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Predicate | Object |
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rdf:type | |
lifeskim:mentions | |
pubmed:issue |
2
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pubmed:dateCreated |
1995-8-17
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pubmed:databankReference | |
pubmed:abstractText |
Avian gastrin is a gastric acid secretagogue, but is structurally more closely related to mammalian cholecystokinin, which is functionally distinct from gastrin. This apparently anomalous structure/activity relationship raises important issues for understanding the evolution of regulatory peptides and the mechanisms that control their expression. To clarify the possible mechanisms, we have determined the sequence of a 6.5-kb BamHI genomic DNA fragment that includes the entire avian gastrin transcriptional unit. The complete cDNA sequence, determined by anchored PCR, encoded a precursor of 105 amino acids. Conserved primary amino acid structures were limited to a decapeptide determining biological activity, and essential sites for post-translational processing. Significantly, however, the genomic regulatory regions, and introns, were unlike those of any previously reported gastrin/cholecystokinin gene. The avian gastrin gene contained no recognizable TATA-box motif, a feature unique to this gene family, but had a G+C-rich region immediately upstream of the transcription initiation site, and a Z-DNA purine-pyrimidine repeat sequence. Moreover, physiological regulation of the avian gastrin gene differed markedly from that observed in mammals, in that the important local paracrine downregulation by antral somatostatin was absent; instead, evidence for a hormonal regulation was demonstrated. The data indicate that genomic regulatory elements within regulatory peptide families such as the gastrin/cholecystokinin family, and mechanisms of physiological control, are not conserved during evolution, even though biologically important amino acid sequence information is retained.
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pubmed:grant | |
pubmed:language |
eng
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pubmed:journal | |
pubmed:citationSubset |
IM
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pubmed:chemical | |
pubmed:status |
MEDLINE
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pubmed:month |
Jun
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pubmed:issn |
0014-2956
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pubmed:author | |
pubmed:issnType |
Print
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pubmed:day |
1
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pubmed:volume |
230
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pubmed:owner |
NLM
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pubmed:authorsComplete |
Y
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pubmed:pagination |
439-46
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pubmed:dateRevised |
2007-11-14
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pubmed:meshHeading |
pubmed-meshheading:7607213-Amino Acid Sequence,
pubmed-meshheading:7607213-Animals,
pubmed-meshheading:7607213-Base Sequence,
pubmed-meshheading:7607213-Chickens,
pubmed-meshheading:7607213-DNA, Complementary,
pubmed-meshheading:7607213-Gastrins,
pubmed-meshheading:7607213-Gene Expression Regulation,
pubmed-meshheading:7607213-Molecular Sequence Data,
pubmed-meshheading:7607213-Sequence Homology, Amino Acid,
pubmed-meshheading:7607213-TATA Box
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pubmed:year |
1995
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pubmed:articleTitle |
Molecular characterization and physiological regulation of a TATA-less gene encoding chicken gastrin.
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pubmed:affiliation |
Department of Medicine, UCLA, USA.
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pubmed:publicationType |
Journal Article,
Research Support, U.S. Gov't, P.H.S.,
Research Support, Non-U.S. Gov't
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