title: Folding of newly translated membrane protein CCR5 is assisted by the chaperonin GroEL-GroES.
abstract: The in vitro folding of newly translated human CC chemokine receptor type 5 (CCR5), which belongs to the physiologically important family of G protein-coupled receptors (GPCRs), has been studied in a cell-free system supplemented with the surfactant Brij-35. The freshly synthesized CCR5 can spontaneously fold into its biologically active state but only slowly and inefficiently. However, on addition of the GroEL-GroES molecular chaperone system, the folding of the nascent CCR5 was significantly enhanced, as was the structural stability and functional expression of the soluble form of CCR5. The chaperonin GroEL was partially effective on its own, but for maximum efficiency both the GroEL and its GroES lid were necessary. These results are direct evidence for chaperone-assisted membrane protein folding and therefore demonstrate that GroEL-GroES may be implicated in the folding of membrane proteins.
authors.affiliation: State Key Laboratory of Heavy Oil Processing and Center for Bioengineering and Biotechnology, China University of Petroleum (East China), Qingdao 266580, P. R. China.
authors.forename: Haixia
authors.initials: H
authors.lastname: Chi
authors.affiliation: State Key Laboratory of Heavy Oil Processing and Center for Bioengineering and Biotechnology, China University of Petroleum (East China), Qingdao 266580, P. R. China.
authors.forename: Xiaoqiang
authors.initials: X
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Heavy Oil Processing and Center for Bioengineering and Biotechnology, China University of Petroleum (East China), Qingdao 266580, P. R. China.
authors.forename: Jiqiang
authors.initials: J
authors.lastname: Li
authors.affiliation: State Key Laboratory of Heavy Oil Processing and Center for Bioengineering and Biotechnology, China University of Petroleum (East China), Qingdao 266580, P. R. China.
authors.forename: Hao
authors.initials: H
authors.lastname: Ren
authors.affiliation: State Key Laboratory of Heavy Oil Processing and Center for Bioengineering and Biotechnology, China University of Petroleum (East China), Qingdao 266580, P. R. China.
authors.forename: Fang
authors.initials: F
authors.lastname: Huang
mesh_terms: D015153:Blotting, Western; D018835:Chaperonin 10 / Q000737:chemistry* / Q000378:metabolism; D018834:Chaperonin 60 / Q000737:chemistry* / Q000378:metabolism; D006801:Humans; D008565:Membrane Proteins / Q000737:chemistry* / Q000378:metabolism; D008958:Models, Molecular; D011485:Protein Binding; D011487:Protein Conformation; D017510:Protein Folding; D055550:Protein Stability; D019713:Receptors, CCR5 / Q000737:chemistry* / Q000378:metabolism
chemical_list: D018835:Chaperonin 10; D018834:Chaperonin 60; D008565:Membrane Proteins; D019713:Receptors, CCR5