Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
15
pubmed:dateCreated
2001-4-11
pubmed:abstractText
This study investigated the mechanism of agonist-induced opioid receptor down-regulation. Incubation of HEK 293 cells expressing FLAG-tagged delta and mu receptors with agonists caused a time-dependent decrease in opioid receptor levels assayed by immunoblotting. Pulse-chase experiments using [(35)S]methionine metabolic labeling indicated that the turnover rate of delta receptors was accelerated 5-fold following agonist stimulation. Inactivation of functional G(i) and G(o) proteins by pertussis toxin-attenuated down-regulation of the mu opioid receptor, while down-regulation of the delta opioid receptor was unaffected. Pretreatment of cells with inhibitors of lysosomal proteases, calpain, and caspases had little effect on mu and delta opioid receptor down-regulation. In marked contrast, pretreatment with proteasome inhibitors attenuated agonist-induced mu and delta receptor down-regulation. In addition, incubation of cells with proteasome inhibitors in the absence of agonists increased steady-state mu and delta opioid receptor levels. Immunoprecipitation of mu and delta opioid receptors followed by immunoblotting with ubiquitin antibodies suggested that preincubation with proteasome inhibitors promoted accumulation of polyubiquitinated receptors. These data provide evidence that the ubiquitin/proteasome pathway plays a role in agonist-induced down-regulation and basal turnover of opioid receptors.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
13
pubmed:volume
276
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
12345-55
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
2001
pubmed:articleTitle
Proteasome involvement in agonist-induced down-regulation of mu and delta opioid receptors.
pubmed:affiliation
Department of Biochemistry, University of Medicine and Dentistry of New Jersey, New Jersey Medical School, Newark, New Jersey 07103, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.