Nucleocytoplasmic shuttling of hexokinase II in a cancer cell
- Department of Molecular Biology, School of Osteopathic Medicine, University of Medicine and Dentistry of New Jersey, Stratford, NJ 08084 (United States)
In yeast, the hexokinase type II enzyme (HXKII) translocates to the nucleus in the presence of excess glucose, and participates in glucose repression. However, no evidence has suggested a nuclear function for HXKII in mammalian cells. Herein, we present data showing nuclear localization of HXKII in HeLa cells, both by immunocytochemistry and subcellular fractionation. HXKII is extruded from the nucleus, at least in part, by the activity of the exportin 1/CrmA system, as demonstrated by increased nuclear expression and decreased cytoplasmic expression after incubation with leptomycin B, a bacterially-derived exportin inhibitor. Furthermore, cytoplasmic localization of HXKII is dependent on its enzymatic activity, as inhibiting HXKII activity using 2-deoxy-D-glucose (2DG) increased nuclear localization. This effect was more significant in cells incubated in the absence of glucose for 24 h prior to addition of 2DG. Regulated translocation of HXKII to the nucleus of mammalian cells could represent a previously unknown glucose-sensing mechanism.
- OSTI ID:
- 22202487
- Journal Information:
- Biochemical and Biophysical Research Communications, Vol. 394, Issue 4; Other Information: Copyright (c) 2010 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA); ISSN 0006-291X
- Country of Publication:
- United States
- Language:
- English
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