Glycosylated phosphatidylinositol (gly-Pl) molecules have been implicated as precursors for insulin-sensitive second messengers (1–4) and lipid-anchored membrane proteins (5–9). The relationship between the diverse functions of these lipids and their predicted structural heterogeneity within gly-Pl subtypes was examined in human T lymphocytes. Four subtypes of gly-Pl molecules were identified in T lymphocytes after separation over high-performance thin-layer chromatography by sensitivity to Pl-specific phospholipase C and nitrous acid. Antibody probes of the glycan domain of gly-Pl were developed and used to assess the partial sensitivity of gly-Pl to insulin action. This analysis showed that the effects of insulin are linked to differential utilization of only two of the four gly-Pl subtypes in T lymphocytes. Polar fragments of this reaction were identified in extracellular supernatants from insulin-treated cells. The biological significance of insulin-dependent gly-Pl hydrolysis was demonstrated by insulin and inositol phosphoglycan regulation of glucose metabolism in intact lymphocytes. These results support the hypothesis that multifunctional roles of gly-Pl are served by discrete gly-Pl populations and that metabolites of gly-Pl subsets participate as signaling elements in insulin action.
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Original Articles| October 01 1991
Differential Regulation of Glycosylated Phosphatidylinositol Subtypes by Insulin
Address correspondence and reprint requests to Dr. Glen N. Gaulton, Department of Pathology and Laboratory Medicine, Division of Immunobiology, University of Pennsylvania School of Medicine, Philadelphia, PA 19104.
Glen N Gaulton; Differential Regulation of Glycosylated Phosphatidylinositol Subtypes by Insulin. Diabetes 1 October 1991; 40 (10): 1297–1304. https://doi.org/10.2337/diab.40.10.1297
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