Identification of Mitogen-activated Protein Kinase from Schizochytrium sp. and Application in Resisting Stress Environments

Abstract: Schizochytrium sp. is a marine fungus, which usually lives in the salinity of 40–100% seawater and has unique salt tolerance characteristics. In this study, we explored the candidate mitogen-activated protein kinase (MAPK) related to the salt-tolerant regulatory network from Schizochytrium sp. Firstly, 6 potential MAPK genes from Schizochytrium sp. were identified based on the genome information and bioinformatics analysis. Then, the MAPK gene expression of Schizochytrium sp. under different cultivation conditions locked two genes encoding Mpk6315 and Mpk2022. Furthermore, overexpressing of Mpk6315 in S. cerevisiae enhanced cell growth by 62% while and Mpk2022 overexpression improved the membrane integrity under different stress conditions, indicating that Mpk6315 might play an important role for cell growth and Mpk2022 could help cells to encounter different environmental stressors. This study was the first time to identify the MAPK genes from Schizochytrium sp., which could enlarge the MAPK modules of salt stress tolerance and provide new elements for improving the stress resistance of other microorganisms.