Ras-Related Protein Rab-7a Regulates Glucose Metabolism under Hypoxia by Interacting with Hypoxia-Inducible Factor 1-Alpha in HepG2 Cells

Ras-related protein Rab-7a (RAB7A) is a member of the RAS oncogene superfamily; it plays an important role in vesicle transport. In this study, we described the mechanism of RAB7A-dependent regulation of glucose metabolism in HepG2 cells under hypoxia. We found that RAB7A increases lactate production, adenosine 5'-triphosphate (ATP) production, and glycogen content in HepG2 cells under hypoxia. RAB7A also stimulates the expression of fructose-bisphosphate aldolase A (ALDOA), an enzyme involved in glucose metabolism. Furthermore, we discovered that RAB7A protein binds to hypoxia-inducible factor 1‑alpha (HIF1A) protein to enhance its binding to ALDOA promoter and elevate expression of ALDOA and promote glycolysis and glycogenesis. Notably, RAB7A and HIF1A did not interfere with each other. These observations preliminarily explain the molecular mechanism by which RAB7A exerts its role in regulating glucose metabolism in HepG2 under hypoxia. Our work may provide a potential direction for studying RAB7A in liver diseases.