versus 44% for 47,+13/46 mosaicism, 100% versus 33% for 47,+18/46, 66% versus 7% for 47, +20/46, and 55% versus 40% for 47,+21/46. Repeat amniocentesis is not helpful in predicting clinical outcome. It may be considered when there is insufficient number of cells or cultures to establish a diagnosis. Fetal blood sampling may have a role in mosaic trisomy 13, 18, and 21 as the risk for abnormal outcome increases with positive confirmation: 1/5 (20%) normal cases versus 5/8 (62%) abnormal cases. High resolution ultrasound examination(s) is recommended for clinical correlation and to facilitate genetic counselling.

Abnormalities, Multiple↗

Identification of ZFR, an ancient and highly conserved murine chromosome-associated zinc finger protein.

In a screen for RNA binding proteins expressed during murine spermatogenesis, we cloned a novel, ancient zinc finger protein possessing a region common to a small class of RNA binding proteins. Zfr (zinc finger RNA binding) encodes a protein of 1052 amino acids with three widely spaced Cys2His2 zinc fingers. Outside of the zinc fingers, ZFR shares a region that is highly conserved between several RNA binding proteins containing copies of the double-stranded RNA binding motif. By northern blotting, Zfr is expressed at highest levels within the testis, ovary and brain. Immunohistochemistry and confocal microscopy were used to show that ZFR is highly expressed during meiosis I in males and females and is chromosome associated. Zfr is also expressed in Sertoli cells in the testis and granulosa cells in the ovary where it is localized to the nucleus. Using fluorescent in situ hybridization we mapped Zfr to chromosome 15 region A. ZFR appears to be an ancient protein, as apparent homologs exist in invertebrates (D. melanogaster) nematodes (C. elegans) and humans (H. sapiens).

Amino Acid Sequence↗

Cloning and characterization of the mouse interleukin enhancer binding factor 3 (Ilf3) homolog in a screen for RNA binding proteins.

In a screen for RNA-binding proteins expressed during murine spermatogenesis, we have identified a cDNA that encodes a protein of 911 amino acids that contains two copies of the double-stranded RNA-binding motif and has 80% identity with human Interleukin Enhancer Binding Factor 3 (ILF3). Linkage and cytogenetic analyses localized the Ilf3 cDNA to a portion of mouse Chr 9, which shows conserved synteny with a region of human Chr 19 where the human ILF3 gene had been previously localized, supporting that we had cloned the murine homolog of ILF3. Northern analysis indicated the Ilf3 gene is ubiquitously expressed in mouse adult tissues with high levels of expression in the brain, thymus, testis, and ovary. Polyclonal antibodies detected multiple protein species in a subset of the tissues expressing Ilf3 RNA. Immunoreactive species are present at high levels in the thymus, testis, ovary, and the spleen to a lesser extent. The high degree of sequence similarity between the mouse ILF3 protein and other dsRNA binding motif-containing proteins suggests a role in RNA metabolism, while the differential expression indicates the mouse ILF3 protein predominantly functions in tissues containing developing lymphocyte and germ cells.

3' Untranslated Regions↗

Cloning, chromosomal mapping, and regulatory properties of the human type 9 adenylyl cyclase (ADCY9).

The type 9 adenylyl cyclase (AC9) is a widely distributed adenylyl cyclase that was originally cloned from a mouse cDNA library. Here we report the cloning, chromosomal mapping, and regulatory properties of human AC9 (HGMW-approved symbol ADCY9). Although the human AC9 sequence shows 86% homology with mouse AC9, divergence at the C2a/C2b junction results in an alternative C2b amino acid sequence. In situ hybridization localized the human AC9 gene to both human and mouse chromosomes 16. AC9 mRNA is present in all tissues examined, with the highest levels found in skeletal muscle, heart, and brain. To characterize the regulatory properties of human AC9 in vivo, the enzyme was expressed in HEK-293 cells. Human AC9 is stimulated by beta-adrenergic receptor activation but is insensitive to forskolin, Ca2+ and somatostatin. In contrast to mouse AC9, the activity of human AC9 is unaffected by inhibitors of calcineurin. These data emphasize the importance of determining the regulatory properties of human adenylyl cyclases.

Adenylyl Cyclase Inhibitors↗

Reconstructing hominid Y evolution: X-homologous block, created by X-Y transposition, was disrupted by Yp inversion through LINE-LINE recombination.

