Linked Life Data

14565597

Source:http://linkedlifedata.com/resource/pubmed/id/14565597

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
2003-10-20
pubmed:abstractText
Desensitization of G-protein coupled receptors (GPCR's) is largely mediated by a family of enzymes and protein co-factors termed GRKs and arrestins, respectively. In the present studies, we investigated expression of GRKs and arrestins in osteoblastic cell lines concentrating on the enzymes (GRK2 and GRK3) and protein co-factors (beta-arrestint 1 and beta-arrestin 2) that play dominant roles in regulating GPCR responsiveness in most tissues and cell types. We found that osteoblastic cells express similar amounts of GRK2 with either undetectable or lesser amounts of GRK3. In contrast, expression of beta-arrestin 1 and beta-arrestin 2 by osteoblastic cells varied between cell lines. To determine if GRK2 or beta-arrestin expression is modulated during osteoblast development, we assessed expression of GRK2 and beta-arrestin proteins during differentiation of the mouse osteoblastic cell line MC3T3-E1 cells over a 21-day period. We found that expression of GRK2 and beta-arrestin 2 increased to maximal levels by day 7 and then decreased 4-fold by day 21. In contrast, expression of beta-arrestin 1 increased to maximal levels by day 14 and then decreased 2-fold by day 21. Over this same time period (days 7-21), PTH/PTHrP receptor number decreased to a greater extent than the decrease in PTH(1-34)-induced cAMP generation, suggesting that responsiveness of individual PTH/PTHrP receptors was enhanced in differentiated cells. We conclude that (1) osteoblastic cell lines differentially express the enzymes and protein co-factors that modulate GPCR responsiveness and (2) expression of both GRK2 and beta-arrestins is temporally regulated during osteoblast development. These data are consistent with the notion that GPCR responsiveness may be differentially regulated in osteoblastic cell lines and during osteoblast development.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
0171-967X
pubmed:author
pubmed:issnType
Print
pubmed:volume
73
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
153-60
pubmed:dateRevised
2007-11-15
pubmed:meshHeading
pubmed:year
2003
pubmed:articleTitle
Regulated expression of G protein-coupled receptor kinases (GRK's) and beta-arrestins in osteoblasts.
pubmed:affiliation
Division of Nephrology, Department of Medicine, Duke University and Durham VA Medical Centers, Durham, NC 27710, USA. spurn002@mc.duke.edu
pubmed:publicationType
Journal Article, Comparative Study, Research Support, U.S. Gov't, P.H.S.