Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.1.30.1 (S1 nuclease)
 3,660 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Using a monoclonal antibody to the interleukin 3 (IL-3) receptor (anti-Aic2), we isolated a cDNA (AIC2B) from a mouse mast cell line which is homologous to the previously characterized gene for the IL-3 receptor (AIC2A). This cDNA encodes a polypeptide of 896 amino acid residues and has 91% amino acid sequence identity with the IL-3 receptor. A consensus sequence defining an additional cytokine receptor family is present in this clone. Compared to the AIC2A clone, the AIC2B cDNA encodes a protein with amino acid substitutions, insertions, and deletions dispersed throughout the entire protein. Oligonucleotide probes specific for each cDNA hybridized with different genomic fragments, indicating that the AIC2A and AIC2B proteins are encoded by two distinct genes. Fibroblasts transfected with the AIC2B cDNA expressed the protein at the cell surface as determined by binding with the anti-Aic2 antibody but did not bind IL-3 or other cytokines, including IL-2, IL-4, granulocyte-macrophage colony-stimulating factor, erythropoietin, and IL-9 (p40) at concentrations between 1 and 10 nM. An S1 nuclease protection assay was used to discriminate between the AIC2A and AIC2B transcripts. We found that the AIC2B gene was coexpressed with the AIC2A gene. These results suggest a potential involvement of AIC2B in cytokine signal transduction.
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PMID:Cloning and expression of a gene encoding an interleukin 3 receptor-like protein: identification of another member of the cytokine receptor gene family. 169 79

Splenic erythroblasts of mice infected with the anemia-inducing strain of Friend virus can be isolated in large numbers with less than 5% contamination with other cell types. In short-term culture, the isolated cells will initiate globin synthesis and undergo other aspects of terminal differentiation only if erythropoietin (EP) is added to the medium. An early effect of the hormone on these cells is stimulation of total RNA synthesis. EP also causes initiation of transcription of the beta-globin genes after a lag period of 4 to 6 h. By 6 h, the transcription rate of beta-globin RNA is enhanced threefold, and by 12 h, it is nearly maximal at ca. 20 times the level of control cells which received no EP. Transcription rates of alpha and beta-globin genes are approximately equal to each other throughout the period of terminal differentiation. In the splenic erythroblasts, the chromatin structure in the vicinity of the beta-major globin gene was analyzed with two nucleases during these transcription rate changes. No S1 nuclease-hypersensitive site is detectable near the gene. The beta-major gene is quite sensitive to DNase I in comparison with the albumin gene; however, the level of sensitivity is the same before EP addition as it is during maximal gene transcription after EP addition. Also, a hypersensitive site near the 5' cap site of the beta-major gene is quantitatively equivalent both before and after EP addition. Analysis of cytosine methylation at two sites upstream from the gene showed no changes upon induction of beta-globin gene transcription by EP. Thus, the initiation of beta-globin transcription by EP appears to be at some step after chromatin structural alteration such as synthesis, release, or activation of a specific transcription initiation factor.
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PMID:Control of globin gene transcription by erythropoietin in erythroblasts from friend virus-infected mice. 399 Jun 88

We previously identified a translocation breakpoint in exon 8 of the erythropoietin receptor (EpoR) gene in TF-1 cells, a cell line derived from a human erythroleukemia. To investigate the potential pathogenetic significance of this abnormality, we more precisely mapped the breakpoint within exon 8 and studied the expression of the translocated gene by S1 nuclease mapping of EpoR transcripts and chemical crosslinking of labeled erythropoietin (Epo) to TF-1 cell surface receptors. Transcripts from the abnormal gene were found to be highly expressed in relation to normal EpoR transcripts in TF-1 cells. The breakpoint predicted by S1 mapping of abnormal EpoR transcripts agreed closely with that determined by Southern analysis. Chemical cross-linking of 125I-Epo to TF-1 cells showed an abnormal, low-molecular-weight cross-linked species directly recognized by anti-EpoR antibodies and present in considerable excess over the normal EpoR. Karyotype analysis showed that each of 10 TF-1 cell metaphases had, in addition to multiple other alterations, one chromosome 19 with additional chromosomal material translocated onto the short arm at 19p13.3, the location of the EpoR gene. We conclude that the structurally abnormal EpoR gene in TF-1 cells is highly expressed and produces an abnormal protein. We speculate that the chromosomal material brought into the EpoR locus by translocation is responsible for the high level of expression. We hypothesize that this translocation participated in the evolution of the erythroleukemia from which TF-1 cells were derived.
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PMID:A translocated erythropoietin receptor gene in a human erythroleukemia cell line (TF-1) expresses an abnormal transcript and a truncated protein. 780 93