Protein kinase B is expressed in pancreatic β cells and activated upon stimulation with insulin-like growth factor I
LS Holst, H Mulder, V Manganiello, F Sundler… - Biochemical and …, 1998 - Elsevier
LS Holst, H Mulder, V Manganiello, F Sundler, B Ahrén, C Holm, E Degerman
Biochemical and biophysical research communications, 1998•ElsevierProtein 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 β cell lines HIT-T15, INS-1, and
RINm5F. Expression of PKB mRNA and the presence of PKB isoforms (α, β, and γ) 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 …
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 β cell lines HIT-T15, INS-1, and
RINm5F. Expression of PKB mRNA and the presence of PKB isoforms (α, β, and γ) 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 …
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 β cell lines HIT-T15, INS-1, and RINm5F. Expression of PKB mRNA and the presence of PKB isoforms (α, β, and γ) 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 β 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 (≈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 β cells is discussed.
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