Linked Life Data

1618850

Source:http://linkedlifedata.com/resource/pubmed/id/1618850

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
19
pubmed:dateCreated
1992-8-5
pubmed:abstractText
The long-term regulatory effect of insulin on glucose transport activity and glucose transporter expression was examined in Chinese hamster ovary (CHO) transfectants that overexpress either human insulin receptors of the wild type (CHO-R cells) or human insulin receptors mutated at two major autophosphorylation sites, Tyr1162 and Tyr1163 (CHO-Y2 cells). Previous studies showed that, when acutely stimulated by insulin, CHO-Y2 cells exhibit decreased receptor kinase activity along with decreased signaling of several pathways, including that for glucose transport, as compared with CHO-R cells. We now report the following. (i) When treated for 24 h with insulin (10(-10) to 10(-6) M), CHO-R and CHO-Y2 cells displayed closely similar concentration-dependent increases in 2-deoxyglucose uptake. In both transfectants, the maximal insulin-induced increase (approximately 3.5-fold) in uptake was cycloheximide-sensitive and was paralleled by equivalent increases in the levels of GLUT-1 immunoreactive protein and mRNA. (ii) By contrast, under similar conditions, CHO-Y2 cells exhibited a marked decrease in their response to insulin for [U-14C]glucose incorporation into glycogen (decreased sensitivity and maximal responsiveness) and for [U-14C]leucine incorporation into protein (decreased sensitivity) as compared with CHO-R cells. (iii) After a 24-h treatment with 10(-7) M insulin, CHO-R (but not CHO-Y2) cells showed a decreased ability to respond to a subsequent acute insulin stimulation of either receptor exogenous kinase activity or 2-deoxyglucose uptake as compared with respective untreated controls. These results indicate that (i) insulin receptors mutated at Tyr1162 and Tyr1163 retain normal signaling of the long-term stimulatory effect of insulin on glucose transport activity and GLUT-1 expression, but not on glycogenesis and overall protein synthesis; (ii) these three insulin signaling pathways may be triggered by distinct domains of the insulin receptor beta-subunit; and (iii) wild-type (but not twin-tyrosine mutant) receptors undergo negative regulation by chronic insulin treatment for subsequent signaling of acute biological actions of insulin.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jul
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
5
pubmed:volume
267
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
13488-97
pubmed:dateRevised
2011-11-17
pubmed:meshHeading
pubmed:year
1992
pubmed:articleTitle
Differential role of insulin receptor autophosphorylation sites 1162 and 1163 in the long-term insulin stimulation of glucose transport, glycogenesis, and protein synthesis.
pubmed:affiliation
Laboratoire de Biochimie, Institut National de la Santé et de la Recherche Médicale U 181, Faculté de Médecine Saint-Antoine, Paris, France.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't