Protein kinase B is expressed in pancreatic beta cells and activated upon stimulation with insulin-like growth factor I
Författare
Summary, in English
Protein kinase B (PKB) is involved in signaling to a multitude of important cellular events and is activated by insulin and growth factors, including insulin-like growth factor I (IGF-I). We show here expression of PKB in pancreatic islets and in the beta cell lines HIT-T15, INS-1, and RINm5F. Expression of PKB mRNA and the presence of PKB isoforms (alpha, beta, and gamma) were assessed by Northern blot analysis and RT-PCR, respectively. Antibodies recognizing different parts of PKB isoforms were employed to demonstrate PKB protein expression by immunoblot analysis. By use of immunohistochemistry in rat and mouse pancreatic tissue sections, PKB was localized to predominantly beta cells. Regulation of PKB was examined in INS-1 and RINm5F cells; upon stimulation with IGF-I (5-10 min), PKB was phosphorylated and activated (approximately 3-fold) by a wortmannin-sensitive mechanism, indicating involvement of phosphatidylinositol-3 kinase. The possible participation of PKB in signal transduction pathways modulating cAMP-dependent insulin secretion and in proliferation of beta cells is discussed.
Avdelning/ar
Publiceringsår
1998
Språk
Engelska
Sidor
181-186
Publikation/Tidskrift/Serie
Biochemical and Biophysical Research Communications
Volym
250
Issue
1
Dokumenttyp
Artikel i tidskrift
Förlag
Elsevier
Ämne
- Biological Sciences
Status
Published
Forskningsgrupp
- Insulin Signal Transduction
- Molecular Endocrinology
ISBN/ISSN/Övrigt
- ISSN: 1090-2104