TY - JOUR
T1 - Phospholipid activation of the insulin receptor kinase
T2 - Regulation by phosphatidylinositol
AU - Sweet, L. J.
AU - Dudley, D. T.
AU - Pessin, J. E.
AU - Spector, A. A.
N1 - Copyright:
Copyright 2020 Elsevier B.V., All rights reserved.
PY - 1987
Y1 - 1987
N2 - A soybean phospholipid mixture produced a concentration-dependent enhancement of β subunit autophosphorylation of the detergent-soluble, purified human placental insulin receptor. Although phosphatidylcholine, phosphatidylethanolamine, or phosphatidylserine also increased insulin receptor autophosphorylation, only phosphatidylinositol (PtdIns) stimulated to a similar extent as the phospholipid mixture. The effect of PtdIns was biphasic, stimulating at low concentrations (75 μM), but having no stimulatory effect at high concentrations (1.0 mM). Phospholipids also stimulated the exogenous protein kinase activity of the insulin receptor toward histone H2B. Phosphorylation of PtdIns occurrd with these purified insulin receptor preparations, but this activity was insulin-independent, and the turnover number for PtdIns phosphorylation in the presence of soybean phospholipid was 1/220th as small as the turnover number for the autophosphorylating activity. These results suggest that although PtdIns can modulate the activity of the insulin receptor kinase, PtdIns phosphorylation itself is not directly involved in this regulation.
AB - A soybean phospholipid mixture produced a concentration-dependent enhancement of β subunit autophosphorylation of the detergent-soluble, purified human placental insulin receptor. Although phosphatidylcholine, phosphatidylethanolamine, or phosphatidylserine also increased insulin receptor autophosphorylation, only phosphatidylinositol (PtdIns) stimulated to a similar extent as the phospholipid mixture. The effect of PtdIns was biphasic, stimulating at low concentrations (75 μM), but having no stimulatory effect at high concentrations (1.0 mM). Phospholipids also stimulated the exogenous protein kinase activity of the insulin receptor toward histone H2B. Phosphorylation of PtdIns occurrd with these purified insulin receptor preparations, but this activity was insulin-independent, and the turnover number for PtdIns phosphorylation in the presence of soybean phospholipid was 1/220th as small as the turnover number for the autophosphorylating activity. These results suggest that although PtdIns can modulate the activity of the insulin receptor kinase, PtdIns phosphorylation itself is not directly involved in this regulation.
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U2 - 10.1096/fasebj.1.1.3038645
DO - 10.1096/fasebj.1.1.3038645
M3 - Article
C2 - 3038645
AN - SCOPUS:0023605318
SN - 0892-6638
VL - 1
SP - 55
EP - 59
JO - FASEB Journal
JF - FASEB Journal
IS - 1
ER -