Recently, interest has focused on the human gene encoding the putative protein homologous to VAT-1, the major protein of the synaptic vesicles of the electric organ of the Pacific electric ray Torpedo californica, after it has been localized on chromosome locus 17q21 in a region encompassing the breast cancer gene BRCA1. Chromosomal instability in this region is implicated in inherited predisposition for breast and ovarian cancer. Here we describe isolation and biochemical characterization of a mammalian 48 kDa protein homologous to the VAT-1 protein of Torpedo californica. This VAT-1 homolog was isolated from a murine breast cancer cell line (Ehrlich ascites tumor) and identified by sequencing of cleavage peptides. The isolated VAT-1 homolog protein displays an ATPase activity and exists in two isoforms with isoelectric points of 5.7 and 5.8. cDNA was prepared from Ehrlich ascites tumor cells, and the murine VAT-1 homolog sequence was amplified by polymerase chain reaction and partially sequenced. The known part of the murine and the human translated sequences share 97% identity. By Northern blots, the size of the VAT-1 homolog mRNA in both murine and human (T47D) breast cancer cells was determined to be 2.8 kb. Based on the presented data, a modified gene structure of the human VAT-1 homolog with an extended exon 1 is proposed. VAT-1 and the mammalian VAT-1 homolog form a subgroup within the protein superfamily of medium-chain dehydrogenases/reductases.
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Recently, interest has focused on the human gene encoding the putative protein homologous to VAT-1, the major protein of the synaptic vesicles of the electric organ of the Pacific electric ray Torpedo californica, after it has been localized on chromosome locus 17q21 in a region encompassing the breast cancer gene BRCA1. Chromosomal instability in this region is implicated in inherited predisposition for breast and ovarian cancer. Here we describe isolation and biochemical characterization of a mammalian 48 kDa protein homologous to the VAT-1 protein of Torpedo californica. This VAT-1 homolog was isolated from a murine breast cancer cell line (Ehrlich ascites tumor) and identified by sequencing of cleavage peptides. The isolated VAT-1 homolog protein displays an ATPase activity and exists in two isoforms with isoelectric points of 5.7 and 5.8. cDNA was prepared from Ehrlich ascites tumor cells, and the murine VAT-1 homolog sequence was amplified by polymerase chain reaction and partially sequenced. The known part of the murine and the human translated sequences share 97% identity. By Northern blots, the size of the VAT-1 homolog mRNA in both murine and human (T47D) breast cancer cells was determined to be 2.8 kb. Based on the presented data, a modified gene structure of the human VAT-1 homolog with an extended exon 1 is proposed. VAT-1 and the mammalian VAT-1 homolog form a subgroup within the protein superfamily of medium-chain dehydrogenases/reductases.
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skos:exactMatch | |
uniprot:name |
J. Cell. Biochem.
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uniprot:author |
Beckmann G.,
Benndorf R.,
Hayess K.,
Jandrig B.,
Janke J.,
Kraft R.,
Rohde K.,
Sachsinger J.
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uniprot:date |
1998
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uniprot:pages |
304-315
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uniprot:title |
Mammalian protein homologous to VAT-1 of Torpedo californica: isolation from Ehrlich ascites tumor cells, biochemical characterization, and organization of its gene.
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uniprot:volume |
69
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dc-term:identifier |
doi:10.1002/(SICI)1097-4644(19980601)69:3<304::AID-JCB8>3.3.CO;2-U
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