Quantitative proteomics reveals novel interaction partners of Rac1 in pancreatic β-cells: Evidence for increased interaction with Rac1 under hyperglycemic conditions. (20th August 2019)

• Record Type: Journal Article
• Authors: Damacharla, Divyasri; Thamilselvan, Vijayalakshmi; Zhang, Xiangmin; Mestareehi, Aktham; Yi, Zhengping; Kowluru, Anjaneyulu
• Is Part Of: Molecular and cellular endocrinology. Volume 494(2019)
• Publication Date: 2019-08-20
• Subjects: Rac1 -- Pancreatic β-cell -- Hyperglycemic conditions -- Proteomics -- Protein-protein interactions -- UPLC-ESI-MS/MS -- Insulin secretion -- Apoptosis -- Diabetes mellitus; Endocrinology -- Periodicals; Molecular biology -- Periodicals; Cytology -- Periodicals; Endocrinology -- Periodicals; Hormones -- Periodicals; Endocrinologie -- Périodiques; Cytology; Endocrinology; Molecular biology; Periodicals; 573.4
• DOI: 10.1016/j.mce.2019.110489
• Languages: English
• ISSNs: 0303-7207

Abstract

Abstract: Rac1, a small G protein, regulates physiological insulin secretion from the pancreatic β-cell. Interestingly, Rac1 has also been implicated in the onset of metabolic dysfunction of the β-cell under the duress of hyperglycemia (HG). This study is aimed at the identification of interaction partners of Rac1 in β-cells under basal and HG conditions. Using co-immunoprecipitation and UPLC-ESI-MS/MS, we identified 324 Rac1 interaction partners in INS-1832/13 cells, which represent the largest Rac1 interactome to date. Furthermore, we identified 27 interaction partners that exhibited increased association with Rac1 in β-cells exposed to HG. Western blotting (INS-1832/13 cells, rat islets and human islets) and co-immunoprecipitation (INS-1832/13 cells) further validated the identity of these Rac1 interaction partners including regulators of GPCR-G protein-effector coupling in the islet. These data form the basis for future investigations on contributory roles of these Rac1-specific signaling pathways in islet β-cell function in health and diabetes. Graphical abstract: Image 1 Highlights: This study identified 324 Rac1 interaction partners in INS-1832/13 cells. It represents the largest Rac1 interactome to date. Association of 27 of these with Rac1 was increased under hyperglycemic conditions. Proteomics findings are validated by immunoblotting in rat islets and human islets. Roles of Rac1 interactome in β-cell function in health and diabetes are discussed.