Linked Life Data

9020189

Source:http://linkedlifedata.com/resource/pubmed/id/9020189

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
7
pubmed:dateCreated
1997-3-14
pubmed:abstractText
Phosducin, which tightly binds betagamma-subunits of heterotrimeric G-proteins, has been conjectured to play a role in regulating second messenger signaling cascades, but to date its specific function has not been elucidated. Here we demonstrate a potential role for phosducin in regulating olfactory signal transduction. In isolated olfactory cilia certain odorants elicit a rapid and transient cAMP response, terminated by a concerted process which requires the action of two protein kinases, protein kinase A (PKA) and a receptor-specific kinase (GRK3) (Schleicher, S., Boekhoff, I. Arriza, J., Lefkowitz, R. J., and Breer, H. (1993) Proc. Natl. Acad. Sci. U. S. A. 90, 1420-1424). The mechanism of action of GRK3 involves a Gbetagamma-mediated translocation of the kinase to the plasma membrane bound receptors (Pitcher, J. A., Inglese, J., Higgins, J. B. , Arriza, J. L., Casey, P. J., Kim, C., Benovic, J. L., Kwatra, M. M. , Caron, M. G., and Lefkowitz, R. J. (1992) Science 257, 1264-1267). A protein with a molecular mass of 33 kDa that comigrates on SDS gels with recombinant phosducin and which is immunoreactive with phosducin antibodies is present in olfactory cilia. Recombinant phosducin added to permeabilized olfactory cilia preparations strongly inhibits termination of odorant-induced cAMP response and odorant-induced membrane translocation of GRK3. In addition, the cAMP analogue dibutyryl cAMP stimulates membrane targeting of the receptor kinase. This effect is presumably due to PKA-mediated phosphorylation of phosducin, which diminishes its affinity for binding to the Gbetagamma-subunit, thereby making Gbetagamma available to function as a membrane anchor for GRK3. A specific PKA inhibitor blocks the odorant-induced translocation of the receptor kinase. Consistent with this formulation, a non-phosphorylatable mutant of phosducin (phosducin Ser-73 --> Ala) is an even more effective inhibitor of desensitization and membrane targeting of GRK3 than the wild-type protein. A phosducin mutant that mimics phosphorylated phosducin (phosducin Ser-73 --> Asp) lacks this property and in fact recruits GRK3 to the membrane and potentiates desensitization. These results suggest that phosducin may act as a phosphorylation-dependent switch in second messenger signaling cascades, regulating the kinetics of desensitization processes by controlling the activity of Gbetagamma-dependent GRKs.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
http://linkedlifedata.com/resource/pubmed/chemical/ADRBK2 protein, human, http://linkedlifedata.com/resource/pubmed/chemical/Adrbk2 protein, rat, http://linkedlifedata.com/resource/pubmed/chemical/Cyclic AMP, http://linkedlifedata.com/resource/pubmed/chemical/Eye Proteins, http://linkedlifedata.com/resource/pubmed/chemical/G-Protein-Coupled Receptor Kinase 3, http://linkedlifedata.com/resource/pubmed/chemical/GTP-Binding Protein Regulators, http://linkedlifedata.com/resource/pubmed/chemical/Membrane Proteins, http://linkedlifedata.com/resource/pubmed/chemical/Phosphoproteins, http://linkedlifedata.com/resource/pubmed/chemical/Protein-Serine-Threonine Kinases, http://linkedlifedata.com/resource/pubmed/chemical/Receptor Protein-Tyrosine Kinases, http://linkedlifedata.com/resource/pubmed/chemical/phosducin
pubmed:status
MEDLINE
pubmed:month
Feb
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
14
pubmed:volume
272
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
4606-12
pubmed:dateRevised
2009-11-19
pubmed:meshHeading
pubmed:year
1997
pubmed:articleTitle
Phosducin, potential role in modulation of olfactory signaling.
pubmed:affiliation
University Stuttgart-Hohenheim, Institute of Zoophysiology, 70599 Stuttgart, Federal Republic of Germany.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't