Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
8
pubmed:dateCreated
2005-7-25
pubmed:abstractText
Sex steroid synthesis requires the 17,20 lyase activity of P450c17, which is enhanced by cytochrome b5, acting as an allosteric factor to promote association of P450c17 with its electron donor, P450 oxidoreductase. Cytochrome b5 is preferentially expressed in the fetal adrenal and postadrenarchal adrenal zona reticularis; the basis of this tissue-specific, developmentally regulated transcription of the b5 gene is unknown. We found b5 expression in all cell lines tested, including human adrenal NCI-H295A cells, where its mRNA is reduced by cAMP and phorbol ester. Multiple sites, between -83 and -122 bp upstream from the first ATG, initiate transcription. Deletional mutagenesis localized all detectable promoter activity within -327/+15, and deoxyribonuclease I footprinting identified protein binding at -72/-107 and -157/-197. DNA segments -65/-40, -114/-70 and -270/-245 fused to TK32/Luc yielded significant activity, and mutations in their Sp sites abolished that activity; electrophoretic mobility shift assay (EMSA) showed that Sp3, but not Sp1, binds to these Sp sites. Nuclear factor 1 (NF-1) and GATA-6, but not GATA-4 bind to the NF-1 and GATA sites in -157/-197. In Drosophila S2 cells, Sp3 increased -327/Luc activity 58-fold, but Sp1 and NF-1 isoforms were inactive. Mutating the three Sp sites ablated activity without or with cotransfection of Sp1/Sp3. In NCI-H295A cells, mutating the three Sp sites reduced activity to 39%; mutating the Sp, GATA, and NF-1 sites abolished activity. In JEG-3 cells, GATA-4 was inactive, GATA-6 augmented -327/Luc activity to 231% over the control, and steroidogenic factor 1 augmented activity to 655% over the control; these activities required the Sp and NF-1 sites. Transcription of cytochrome b5 shares many features with the regulation of P450c17, whose activity it enhances.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
http://linkedlifedata.com/resource/pubmed/chemical/Cytochromes b5, http://linkedlifedata.com/resource/pubmed/chemical/DNA, http://linkedlifedata.com/resource/pubmed/chemical/DNA, Complementary, http://linkedlifedata.com/resource/pubmed/chemical/Deoxyribonuclease I, http://linkedlifedata.com/resource/pubmed/chemical/GATA6 Transcription Factor, http://linkedlifedata.com/resource/pubmed/chemical/GATA6 protein, human, http://linkedlifedata.com/resource/pubmed/chemical/Homeodomain Proteins, http://linkedlifedata.com/resource/pubmed/chemical/Luciferases, http://linkedlifedata.com/resource/pubmed/chemical/NADPH-Ferrihemoprotein Reductase, http://linkedlifedata.com/resource/pubmed/chemical/NR5A1 protein, human, http://linkedlifedata.com/resource/pubmed/chemical/Oligonucleotides, http://linkedlifedata.com/resource/pubmed/chemical/Phorbol Esters, http://linkedlifedata.com/resource/pubmed/chemical/Protein Isoforms, http://linkedlifedata.com/resource/pubmed/chemical/RNA, Messenger, http://linkedlifedata.com/resource/pubmed/chemical/Receptors, Cytoplasmic and Nuclear, http://linkedlifedata.com/resource/pubmed/chemical/Ribonucleases, http://linkedlifedata.com/resource/pubmed/chemical/Steroidogenic Factor 1, http://linkedlifedata.com/resource/pubmed/chemical/Transcription Factors
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
0888-8809
pubmed:author
pubmed:issnType
Print
pubmed:volume
19
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
2020-34
pubmed:dateRevised
2009-8-12
pubmed:meshHeading
pubmed-meshheading:15831526-Adrenal Glands, pubmed-meshheading:15831526-Animals, pubmed-meshheading:15831526-Base Sequence, pubmed-meshheading:15831526-Binding Sites, pubmed-meshheading:15831526-Blotting, Northern, pubmed-meshheading:15831526-Cell Line, pubmed-meshheading:15831526-Cell Line, Tumor, pubmed-meshheading:15831526-Cytochromes b5, pubmed-meshheading:15831526-DNA, pubmed-meshheading:15831526-DNA, Complementary, pubmed-meshheading:15831526-Deoxyribonuclease I, pubmed-meshheading:15831526-Drosophila, pubmed-meshheading:15831526-GATA6 Transcription Factor, pubmed-meshheading:15831526-Gene Deletion, pubmed-meshheading:15831526-Genes, Reporter, pubmed-meshheading:15831526-HeLa Cells, pubmed-meshheading:15831526-Homeodomain Proteins, pubmed-meshheading:15831526-Humans, pubmed-meshheading:15831526-Luciferases, pubmed-meshheading:15831526-Molecular Sequence Data, pubmed-meshheading:15831526-Mutagenesis, pubmed-meshheading:15831526-Mutagenesis, Site-Directed, pubmed-meshheading:15831526-Mutation, pubmed-meshheading:15831526-NADPH-Ferrihemoprotein Reductase, pubmed-meshheading:15831526-Oligonucleotides, pubmed-meshheading:15831526-Phorbol Esters, pubmed-meshheading:15831526-Polymerase Chain Reaction, pubmed-meshheading:15831526-Promoter Regions, Genetic, pubmed-meshheading:15831526-Protein Binding, pubmed-meshheading:15831526-Protein Isoforms, pubmed-meshheading:15831526-RNA, Messenger, pubmed-meshheading:15831526-Receptors, Cytoplasmic and Nuclear, pubmed-meshheading:15831526-Reverse Transcriptase Polymerase Chain Reaction, pubmed-meshheading:15831526-Ribonucleases, pubmed-meshheading:15831526-Steroidogenic Factor 1, pubmed-meshheading:15831526-Transcription, Genetic, pubmed-meshheading:15831526-Transcription Factors, pubmed-meshheading:15831526-Transcriptional Activation, pubmed-meshheading:15831526-Transfection
pubmed:year
2005
pubmed:articleTitle
Regulation of cytochrome b5 gene transcription by Sp3, GATA-6, and steroidogenic factor 1 in human adrenal NCI-H295A cells.
pubmed:affiliation
Department of Pediatrics, University of California, San Francisco, San Francisco, California 94143-0978, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, N.I.H., Extramural