Expression and protein interaction analysis of the START family protein Rv0164 in Mycobacterium smegmatis

Abstract:

[Objective] Mutations or abnormal expressions of START family proteins in mammals are the basis for diseases such as adrenal hyperplasia, breast cancer and colon cancer. START family proteins are key regulators of plant development. The mechanism of the essential START proteins in prokaryote is unclear. Rv0164 belongs to the START family and is an essential gene with unknown function in Mycobacterium tuberculosis. Therefore, exploring the function of Rv0164 will add a new theory to the molecular mechanisms of START family.[Methods] Bioinformatics method was used to analyze the sequence of Rv0164. Rv0164 was expressed in the model strain Mycobacterium smegmatis and analyzed the protein localization. The interaction proteins of Rv0164 were identified by Co-IP and mass spectrometry, then verified by yeast two hybrid and pull down.[Results] The N-terminal 17 residues of Rv0164 were not conserved in Mycobacterium. Rv0164 had no signal peptide. Rv0164 was localized in cytoplasm and regulated by some proteostasis mechanisms which were weaker in stationary phase than in logarithmic phase. Deletion of the N-terminus of Rv0164 produced protein instability in both stationary phase and logarithmic phase. Rv0164 interacted with several cytosolic proteins.[Conclusion] The N-terminus of Rv0164 enhances protein stability. Rv0164 localizes in cytoplasm and can bind essential proteins.

Key words:START family;Rv0164;protein localization;protein-protein interaction