Linked Life Data

18339716

Source:http://linkedlifedata.com/resource/pubmed/id/18339716

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
6
pubmed:dateCreated
2008-5-21
pubmed:abstractText
Tight control of insulin action in liver is a crucial determinant for the regulation of energy homeostasis. Growth factor receptor-bound protein 14 (Grb14) is a molecular adapter, highly expressed in liver, which binds to the activated insulin receptor and inhibits its tyrosine kinase activity. The physiological role of Grb14 in liver metabolism was unexplored. In this study we used RNA interference to investigate the consequences of Grb14 decrease on insulin-regulated intracellular signaling, and on glucose and lipid metabolism in mouse primary cultured hepatocytes. In Grb14-depleted hepatocytes, insulin-induced phosphorylation of Akt, and of its substrates glycogen synthase kinase 3 and fork-head box protein 1, was increased. These effects on insulin signaling are in agreement with the selective inhibitory effect of Grb14 on the receptor kinase. However, the metabolic and genic effects of insulin were differentially regulated after Grb14 down-regulation. Indeed, the insulin-mediated inhibition of hepatic glucose production and gluconeogenic gene expression was slightly increased. Surprisingly, despite the improved Akt pathway, the induction by insulin of sterol regulatory element binding protein-1c maturation was totally blunted. As a result, in the absence of Grb14, glycogen synthesis as well as glycolytic and lipogenic gene expression were not responsive to the stimulatory effect of insulin. This study provides evidence that Grb14 exerts a dual role on the regulation by insulin of hepatic metabolism. It inhibits insulin receptor catalytic activity, and acts also at a more distal step, i.e. sterol regulatory element binding protein-1c maturation, which effect is predominant under short-term inhibition of Grb14 expression.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
AIM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
0013-7227
pubmed:author
pubmed:issnType
Print
pubmed:volume
149
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
3109-17
pubmed:dateRevised
2011-11-17
pubmed:meshHeading
pubmed:year
2008
pubmed:articleTitle
Dual effect of the adapter growth factor receptor-bound protein 14 (grb14) on insulin action in primary hepatocytes.
pubmed:affiliation
Institut Cochin, Université Paris Descartes, Centre National de la Recherche Scientifique (Unité Mixte de Recherche 8104), 75014 Paris, France.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't