Linked Life Data

11073961

Source:http://linkedlifedata.com/resource/pubmed/id/11073961

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
5
pubmed:dateCreated
2001-5-23
pubmed:abstractText
The sst1 somatostatin (SRIF) receptor subtype is widely expressed in the endocrine, gastrointestinal, and neuronal systems as well as in hormone-sensitive tumors, yet little is known about its regulation. Here we investigated the desensitization, internalization, and phosphorylation of sst1 expressed in CHO-K1 cells. Treatment of cells with 100 nm SRIF for 30 min reduced maximal SRIF inhibition of adenylyl cyclase from 40 to 10%. This desensitization was rapid (t(12) < 2 min) and dependent on agonist concentration (EC(50) = 2 nm). However, internalization of receptor-bound ligand occurred slowly (t(12) > 180 min). Incubation of cells with SRIF also caused a rapid (t(12) < 2 min) increase in sst1 receptor phosphorylation in a dose-dependent manner (EC(50) = 1.3 nm), as determined in a mobility shift phosphorylation assay. Receptor phosphorylation was not affected by pertussis toxin, indicating a requirement for receptor occupancy rather than signaling. The protein kinase C activator, phorbol 12-myristate 13-acetate also stimulated sst1 receptor phosphorylation whereas forskolin did not. Both agonist- and phorbol 12-myristate 13-acetate-stimulated receptor phosphorylation occurred mainly on serine. These studies are the first to demonstrate phosphorylation of the sst1 receptor and suggest that phosphorylation mediated uncoupling, rather than sequestration, leads to its desensitization.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Feb
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
2
pubmed:volume
276
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
3709-17
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
2001
pubmed:articleTitle
Agonist-induced phosphorylation of somatostatin receptor subtype 1 (sst1). Relationship to desensitization and internalization.
pubmed:affiliation
Department of Integrative Biology and Pharmacology, University of Texas Health Science Center-Houston, Houston, Texas 77225, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't