Selective decrease of membrane-associated PKC-alpha and PKC-epsilon in response to elevated intracellular O-GlcNAc levels in transformed human glial cells.

Jason A Matthews; Mildred Acevedo-Duncan; Robert L Potter

doi:10.1016/j.bbamcr.2004.11.001

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PubMed · 15843043

Selective decrease of membrane-associated PKC-alpha and PKC-epsilon in response to elevated intracellular O-GlcNAc levels in transformed human glial cells.

Jason A Matthews·Mildred Acevedo-Duncan·Robert L Potter

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Abstract

Increased flux through the hexosamine biosynthetic pathway (HBP) has been shown to affect the activity and translocation of certain protein kinase C (PKC) isoforms. It has been suggested that this effect is due to increases in the beta-O-linked N-acetylglucosamine (O-GlcNAc) modification. Herein, we demonstrate the effect of increasing the O-GlcNAc modification on the translocation of select PKC isozymes in a human astroglial cell line. Treating cells with either 8 mM d-glucosamine (GlcN), 5 mM streptozotocin (STZ), or 80 muM O-(2-acetamido-2-deoxy-d-glucopyranosylidene)amino-N-phenylcarbamate (PUGNAc) produced a significant increase in the O-GlcNAc modification on both cytosolic and membrane proteins; however, both the level and rate of O-GlcNAc increase varied with the compound. GlcN treatment resulted in a rapid, transient translocation of PKC-betaII that was maximal after 3 h (73+/-8%) and also produced a 48+/-15% decrease in membrane-associated PKC-epsilon after 9 h of treatment. Similar to GlcN treatment, STZ and PUGNAc treatment also resulted in decreased levels of PKC-epsilon in the membrane fraction. Significant decreases were seen as early as 5 h and, by 9 h of treatment, had decreased by 87+/-6% with STZ and 73+/-7% with PUGNAc. Unlike GlcN, both STZ and PUGNAc produced a decrease in PKC-alpha membrane levels by 9 h posttreatment (78+/-10% with STZ and 66+/-8% with PUGNAc) while neither compound produced any changes in PKC-betaII translocation. In addition, none of the three compounds affected membrane levels of PKC-iota. Altogether, these results demonstrate a novel link between increased levels of the O-GlcNAc modification and the regulation of specific PKC isoforms.

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Acetylglucosamine Cell Line, Transformed Cell Membrane Cytosol Electrophoresis, Polyacrylamide Gel Glucosamine Humans Immunoblotting N-Acetylglucosaminyltransferases Neuroglia Oximes Phenylcarbamates Protein Kinase C Protein Kinase C-alpha Protein Kinase C-epsilon Streptozocin Journal Article

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Jason A Matthews, Mildred Acevedo-Duncan, Robert L Potter. 2004-12-02. Selective decrease of membrane-associated PKC-alpha and PKC-epsilon in response to elevated intracellular O-GlcNAc levels in transformed human glial cells.. https://doi.org/10.1016/j.bbamcr.2004.11.001

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