The human X and Y chromosomes share many blocks of similar DNA sequence. We conducted mapping and nucleotide sequencing studies of extensive, multi-megabase homologies between Yp and Xq21, which do not recombine during male meiosis. We confirmed and built upon previous evidence that a Yp inversion had occurred during evolution: a single contiguous segment of Xq21 is homologous to two non-contiguous segments of Yp. We precisely defined and sequenced the inversion breakpoints, obtaining evidence that the inversion was mediated by recombination between LINE-1 elements in otherwise non-homologous regions. This inversion appears to have followed a single transposition of an approximately 4 Mb segment from the X to the Y chromosome. These events jointly account for the present arrangement of Yp-Xq21 homologous sequences. Based on Southern blotting studies of primates and of humans drawn from diverse populations, we conclude that both the X-Y transposition and the subsequent, LINE-mediated Yp inversion occurred after the divergence of hominid and chimp lineages but before the radiation of extant human populations. This evolutionary scenario is consistent with our finding of 99.3 +/- 0.2% nucleotide identity between the X and Y chromosomes within the transposed region, which suggests that the transposition occurred approximately 3-4 million years ago, near the time of emergence of Homo . Comparative sequencing of the entire human X and Y chromosomes may reveal a succession of transpositions, inversions and other rearrangements underlying the complex pattern of sequence similarities between the present-day sex chromosomes. With the possible exception of cubitus valgus, phenotypic features of Turner syndrome are absent in individuals monosomic for Yp-Xq21 homologous sequences, suggesting that most of the critical 'Turner genes' are found elsewhere on the X and Y chromosomes.

Base Sequence↗

Normal function of the transcription factor NFAT1 in wasted mice. Chromosome localization of NFAT1 gene.

NFAT1 (NFATp), a cytosolic component of the nuclear factor of activated T cells (NFAT), is encoded by a single gene which was mapped to mouse chromosome 2 in the vicinity of the wasted (wst) locus. Although wasted mice display a severe immune disorder, they express normal levels of NFAT1 protein. The NFAT1 protein in wasted mice is properly regulated and possesses comparable DNA binding activity as that in their littermate controls. Therefore, the wasted phenotype is not due to a defect in the expression or early regulation of the NFAT1 protein.

Animals↗

The translocation t(8;16)(p11;p13) of acute myeloid leukaemia fuses a putative acetyltransferase to the CREB-binding protein.

The recurrent translocation t(8;16)(p11;p13) is a cytogenetic hallmark for the M4/M5 subtype of acute myeloid leukaemia. Here we identify the breakpoint-associated genes. Positional cloning on chromosome 16 implicates the CREB-binding protein (CBP), a transcriptional adaptor/coactivator protein. At the chromosome 8 breakpoint we identify a novel gene, MOZ, which encodes a 2,004-amino-acid protein characterized by two C4HC3 zinc fingers and a single C2HC zinc finger in conjunction with a putative acetyltransferase signature. In-frame MOZ-CBP fusion transcripts combine the MOZ finger motifs and putative acetyltransferase domain with a largely intact CBP. We suggest that MOZ may represent a chromatin-associated acetyltransferase, and raise the possibility that a dominant MOZ-CBP fusion protein could mediate leukaemogenesis via aberrant chromatin acetylation.

Acetyltransferases↗

Different chromosomal localization of the Clcn4 gene in Mus spretus and C57BL/6J mice.

We report the unprecedented finding of a gene with a different map position in two mouse strains. The Clcn4 gene was found to map to the X chromosome in the wild Mediterrean mouse, Mus spretus but to chromosome 7 in the inbred strain of laboratory mouse C57BL/6J. These data indicate that a recent evolutionary rearrangement occurred on the mouse sex chromosomes, very close to the pseudoautosomal region. Our data provide molecular evidence for a major divergence near the pseudoautosomal region, consistent with the hypothesis that hybrid sterility in these species results from abnormal pairing of sex chromosomes during male meiosis.

Amino Acid Sequence↗

Down syndrome phenotypes: the consequences of chromosomal imbalance.

Down syndrome (DS) is a major cause of mental retardation and congenital heart disease. Besides a characteristic set of facial and physical features, DS is associated with congenital anomalies of the gastrointestinal tract, an increased risk of leukemia, immune system defects, and an Alzheimer-like dementia. Moreover, DS is a model for the study of human aneuploidy. Although usually caused by the presence of an extra chromosome 21, subsets of the phenotypic features of DS may be caused by the duplication of small regions of the chromosome. The physical map of chromosome 21 allows the molecular definition of the regions duplicated in these rare cases of partial trisomy. As a first step in identifying the genes responsible for individual DS features and their pathophysiology, a panel of cell lines derived from 16 such individuals has been established and the molecular break points have been determined using fluorescence in situ hybridization and Southern blot dosage analysis of 32 markers unique to human chromosome 21. Combining this information with detailed clinical evaluations of these patients, we have now constructed a "phenotypic map" that includes 25 features and assigns regions of 2-20 megabases as likely to contain the genes responsible. This study provides evidence for a significant contribution of genes outside the D21S55 region to the DS phenotypes, including the facies, microcephaly, short stature, hypotonia, abnormal dermatoglyphics, and mental retardation. This strongly suggests DS is a contiguous gene syndrome and augurs against a single DS chromosomal region responsible for most of the DS phenotypic features.

