Linked Life Data

6547769

Source:http://linkedlifedata.com/resource/pubmed/id/6547769

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
5974
pubmed:dateCreated
1984-9-4
pubmed:databankReference
pubmed:abstractText
The structures of the genes coding for the opioid peptide precursors proopiomelanocortin, proenkephalin (proenkephalin A) and prodynorphin (proenkephalin B), are known for some mammalian species. To gain insight into the evolutionary history of these precursors, we have examined the proenkephalin gene in the South African clawed toad, Xenopus laevis, which diverged from the principal line of vertebrate evolution some 350 Myr ago. The human proenkephalin gene consists of four exons, of which the main exon (exon IV) contains all known biologically active peptides--six Met-enkephalin sequences and one Leu-enkephalin sequence. We report here the primary structures of the putative main exons of two proenkephalin genes in X. laevis, each of which codes for seven Met-enkephalin sequences but no Leu-enkephalin, indicating that Met-enkephalin preceded Leu-enkephalin in the evolution of the proenkephalin gene. The organization of the main exons of the toad genes is remarkably similar to that of the human gene and conserved regions provide evidence for functionally significant structures. We also detect a polymorphism in one of the toad proenkephalin genes, mapping 1.5 kilobases (kb) 5' of the main exon; it is caused by an insertion/deletion of a 1-kb repetitive sequence which has the characteristics of a transposable element.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:issn
0028-0836
pubmed:author
pubmed:issnType
Print
pubmed:volume
310
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
251-4
pubmed:dateRevised
2010-11-18
pubmed:meshHeading
pubmed:articleTitle
Polymorphism and absence of Leu-enkephalin sequences in proenkephalin genes in Xenopus laevis.
pubmed:publicationType
Journal Article, Comparative Study, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't