title: Endoplasmic reticulium protein profiling of heat-stressed Jurkat cells by one dimensional electrophoresis and liquid chromatography tandem mass spectrometry.
abstract: Proteomic study on membrane-integrated proteins in endoplasmic reticulum (ER) fractions was performed. In this study, we examined the effects of heat stress on Jurkat cells. The ER fractions were highly purified by differential centrifugation with sodium carbonate washing and acetone methanol precipitations. The ER membrane proteins were separated by one dimensional electrophoresis (1-DE), and some of the protein bands changed their abundance by heat stress, 12 of the 14 bands containing 40 and 60 ribosomal proteins whose expression level were decreased, on the contrary, 2 of the 14 bands containing ubiquitin and eukaryotic translation initiation factor 3 were increased. Heat treatment of human Jurkat cells led to an increase in the phosphorylation of PERK and eIF2α within 30 min of exposure. This was followed by an increase in the expression of the GRP78. Protein ubiquitination and subsequent degradation by the proteasome are important mechanisms regulating cell cycle, growth and differentiation, the result showed that heat stress enhanced ubiquitination modification of the microsomal proteins. The data of this study strongly suggest that heat treatment led to a significant reduction in protein expression and activated UPR, concomitant with protein hyperubiqutination in ER.
authors.affiliation: The Institute of Human Nutrition, Medical College of Qingdao University, Dengzhou Road 38, Qingdao, 266021, People's Republic of China. zhangliulian@hotmail.com.|Qingdao Center for Disease Control and Prevention, Qingdao, 266032, People's Republic of China. zhangliulian@hotmail.com.
authors.forename: Xiulian
authors.initials: X
authors.lastname: Zhang
authors.affiliation: Department of Biochemistry and Functional Proteomics, Yamaguchi University Graduate School of Medicine, Ube, 755-8505, Japan.
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Kuramitsu
authors.affiliation: The Institute of Human Nutrition, Medical College of Qingdao University, Dengzhou Road 38, Qingdao, 266021, People's Republic of China.
authors.forename: Aiguo
authors.initials: A
authors.lastname: Ma
authors.affiliation: Zaozhuang University Hospital, Beian Road 1, Zaozhuang, 277160, People's Republic of China.
authors.forename: Hui
authors.initials: H
authors.lastname: Zhang
authors.affiliation: Department of Biochemistry and Functional Proteomics, Yamaguchi University Graduate School of Medicine, Ube, 755-8505, Japan.
authors.forename: Kazuyuki
authors.initials: K
authors.lastname: Nakamura
keywords: Endoplasmic reticulium; Heat stress; LC–MS/MS; SDS-PAGE