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)

We have determined the structure of the human ferrochelatase gene after isolation and characterization of lambda phage clones mapping discrete regions of the cDNA. This gene was assigned to human chromosome 18 at region q21.3, by fluorescent in situ hybridization. The gene contains a total of 11 exons and has a minimum size of about 45 kb. The exon/intron boundary sequences conform to consensus acceptor (GTn) and donor (nAG) sequences, and the exons in the gene appear to encode functional protein domains. A major site of the transcription initiation, determined by S1 nuclease mapping, was assigned to an adenine base 89 bases upstream from the adenine base of the translation initiation ATG. The promoter region contains a potential binding site for Sp1, NF-E2 and erythroid-specific transcriptional factor GATA-1, but not a typical TATAA or CCAAT sequence. Analysis of primer extension showed that the transcription starts at the same position between hepatoma HepG2 and erythroleukemia K562 cell mRNA, thereby suggesting that there can be a single transcript in erythroid and non-erythroid cells.
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PMID:Structure of the human ferrochelatase gene. Exon/intron gene organization and location of the gene to chromosome 18. 155 82

Glycophorins A (GPA) and B (GPB) are specifically expressed in human erythrocytes and express MN and Ss blood group antigens. While the GPB gene produces one transcript, the GPA gene produces three or four transcripts of different sizes. To understand the mechanisms of production of the different transcripts and erythroid-specific expression, we characterized the transcripts and the transcriptional regulatory regions of the glycophorin A gene. The transcriptional start site was determined by primer extension and S1 nuclease protection analysis, and it was found that all of the transcripts start at one major site. The nucleotide sequence of the newly isolated longest GPA cDNA revealed several polyadenylation signal sequences. To determine which polyadenylation signals are utilized, cDNA clones encoding GPA were isolated from a cDNA library of human erythroleukemia cell line K562 and the 3'-regions of the cDNAs were specifically amplified by the polymerase chain reaction. These results showed that five different polyadenylation signals of the GPA gene are utilized and the size and abundance of the transcripts are consistent with those detected by Northern blot analysis of K562 mRNAs. The 5'-flanking sequence was found to contain several binding motifs for the transcription factors, which were also found in other erythroid-specific genes. These motifs include the binding sites for the GATA-1 and NF-E2 erythroid-specific transcription factors, in addition to Sp1 transcription factor. The 5'-sequence from -750 to +36 relative to the transcriptional start site could confer only a low basal transcriptional activity in K562 cells and Friend erythroleukemia cells. This activity was significantly increased after Friend erythroleukemia cells were differentiated by dimethylsulfoxide. These results suggest that the 5' region regulates the glycophorin gene expression in erythroid-specific fashion.
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PMID:Characterization of glycophorin A transcripts: control by the common erythroid-specific promoter and alternative usage of different polyadenylation signals. 779 77