O-GlcNAc modification of proteins affects volume regulation in Jurkat cells.
An increasing amount of recent research has demonstrated that the hexosamine biosynthesis pathway (HBP) plays a significant role in the modulation of intracellular signaling transduction pathways, and affects cellular processes via modification of protein by O-linked beta-N-acetylglucosamine (O-GlcNAc). Besides the many known and postulated effects of protein O-GlcNAc modifications, there is little available data on the role of O-GlcNAc in cellular volume regulation. Our objective was to test the effect of increased O-GlcNAc levels on hypotonia-induced volume changes in Jurkat cells. We pretreated Jurkat cells for 1 h with glucosamine (GlcN), PUGNAc (O-(2-acetamido-2-deoxy-D-glucopyranosylidene)-amino-N-phenylcarbamate) an inhibitor of O-GlcNAcase, or a high level of glucose to induce elevated levels of O-GlcNAc. We found that the response of Jurkat cells to hypotonic stress was significantly altered. The hypotonia induced cell-swelling was augmented in both GlcN and PUGNAc-treated cells and, to a lesser extent, in high glucose concentration-treated cells. Evaluated by NMR measurements, GlcN and PUGNAc treatment also significantly reduced intracellular water diffusion. Taken together, increased cell swelling and reduced water diffusion caused by elevated O-GlcNAc show notable analogy to the regulatory volume changes seen by magnetic resonance methods in nervous and other tissues in different pathological states. In conclusion, we demonstrate for the first time that protein O-GlcNAc could modulate cell volume regulation.
Nagy
Tamás
T
Department of Laboratory Medicine, Faculty of Medicine, University of Pécs, Ifjúság str. 13, 7624, Pecs, Hungary.
Balasa
Alfréd
A
Frank
Dorottya
D
Rab
András
A
Rideg
Orsolya
O
Kotek
Gyula
G
Magyarlaki
Tamás
T
Bogner
Péter
P
Kovács
Gábor L
GL
Miseta
Attila
A
D000117:Acetylglucosamine / Q000031:analogs & derivatives / Q000378:metabolism* / Q000494:pharmacology; D017209:Apoptosis / Q000502:physiology; D015153:Blotting, Western; D002453:Cell Cycle; D002462:Cell Membrane / Q000502:physiology; D048429:Cell Size / Q000187:drug effects; D004058:Diffusion; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005453:Fluorescence; D005947:Glucose / Q000378:metabolism; D006031:Glycosylation; D006801:Humans; D042541:Intracellular Space / Q000378:metabolism; D019169:Jurkat Cells; D019906:Nuclear Magnetic Resonance, Biomolecular; D010091:Oximes / Q000494:pharmacology; D048448:Phenylcarbamates / Q000494:pharmacology; D013312:Stress, Physiological / Q000502:physiology; D013997:Time Factors; D014867:Water / Q000378:metabolism
D004791:Enzyme Inhibitors; D010091:Oximes; D048448:Phenylcarbamates; D014867:Water; C068836:N-acetylglucosaminono-1,5-lactone O-(phenylcarbamoyl)oxime; D005947:Glucose; D000117:Acetylglucosamine