title: Proteomic insights into the temperature responses of a cold-adaptive archaeon Methanolobus psychrophilus R15.
abstract: Cold-adaptive methanogens contribute significantly to methane emission from the cold area, while the cold-adaptive mechanisms used by Archaea remain elusive. Methanolobus psychrophilus R15, a cold-adaptive methanogen isolated from a Tibetan plateau wetland, grows at 0-25 °C and optimally at 18 °C when isolated; however, it grows optimally at 30 °C after culturing at 18 °C for several years. Aiming to gain insights into the protein profiles that are involved in optimal growth and cold adaptation of this methanogen, here, we performed a comparative proteomic study using 2D DIGE on the cultures grown at 30, 18 and 4 °C. 1439 protein spots (3167 ORFs annotated in the R15 genome) were detected, and 202 of 322 differentially expressed protein spots were identified by MALDI-TOF/TOF. The protein abundance of most enzymes involved in methanogenesis, energy conservation and central metabolism were increased at 30 °C, while most ribosome proteins were decreased at 30 °C. Proteasome and ROS scavengers increased expressions at 4 °C, suggesting more aberrant proteins and ROS formed at lower temperatures. Different from the cold-adaptive Methanococcoides burtonii, some chaperones were increased at 4 °C, implying that protein folding was impaired at cold in this psychrophilic archaeon. This study indicates that diverse cold-adaptive mechanisms can be used by different methanogenic Archaea.
authors.affiliation: State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, No. 1 Beichen West Road, Beijing, 100101, China.
authors.forename: Zijuan
authors.initials: Z
authors.lastname: Chen
authors.forename: Deqin
authors.initials: D
authors.lastname: Feng
authors.forename: Bo
authors.initials: B
authors.lastname: Zhang
authors.forename: Qian
authors.initials: Q
authors.lastname: Wang
authors.forename: Yuanming
authors.initials: Y
authors.lastname: Luo
authors.forename: Xiuzhu
authors.initials: X
authors.lastname: Dong
mesh_terms: D000222:Adaptation, Physiological; D019843:Archaeal Proteins / Q000235:genetics / Q000378:metabolism*; D003080:Cold Temperature; D058639:Cold-Shock Response; D008697:Methane / Q000378:metabolism; D017019:Methanosarcinaceae / Q000235:genetics / Q000378:metabolism*; D020543:Proteome
chemical_list: D019843:Archaeal Proteins; D020543:Proteome; D008697:Methane