Linked Life Data

10896945

Source:http://linkedlifedata.com/resource/pubmed/id/10896945

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
39
pubmed:dateCreated
2000-10-27
pubmed:abstractText
Phosducin and phosducin-like protein regulate G protein signaling pathways by binding the betagamma subunit complex (Gbetagamma) and blocking Gbetagamma association with Galpha subunits, effector enzymes, or membranes. Both proteins are composed of two structurally independent domains, each constituting approximately half of the molecule. We investigated the functional roles of the two domains of phosducin and phosducin-like protein in binding retinal G(t)betagamma. Kinetic measurements using surface plasmon resonance showed that: 1) phosducin bound G(t)betagamma with a 2. 5-fold greater affinity than phosducin-like protein; 2) phosphorylation of phosducin decreased its affinity by 3-fold, principally as a result of a decrease in k(1); and 3) most of the free energy of binding comes from the N-terminal domain with a lesser contribution from the C-terminal domain. In assays measuring the association of G(t)betagamma with G(t)alpha and light-activated rhodopsin, both N-terminal domains inhibited binding while neither of the C-terminal domains had any effect. In assays measuring membrane binding of G(t)betagamma, both the N- and C-terminal domains inhibited membrane association, but much less effectively than the full-length proteins. This inhibition could only be described by models that included a change in G(t)betagamma to a conformation that did not bind the membrane. These models yielded a free energy change of +1.5 +/- 0.25 kcal/mol for the transition from the G(t)alpha-binding to the Pd-binding conformation of G(t)betagamma.
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
29
pubmed:volume
275
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
30399-407
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed-meshheading:10896945-Animals, pubmed-meshheading:10896945-Binding Sites, pubmed-meshheading:10896945-Carrier Proteins, pubmed-meshheading:10896945-Cattle, pubmed-meshheading:10896945-Eye Proteins, pubmed-meshheading:10896945-GTP-Binding Protein Regulators, pubmed-meshheading:10896945-Kinetics, pubmed-meshheading:10896945-Models, Chemical, pubmed-meshheading:10896945-Models, Molecular, pubmed-meshheading:10896945-Nerve Tissue Proteins, pubmed-meshheading:10896945-Phosphoproteins, pubmed-meshheading:10896945-Protein Binding, pubmed-meshheading:10896945-Protein Structure, Tertiary, pubmed-meshheading:10896945-Rats, pubmed-meshheading:10896945-Rhodopsin, pubmed-meshheading:10896945-Rod Cell Outer Segment, pubmed-meshheading:10896945-Surface Plasmon Resonance, pubmed-meshheading:10896945-Transducin
pubmed:year
2000
pubmed:articleTitle
Functional roles of the two domains of phosducin and phosducin-like protein.
pubmed:affiliation
Department of Chemistry and Biochemistry, Brigham Young University, Provo, Utah 84602, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.