Cuijuan Shi1, Hong Zhang1, Kai Yu1, Yingying Wang2, Jie Jiang1,3, Yun Ju1, Chuanzhou Zhang1, Ziyi Cheng1, Guangfeng Kan4,5. 1. School of Marine Science and Technology, Harbin Institute of Technology at Weihai, Weihai, 264209, China. 2. Department of Optoelectronic Science, Harbin Institute of Technology at Weihai, Weihai, 264209, People's Republic of China. 3. State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin, Heilongjiang, 150090, People's Republic of China. 4. School of Marine Science and Technology, Harbin Institute of Technology at Weihai, Weihai, 264209, China. gfkan@hit.edu.cn. 5. State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin, Heilongjiang, 150090, People's Republic of China. gfkan@hit.edu.cn.
Abstract
BACKGROUND: The mitogen-activated protein kinase (MAPK) cascades play important roles in various signaling transduction networks of biotic and abiotic stress responses. However, MAPK signaling pathways in cold-active yeast Rhodotorula mucilaginosa have not been reported comprehensively. METHODS AND RESULTS: In the present study, MAPK gene (RmMAPK) was first cloned and characterized from Antarctic sea ice yeast R. mucilaginosa AN5. The full length of the RmMAPK gene is 1086 bp and encodes a 361 amino acids protein with a predicted molecular mass of 40.9 kDa and a pI of 5.25. The RmMAPK contains 11 MAPK conserved subdomains and the phosphorylation motif TGY located in the activation loop of the kinase. Quantitative real-time PCR and western blot assay revealed that the expression and phosphorylation level of RmMAPK up-regulated rapidly and significantly when yeast cells were subjected to low temperature (4 °C), high salinity (120‰ NaCl) and heavy metal (2 mmol/L CuCl2). CONCLUSIONS: All data suggested that the MAPK cascades might act as a key function in response to extreme stresses, such as low temperature, high salinity and heavy metal.
BACKGROUND: The mitogen-activated protein kinase (MAPK) cascades play important roles in various signaling transduction networks of biotic and abiotic stress responses. However, MAPK signaling pathways in cold-active yeast Rhodotorula mucilaginosa have not been reported comprehensively. METHODS AND RESULTS: In the present study, MAPK gene (RmMAPK) was first cloned and characterized from Antarctic sea ice yeast R. mucilaginosa AN5. The full length of the RmMAPK gene is 1086 bp and encodes a 361 amino acids protein with a predicted molecular mass of 40.9 kDa and a pI of 5.25. The RmMAPK contains 11 MAPK conserved subdomains and the phosphorylation motif TGY located in the activation loop of the kinase. Quantitative real-time PCR and western blot assay revealed that the expression and phosphorylation level of RmMAPK up-regulated rapidly and significantly when yeast cells were subjected to low temperature (4 °C), high salinity (120‰ NaCl) and heavy metal (2 mmol/L CuCl2). CONCLUSIONS: All data suggested that the MAPK cascades might act as a key function in response to extreme stresses, such as low temperature, high salinity and heavy metal.