Abstract
Using siRNA-mediated gene silencing in cultured adipocytes, we have dissected the insulin-signalling pathway leading to translocation of GLUT4 glucose transporters to the plasma membrane. RNAi (RNA interference)-based depletion of components in the putative TC10 pathway (CAP, CrkII and c-Cbl plus Cbl-b) or the phospholipase Cγ pathway failed to diminish insulin signalling to GLUT4. Within the phosphoinositide 3-kinase pathway, loss of the 5′-phosphatidylinositol 3,4,5-trisphosphate phosphatase SHIP2 was also without effect, whereas depletion of the 3′-phosphatase PTEN significantly enhanced insulin action. Downstream of phosphatidylinositol 3,4,5-trisphosphate and PDK1, silencing the genes encoding the protein kinases Akt1/PKBα, or CISK(SGK3) or protein kinases Cλ/ζ had little or no effect, but loss of Akt2/PKBβ significantly attenuated GLUT4 regulation by insulin. These results show that Akt2/PKBβ is the key downstream intermediate within the phosphoinositide 3-kinase pathway linked to insulin action on GLUT4 in cultured adipocytes, whereas PTEN is a potent negative regulator of this pathway.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 817-821 |
| Number of pages | 5 |
| Journal | Biochemical Society Transactions |
| Volume | 32 |
| Issue number | 5 |
| DOIs | |
| State | Published - Nov 1 2004 |
| Externally published | Yes |
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Keywords
- Gene silencing
- Glucose
- Insulin signalling
- Phosphoinositide 3-kinase (PI3K)
- Phospholipase Cγ
- Protien kinase Cλ/ζ siRNA
ASJC Scopus subject areas
- Biochemistry
Cite this
Analysis of insulin signalling by RNAi-based gene silencing. / Zhou, Q. I.; Park, Jin; Jiang, Z. Y.; Holik, J. J.; Mitra, P.; Semiz, S.; Guilherme, A.; Powelka, A. M.; Tang, X.; Virbasius, J.; Czech, M. P.
In: Biochemical Society Transactions, Vol. 32, No. 5, 01.11.2004, p. 817-821.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Analysis of insulin signalling by RNAi-based gene silencing
AU - Zhou, Q. I.
AU - Park, Jin
AU - Jiang, Z. Y.
AU - Holik, J. J.
AU - Mitra, P.
AU - Semiz, S.
AU - Guilherme, A.
AU - Powelka, A. M.
AU - Tang, X.
AU - Virbasius, J.
AU - Czech, M. P.
PY - 2004/11/1
Y1 - 2004/11/1
N2 - Using siRNA-mediated gene silencing in cultured adipocytes, we have dissected the insulin-signalling pathway leading to translocation of GLUT4 glucose transporters to the plasma membrane. RNAi (RNA interference)-based depletion of components in the putative TC10 pathway (CAP, CrkII and c-Cbl plus Cbl-b) or the phospholipase Cγ pathway failed to diminish insulin signalling to GLUT4. Within the phosphoinositide 3-kinase pathway, loss of the 5′-phosphatidylinositol 3,4,5-trisphosphate phosphatase SHIP2 was also without effect, whereas depletion of the 3′-phosphatase PTEN significantly enhanced insulin action. Downstream of phosphatidylinositol 3,4,5-trisphosphate and PDK1, silencing the genes encoding the protein kinases Akt1/PKBα, or CISK(SGK3) or protein kinases Cλ/ζ had little or no effect, but loss of Akt2/PKBβ significantly attenuated GLUT4 regulation by insulin. These results show that Akt2/PKBβ is the key downstream intermediate within the phosphoinositide 3-kinase pathway linked to insulin action on GLUT4 in cultured adipocytes, whereas PTEN is a potent negative regulator of this pathway.
AB - Using siRNA-mediated gene silencing in cultured adipocytes, we have dissected the insulin-signalling pathway leading to translocation of GLUT4 glucose transporters to the plasma membrane. RNAi (RNA interference)-based depletion of components in the putative TC10 pathway (CAP, CrkII and c-Cbl plus Cbl-b) or the phospholipase Cγ pathway failed to diminish insulin signalling to GLUT4. Within the phosphoinositide 3-kinase pathway, loss of the 5′-phosphatidylinositol 3,4,5-trisphosphate phosphatase SHIP2 was also without effect, whereas depletion of the 3′-phosphatase PTEN significantly enhanced insulin action. Downstream of phosphatidylinositol 3,4,5-trisphosphate and PDK1, silencing the genes encoding the protein kinases Akt1/PKBα, or CISK(SGK3) or protein kinases Cλ/ζ had little or no effect, but loss of Akt2/PKBβ significantly attenuated GLUT4 regulation by insulin. These results show that Akt2/PKBβ is the key downstream intermediate within the phosphoinositide 3-kinase pathway linked to insulin action on GLUT4 in cultured adipocytes, whereas PTEN is a potent negative regulator of this pathway.
KW - Gene silencing
KW - Glucose
KW - Insulin signalling
KW - Phosphoinositide 3-kinase (PI3K)
KW - Phospholipase Cγ
KW - Protien kinase Cλ/ζ siRNA
UR - http://www.scopus.com/inward/record.url?scp=8744305112&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=8744305112&partnerID=8YFLogxK
U2 - 10.1042/BST0320817
DO - 10.1042/BST0320817
M3 - Article
C2 - 15494023
AN - SCOPUS:8744305112
VL - 32
SP - 817
EP - 821
JO - Biochemical Society Transactions
JF - Biochemical Society Transactions
SN - 0300-5127
IS - 5
ER -