Linked Life Data

9230059

Source:http://linkedlifedata.com/resource/pubmed/id/9230059

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
30
pubmed:dateCreated
1997-8-8
pubmed:abstractText
Arrestin quenches signal transduction in rod photoreceptors by blocking the catalytic activity of photoactivated phosphorylated rhodopsin toward the G protein, transducin (Gt). Rod cells also express a splice variant of arrestin, termed p44, in which the last 35 amino acids are replaced by a single Ala. In contrast to arrestin, this protein has been reported to bind to both the phosphorylated and nonphosphorylated forms of the activated receptor. In this study, we analyzed formation of the rhodopsin-p44 complex in vitro. Like arrestin, p44 stabilized the meta II (MII) photoproduct relative to forms MI and MIII and did not interact measurably with the apoprotein opsin. However, several differences between p44 and its parent protein were found: (i) p44 binds to nonphosphorylated MII with a much lower affinity (KD = 0.24 microM) than to phosphorylated MII (P-MII) (KD = 12 nM); arrestin binds only to P-MII (KD = 20 nM); (ii) p44 interacted also with truncated MII (329G-Rho MII), which lacked the sites of phosphorylation; (iii) with both MII and P-MII, the activation energy of complex formation with p44 was lower than that found for arrestin (70 kJ/mol instead of 140 kJ/mol); and (iv) InsP6 inhibited poorly the interaction between p44 and P-MII, but it strongly inhibited the interaction between arrestin and P-MII. Extrapolation of the measured on-rates to physiological conditions yielded reaction times for the binding of p44 to activated rhodopsin. The data suggest that the splice variant, p44, and its parent protein, arrestin, play different roles in phototransduction. The physiological significance of these differences remains to be determined.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jul
pubmed:issn
0006-2960
pubmed:author
pubmed:issnType
Print
pubmed:day
29
pubmed:volume
36
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
9253-60
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed:year
1997
pubmed:articleTitle
Functional differences in the interaction of arrestin and its splice variant, p44, with rhodopsin.
pubmed:affiliation
Institut für Medizinische Physik und Biophysik, Charité, Medizinische Fakultät der Humboldt-Universität zu Berlin, Ziegelstrasse 5-9, 10098 Berlin, Germany.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't