Linked Life Data

10204689

Source:http://linkedlifedata.com/resource/pubmed/id/10204689

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1999-6-3
pubmed:abstractText
Agonist-activated beta2-adrenoceptors rapidly internalize and then recycle to the cell surface, however chronic agonist eventually causes receptor downregulation. To characterize beta2-adrenoceptor trafficking kinetics and intracellular sorting during downregulation, human embryonic kidney cells expressing epitope-tagged receptors were examined by radioligand binding with (+/-)-[3H]4-(3-tertiarybutylamino-2-hydroxypropoxy)-benzimidazole- 2-on hydrochloride ([3H]CGP12177) and immunofluorescence microscopy. The first-order receptor recycling rate constant declined after 18 h of agonist compared with 15 min (0.05 min(-1) vs. 0.12 min(-1)), thus increasing the intracellular transit time (20.0 min vs. 8.3 min). There was also a reduction in the rate of receptor endocytosis and a decline in the total number of receptors. Although the intracellular receptor fraction did not increase between 15 min and 18 h of agonist, some receptors moved irreversibly into a protease-containing compartment while retaining radioligand binding activity. Our results indicate that beta2-adrenoceptor downregulation is associated principally with an increased intracellular transit time during recycling. This could promote the diversion of receptors into protease-containing compartments, where there is an irreversible commitment to downregulation prior to loss of radioligand binding activity.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
0014-2999
pubmed:author
pubmed:issnType
Print
pubmed:day
12
pubmed:volume
369
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
113-23
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1999
pubmed:articleTitle
Specific changes in beta2-adrenoceptor trafficking kinetics and intracellular sorting during downregulation.
pubmed:affiliation
Department of Pediatrics (Pulmonary), Baylor College of Medicine, Houston, TX 77030, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't