Linked Life Data

9287308

Source:http://linkedlifedata.com/resource/pubmed/id/9287308

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
37
pubmed:dateCreated
1997-10-1
pubmed:abstractText
Rhodopsin, the photoreceptor molecule of the vertebrate rod cell, is a G protein-coupled receptor. Rhodopsin consists of the opsin apoprotein and its 11-cis-retinal chromophore, which is covalently bound to a specific lysine residue by a stable protonated Schiff base linkage. Rhodopsin activation occurs when light causes photoisomerization of the 11-cis chromophore to its all-trans form. The all-trans chromophore is the receptor agonist. The 11-cis-retinylidene chromophore is analogous pharmacologically to a potent inverse agonist of the receptor. We report here that replacement of a highly conserved glycine residue (Gly121) causes 11-cis-retinal to become a pharmacologic partial agonist. Although the mutant apoproteins do not display constitutive activity, they are active in the dark when bound to an 11-cis-retinylidene chromophore, or to a "locked" chromophore analogue, Ret-7. The degree of partial agonism is directly related to the size of the amino acid replacement at position 121, and it can be reversed by a specific second-site replacement of Phe261. Thus, mutation of Gly121 in rhodopsin causes 11-cis-retinal to act as a partial agonist rather than an inverse agonist, allowing the mutant pigment to activate transducin in the dark.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
12
pubmed:volume
272
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
23081-5
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1997
pubmed:articleTitle
Partial agonist activity of 11-cis-retinal in rhodopsin mutants.
pubmed:affiliation
Laboratory of Molecular Biology and Biochemistry, Rockefeller University, New York, New York 10021, USA.
pubmed:publicationType
Journal Article, Comparative Study, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't