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)

Recent studies indicate that a purified protein, activin A, belongs to the transforming growth factor beta (TGF-beta) superfamily. Similar to TGF-beta, activin A can have different biologic activities, depending on the target tissues. We used recombinant activin A to demonstrate a possible regulatory role of this protein in modulating human erythroid differentiation in the human erythroid cell line, K562. Using genomic probes containing the second exon of alpha, beta, gamma, and epsilon globins, relative abundance of various types of globin transcripts in untreated and activin-treated K562 cells was examined with S1 nuclease analysis. Despite considerable homology amongst various globin sequences, these globin probes were highly specific for their unique mRNA species in the analyses. It was shown that the abundance of specific globin probe fragments for gamma and epsilon globins (209 nucleotides) as well as alpha (180 nucleotides), which were protected from S1 digestion, increased many fold in K562 cells treated with activin A. In contrast, there were no specific transcripts of beta globin detected in either the control or activin-treated cells. The increases in the level of fetal and embryonic beta-like and alpha globin transcripts also confirmed earlier studies of Northern and slot-blot analyses using globin cDNA as probes. In addition, nuclear run-off transcription assay using isolated nuclei indicated that most of the increase in the globin transcripts after activin treatment could be attributed to the stimulation of transcription rate for globin genes. Transient transfection assays also provide evidence that activin A significantly stimulated transcriptional activity of an epsilon globin promoter in K562, but not in the nonerythroid Chinese hamster ovary cells. Therefore, it was concluded that activin A exerts its effects on globin gene expression at the level of transcription in erythroid cells.
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PMID:Regulation of globin gene expression in human K562 cells by recombinant activin A. 173 15

Double-stranded DNA synthesized from the pigeon globin mRNA by the subsequent actions of avian myeloblastosis virus reverse transcriptase and E. coli DNA polymerase I was split with nuclease S1 and inserted into PstI site in the plasmid pBR322 by poly(dG) times poly(dC) homopolymer extension technique using terminal deoxynucleotidyl transferase. E. coli transformants have been shown to contain pigeon globin sequences by colony hybridization with pigeon globin [32P]cDNA. The inserted DNA fragment deleted from recombinant DNA by PstI treatment hybridizes with globin cDNA. The maximal length of the inserted fragment measured in agarose gel was found to be 550--560 base pairs. Inserted sequences subjected to analysis by hybridization with alpha- and beta-[32P]cDNA have been ascribed to the pigeon alpha globin chain. EcoRI, HindIII, BglII, SalI, BamHI, PstI restriction enzymes did not cleave the inserted DNA fragment. Pigeon DNA coding alpha-globin chain contains recognition sites for AluI, HindII and HaeIII restriction enzymes. Part of the recombinant clones remains resistant to ampicillin and therefore in some of these clones the globin gene could be expressed.
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PMID:[Enzymatic synthesis and molecular cloning of the pigeon alpha-globin structural gene]. 617 3

Nucleotide sequence analysis of a recombinant cDNA for a duck alpha-globin gene indicates a gene with novel features and evolutionary history. The duck alpha-globin double-stranded cDNA, treated with S1 nuclease and tailed with poly(dC), was inserted into the PstI restriction endonuclease site of pBR322 tailed with poly(dG). Nucleotide sequence analysis of the resulting recombinant cDNA indicates that it contains the translated region and all of the 3' untranslated region for an alpha-globin gene. The sequence was determined by procedures designed especially for rapid analysis of pBR322 (PstI site) recombinant cDNAs. This duck globin has sequences related to the chicken alpha-A globin in some regions but in other regions it is more closely related to another alpha globin found in anemic chickens.
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PMID:Nucleotide sequence for a novel duck alpha-globin gene. 689 64