Barbakadze T, Goloshvili G, Narmania N, Zhuravliova E, Mikeladze D. Subcellular Distribution of S-Nitrosylated H-Ras in Differentiated and Undifferentiated PC12 Cells during Hypoxia.
CELL JOURNAL 2017;
19:443-451. [PMID:
28836406 PMCID:
PMC5570409 DOI:
10.22074/cellj.2017.4546]
[Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/19/2016] [Accepted: 11/07/2016] [Indexed: 12/30/2022]
Abstract
Objective
Hypoxia or exposure to excessive reactive oxygen or nitrogen species could
induce S-nitrosylation of various target proteins, including GTPases of the Ras-superfamily. Under hypoxic conditions, the Ras-protein is translocated to the cytosol and interacts
with the Golgi complex, endoplasmic reticulum, mitochondria. The mobility/translocation
of Ras depend on the cells oxidative status. However, the importance of relocated S-nitrosylated-H-Ras (NO-H-Ras) in proliferation/differentiation processes is not completely
understood. We have determined the content of soluble- and membrane-bound-NO-H-Ras in differentiated (D) and undifferentiated (ND) rat pheochromocytoma (PC12) cells
under hypoxic and normoxic conditions.
Materials and Methods
In our experimental study, we analyzed NO-H-Ras levels under hypoxic/normoxic conditions in membrane and soluble fractions of ND and D PC12
cells with/without nitric oxide donor, sodium nitroprusside (SNP) treatment. Cells were
analyzed by the S-nitrosylated kit, immunoprecipitation, and Western blot. We assessed
the action of NO-H-Ras on oxidative metabolism of isolated mitochondria by determining
mitochondrial hydrogen peroxide generation via the scopoletin oxidation method and ATP-production as estimated by the luminometric method.
Results
Hypoxia did not influence nitrosylation of soluble H-Ras in ND PC12 cells. Under hypoxic conditions, the nitrosylation of soluble-H-Ras greatly decreased in D PC12
cells. SNP didn’t change the levels of nitrosylation of soluble-H-Ras, in either hypoxic
or normoxic conditions. On the other hand, hypoxia, per se, did not affect the nitrosylation of membrane-bound-H-Ras in D and ND PC12 cells. SNP-dependent nitrosylation of
membrane-bound-H-Ras greatly increased in D PC12 cells. Both unmodified normal and
mutated H-Ras enhanced the mitochondrial synthesis of ATP, whereas the stimulatory effects on ATP synthesis were eliminated after S-nitrosylation of H-Ras.
Conclusion
According to the results, it may be proposed that hypoxia can decrease
S-nitrosylation of soluble-H-Ras in D PC12 cells and abolish the inhibitory effect of NO-H-Ras in mitochondrial oxidative metabolism.
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