In:
American Journal of Physiology-Endocrinology and Metabolism, American Physiological Society, Vol. 284, No. 3 ( 2003-03-01), p. E514-E520
Abstract:
We evaluated whether insulin signaling modulates plasma cell glycoprotein (PC-1) plasma membrane recruitment, posttranslational processing, and gene expression in human cultured cell lines. Insulin induced a fourfold increase ( P 〈 0.01) of membrane PC-1 expression by rapid and sensitive mechanism(s). This effect was reduced ( P 〈 0.05–0.01) by inhibition of phosphatidylinositol 3-kinase (200 nmol/l wortmannin) and S6 kinase (50 nmol/l rapamycin) activities and intracellular trafficking (50 μmol/l monensin) and was not accompanied by PC-1 gene expression changes. Moreover, at Western blot, insulin elicited the appearance, in both plasma membrane and cytosol, of a PC-1-related 146-kDa band (in addition to bands of 163, 117, 106, and 97 kDa observed also in absence of insulin) that was sensitive to endoglycosidase H. Finally, inhibition of PC-1 translocation to plasma membrane, by wortmannin pretreatment, increases insulin-stimulated receptor autophosphorylation. Our data indicate that insulin stimulates PC-1 posttranslational processing and translocation to the plasma membrane, which in turn impairs insulin receptor signaling. Bidirectional cross talk between insulin and PC-1, therefore, takes place, which may be part of the hormone self-desensitization mechanism.
Type of Medium:
Online Resource
ISSN:
0193-1849
,
1522-1555
DOI:
10.1152/ajpendo.00503.2001
Language:
English
Publisher:
American Physiological Society
Publication Date:
2003
detail.hit.zdb_id:
1477331-4
SSG:
12
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