Identification and characterization of novel human endogenous retroviral sequences prefentially expressed in undifferentiated embryonal carcinoma cells.
A novel endogenous retroviral sequence (ERV-9) has been isolated from a human embryonal carcinoma cDNA library by hybridization to a probe containing a recently described human repetitive element. DNA sequence analysis of the 4kb cDNA insert (pHE.1) revealed the presence of ORFs potentially coding for putative retrovirus-related gag, pol and env proteins. Northern blot and RNase protection experiments showed that RNA homologous to the pHE.1 insert is detected only in embryonal carcinoma cells as a 8 kb mRNA, and its expression is negatively regulated during retinoic acid induced differentiation of the human teratocarcinoma cell line NT2/D1. Using a pol specific probe we have isolated a genomic locus containing the ERV-9 sequences. Characterization by restriction enzyme analysis and DNA sequencing allowed us to define LTR-like sequences, that are composed by a complex array of subrepetitive elements. In addition we show that ERV-9 LTR sequences are capable to drive expression of linked CAT gene in a cell specific manner as LTR promoter activity has been detected only in NT2/D1 cells.
La Mantia
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G
Department of Genetics, General and Molecular Biology, University of Naples, Italy.
Maglione
D
D
Pengue
G
G
Di Cristofano
A
A
Simeone
A
A
Lanfrancone
L
L
Lania
L
L
D000595:Amino Acid Sequence; D001483:Base Sequence; D015139:Blotting, Southern; D004273:DNA, Neoplasm / Q000032:analysis / Q000235:genetics; D004279:DNA, Viral / Q000032:analysis / Q000235:genetics; D054278:Embryonal Carcinoma Stem Cells; D005814:Genes, Viral; D006801:Humans; D008969:Molecular Sequence Data; D014411:Neoplastic Stem Cells / Q000378:metabolism*; D016366:Open Reading Frames; D010957:Plasmids; D011401:Promoter Regions, Genetic; D012334:RNA, Neoplasm / Q000032:analysis / Q000235:genetics; D012367:RNA, Viral / Q000032:analysis / Q000235:genetics; D015183:Restriction Mapping; D012190:Retroviridae / Q000235:genetics*; D016415:Sequence Alignment; D014407:Tumor Cells, Cultured
D004273:DNA, Neoplasm; D004279:DNA, Viral; D012334:RNA, Neoplasm; D012367:RNA, Viral