Linked Life Data

19556343

Source:http://linkedlifedata.com/resource/pubmed/id/19556343

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
9
pubmed:dateCreated
2009-8-28
pubmed:abstractText
Activation of Wnt signaling pathways causes release and stabilization of the transcription regulator beta-catenin from a destruction complex composed of axin and the adenomatous polyposis coli (APC) protein (canonical signaling pathway). Assembly of this complex is facilitated by a protein-protein interaction between APC and a regulator of G protein signaling (RGS) domain in axin. Because G protein-coupled receptor kinase 2 (GRK2) has a RGS domain that is closely related to the RGS domain in axin, we determined whether GRK2 regulated canonical signaling. We found that GRK2 inhibited Wnt1-induced activation of a reporter construct as well as reduced Wnt3a-dependent stabilization and nuclear translocation of beta-catenin. GRK2 enzymatic activity was required for this negative regulatory effect, and depletion of endogenous GRK2 using small interfering RNA enhanced canonical signaling. GRK2-dependent inhibition of canonical signaling is relevant to osteoblast (OB) biology because overexpression of GRK2 attenuated Wnt/beta-catenin signaling in calvarial OBs. Coimmunoprecipitation studies found that: 1) GRK2 bound APC; 2) The GRK2-APC interaction was promoted by GRK2 enzymatic activity; and 3) Deletion of the RGS domain in GRK2 prevented both the GRK2-APC interaction and GRK2-dependent inhibition of canonical signaling. These data suggest that: 1) GRK2 negatively regulates Wnt signaling; 2) GRK2-dependent inhibition of canonical signaling requires a protein-protein interaction between the RGS domain in GRK2 and APC; and 3) Enzymatic activity promotes the GRK2-APC interaction and is required for the negative regulatory effect on canonical signaling. We speculate that inhibiting GRK2 activity in bone-forming OBs might be a useful therapeutic strategy for increasing bone mass.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
1944-9917
pubmed:author
pubmed:issnType
Electronic
pubmed:volume
23
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1455-65
pubmed:dateRevised
2010-9-2
pubmed:meshHeading
pubmed:year
2009
pubmed:articleTitle
Inhibition of WNT signaling by G protein-coupled receptor (GPCR) kinase 2 (GRK2).
pubmed:affiliation
Department of Medicine, Duke University Medical Center, Durham, North Carolina 27710, USA.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't, Research Support, N.I.H., Extramural