Blotting, Southern↗

CD19 maps to a region of conservation between human chromosome 16 and mouse chromosome 7.

CD19 is a B lymphocyte cell surface protein expressed from the earliest stages of B lymphocyte development until their terminal differentiation into plasma cells. In this report the human CD19 gene (hCD19) was localized to band p11.2 on the proximal short arm of chromosome 16 by in situ hybridization to metaphase chromosomes, using hCD19 cDNA as probe. hCD19 gene localization was confirmed by polymerase chain reaction based analysis with hCD19-specific primers, using a panel of human/hamster somatic cell hybrid DNA as templates. The mouse CD19 gene (mCd19) was mapped to bands F3-F4 of chromosome 7 by in situ hybridization to metaphase chromosomes, using a mCD19 cDNA probe. Segregation analysis of nucleotide sequence polymorphisms in interspecific backcross progeny revealed linkage of mCd19 with hemoglobin beta (Hbb), Int-2, and H19, other loci previously mapped to the same region of mouse chromosome 7, confirming the localization of mCd19 to this region. The order of these loci was determined to be centromere--Hbb--mCd19--H19--Int-2--telomere. The genetic distances between the loci examined, calculated from the recombination frequencies, suggested that mCd19 was located centrally between Hbb and H19. This region of mouse chromosome 7 is homologous to the region of human chromosome 16 to which the hCD19 gene maps. Multiple genes with a lymphocyte-related function also map to this conserved region including genes encoding the IL-4 receptor, CD11a, CD11b, CD11c, CD43 (leukosialin), and protein kinase C beta polypeptide.

Animals↗

beta ig-h3: a transforming growth factor-beta-responsive gene encoding a secreted protein that inhibits cell attachment in vitro and suppresses the growth of CHO cells in nude mice.

beta ig-h3 is a novel gene first discovered by differential screening of a cDNA library made from A549 human lung adenocarcinoma cells treated with transforming growth factor-beta 1 (TGF-beta 1). It encodes a 683-amino-acid protein containing a secretory signal sequence and four homologous internal domains. Here we show that treatment of several types of cells, including human melanoma cells, human mammary epithelial cells, human keratinocytes, and human fibroblasts, with TGF-beta resulted in a significant increase in beta ig-h3 RNA. A portion of the beta ig-h3 coding sequence was expressed in bacteria, and antisera against the bacterially produced protein was raised in rabbits. This antisera was used to demonstrate that several cell lines secreted a 68-kD beta IG-H3 protein after treatment with TGF-beta. Transfection of beta IG-H3 expression plasmids into Chinese hamster ovary (CHO) cells led to a marked decrease in the ability of these cells to form tumors in nude mice. The beta IG-H3 protein was purified from media conditioned by recombinant CHO cells, characterized by immunoblotting and protein sequencing and shown to function in an anti-adhesion assay in that it inhibited the attachment of A549, HeLa, and WI-38 cells to plastic in serum-free media. Sequencing of cDNA clones encoding murine beta ig-H3 indicated 90.6% conservation at the amino acid level between the murine and human proteins. Finally, the beta ig-h3 gene was localized to human chromosome 5q31, a region frequently deleted in preleukemic myelodysplasia and leukemia. The corresponding mouse beta ig-h3 gene was mapped to mouse chromosome 13 region B to C1, which confirms a region of conservation on human chromosome 5 and mouse chromosome 13. We suggest that this protein be named p68 beta ig-h3.

Amino Acid Sequence↗

Linkage of the erythroid transcription factor gene (Gf-1) to the proximal region of the X chromosome of mice.

We have used a cDNA probe for mouse Gf-1 gene that encodes the erythroid cell transcription factor to identify genetic variation in genomic DNA between Mus species. The segregation of Gf-1 DNA variation was analyzed in Mus species crosses that have been previously typed for the segregation of more than 30 genes spanning 80 cM of the mouse X chromosome from the centromere to the border of the X-Y pairing region. We identified a single X chromosome locus in the mouse, Gf-1, and an analysis of recombinants from 203 backcross progeny mapped Gf-1 to the proximal portion of the chromosome, coincident with the Cybb locus and proximal to Otc gene locus. A gene order of centromere, DXWas70, Cybb/Gf-1, Otc, Timp was established for the mouse X chromosome, which is in agreement with the map position observed on the human X chromosome.

Animals↗