Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
10751759 | Biochemical and Biophysical Research Communications | 2015 | 7 Pages |
Abstract
Upon shift to a hypoxic environment, cellular HIF-1α protein is stabilized, with a rapid decline in oxygen-sensitive hydroxylation. Several additional post-translational modifications of HIF-1α are critical in controlling protein stability during hypoxia. In the present study, we showed that SIRT1 stabilizes HIF-1α via direct binding and deacetylation during hypoxia. SIRT1 depletion or inactivation led to reduced hypoxic HIF-1α accumulation, accompanied by an increase in HIF-1α acetylation. Impaired HIF-1α accumulation was recovered upon inhibition of 26S proteasome activity, indicating that SIRT1 is essential for HIF-1α stabilization during hypoxia. Consistently, HIF-1α accumulation was enhanced upon overexpression of wild-type SIRT1, but not its dominant-negative form. SIRT1-mediated accumulation of HIF-1α protein led to increased expression of HIF-1α target genes, including VEGF, GLUT1 and MMP2, and ultimate promotion of cancer cell invasion. These findings collectively imply that hypoxic HIF-1α stabilization requires SIRT1 activation. Furthermore, SIRT1 protection of HIF-1α from acetylation may be a prerequisite for stabilization and consequent enhancement of cell invasion.
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Authors
Hyun-Yoo Joo, Miyong Yun, Jaemin Jeong, Eun-Ran Park, Hyun-Jin Shin, Seon Rang Woo, Jin Kyu Jung, Yong-Min Kim, Joong-Jean Park, Joon Kim, Kee-Ho Lee,