title: Understanding integration of α-helical membrane proteins: the next steps.
abstract: Integration of a protein into the endoplasmic reticulum (ER) membrane occurs through a series of multistep reactions that include targeting of ribosome-nascent polypeptide complexes to the ER, attachment of the ribosome to the protein translocation channel, lateral partitioning of α-helical transmembrane spans into the lipid bilayer, and folding of the lumenal, cytosolic and membrane-embedded domains of the protein. However, the molecular mechanisms and kinetics of these steps are still not entirely clear. To obtain a better understanding of the mechanism of membrane protein integration, we propose that it will be important to utilize in vivo experiments to examine the kinetics of membrane protein integration and in vitro experiments to characterize interactions between nascent membrane proteins, protein translocation factors and molecular chaperones.
authors: Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, MA 01605-2324, USA. reid.gilmore@umassmed.edu
authors: Reid
authors: R
authors: Gilmore
authors: Elisabet C
authors: EC
authors: Mandon
mesh_terms: D003600:Cytosol / Q000737:chemistry; D018870:Endoplasmic Reticulum, Rough / Q000737:chemistry* / Q000235:genetics; D057927:Hydrophobic and Hydrophilic Interactions; D008565:Membrane Proteins / Q000737:chemistry* / Q000235:genetics; D026901:Membrane Transport Proteins / Q000737:chemistry / Q000235:genetics; D014176:Protein Biosynthesis; D017510:Protein Folding; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D021381:Protein Transport; D012331:RNA, Fungal / Q000737:chemistry* / Q000235:genetics; D012333:RNA, Messenger / Q000737:chemistry / Q000235:genetics; D012270:Ribosomes / Q000737:chemistry / Q000235:genetics; D000069816:SEC Translocation Channels; D012441:Saccharomyces cerevisiae / Q000737:chemistry / Q000235:genetics; D029701:Saccharomyces cerevisiae Proteins / Q000737:chemistry / Q000235:genetics
chemical_list: D008565:Membrane Proteins; D026901:Membrane Transport Proteins; D012331:RNA, Fungal; D012333:RNA, Messenger; D000069816:SEC Translocation Channels; C499383:SEC61 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins