Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.1.30.2 (endonuclease)
 18,621 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Human endogenous retroviral element S71 had previously been shown to contain gag- and pol-related regions and a 3' LTR-like sequence. The nucleotide sequence of S71 was determined and compared with the corresponding regions of SSV and its helper virus SSAV. The 1.48-kb S71 gag region consists of matrix protein p15 (MA)-, capsid protein p30 (CA)-, and nucleocapsid protein p10 (NC)-related sections and the 1.82-kb pol region of tether, RNase H (RH), and endonuclease/integrase (IN) sections. The S71 nucleotide sequence contains a 167 amino acid open reading frame encompassing MA. The boundaries of the S71 element are delimited by direct repeats and the entire element is 5.4 kb long. Similarity between S71 and the v-sis-bearing, defective SSV provirus also covers overall structural organization, including the presence of presumably nonretroviral sequences. Both the gag and the pol regions of S71 contain sequences highly conserved in numerous retroviruses. Phylogenetic analysis with conserved CA, RH, and IN sequences showed that of all other (C-type) human retroviral elements available for comparison, S71 is most closely related to infectious primate and murine retroviruses. This suggests that S71 represents a phylogenetic subgroup of its own. In addition we identified short ranges of conserved amino acid sequences within C-type retroviral gag and pol genes sufficient for phylogenetic analysis. Use of these may facilitate large-scale phylogenetic evaluation of C-type retroviral elements and allow rapid classification of new elements.
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PMID:S71 is a phylogenetically distinct human endogenous retroviral element with structural and sequence homology to simian sarcoma virus (SSV). 215 93

Enhanced expression of the human SIS/PDGF-2 gene has been reported in a number of human cell lines, sarcomas, and glioblastomas. We have analyzed the SIS/PDGF-2 gene for structural alterations in fresh human tumors. DNA samples from 79 patients with solid tumors (63 mesenchymal tumors, 12 lung carcinomas, 4 breast carcinomas) were examined and compared with DNA samples from 50 leukemia patients and 14 unrelated individuals without malignant neoplasms. When DNA samples were digested with a HindIII restriction endonuclease, Southern blot analysis demonstrated two distinct bands (21kb and 18kb) after hybridization to the SIS/PDGF-2 gene probe. A pedigree analysis of a 43-member family indicated that these allelic variants segregated in a Mendelian fashion. There was, however, tumor specific allele loss in 18% of the mesenchymal tumors analyzed, which may indicate a common etiology for this tumor type.
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PMID:Reduction to homozygosity at the SIS/PDGF-2 locus in human mesenchymal tumors. 290 34

Feline and human genetic sequences, homologous to the v-sis gene of simian sarcoma virus, have been isolated from cosmid gene libraries and characterized by restriction endonuclease analysis. Comparison of the two loci revealed their related structural organization. In both loci, similar unique genetic sequences were found upstream of the v-sis homologous region and these hybridized to a 4.2 kbp c-sis transcript in human lung tumor cells. These data establish and map as yet unidentified coding sequences at the 5' part of the c-sis proto-oncogene of both species.
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PMID:Comparative analysis of the human and feline c-sis proto-oncogenes. Identification of 5' human c-sis coding sequences that are not homologous to the transforming gene of simian sarcoma virus. 298 25

The expression of c-abl, c-sis, c-myc and N-ras oncogenes was examined in 2 lymphoblastoid cell lines, one with Ph1 (PB-1049) and the other without Ph1 (LN-1049), both established from a patient with chronic myelogenous leukemia (CML), and in a Ph1-positive cell line (PB-1049-T) derived from a tumor formed after transplantation of PB-1049 cells in a nude mouse with reference to their tumorigenic potential in nude mice. The normal transcripts of c-abl were detected in all 3 lymphoblastoid cell lines. Although in situ hybridization of v-abl proved, and restriction endonuclease analyses of the bcr region strongly indicated the occurrence of bcr-abl rearrangement in PB-1049 and PB-1049-T, we could not obtain any evidence for the expression of the hybrid bcr-abl mRNA. These results indicate that the Ph1 translocation does not ensure the production of the hybrid bcr-abl mRNA, and that the expression of hybrid bcr-abl gene is not essential for the maintenance of tumorigenicity of these cell lines. Expression of c-sis was not detected in any of the cell lines examined, whereas the expression of c-myc was uniformly higher in the 3 cell lines than in normal control cells. The levels of N-ras expression varied considerably, probably in parallel with the changes in tumorigenicity of the cell lines. N-ras expression in the PB-1049 and PB-1049-T cell lines was higher than that in the LN-1049 line when they retained tumorigenic potential, but it fell to the level of LN-1049 with loss or decline of tumorigenicity.
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PMID:Absence of the hybrid bcr-abl mRNA in Ph1-positive B lymphoblastoid cell lines established from a patient with chronic myelogenous leukemia. 312 21