title: Helix insertion into bilayers and the evolution of membrane proteins.
abstract: Polytopic alpha-helical membrane proteins cannot spontaneously insert into lipid bilayers without assistance from polytopic alpha-helical membrane proteins that already reside in the membrane. This raises the question of how these proteins evolved. Our current knowledge of the insertion of alpha-helices into natural and model membranes is reviewed with the goal of gaining insight into the evolution of membrane proteins. Topics include: translocon-dependent membrane protein insertion, antibiotic peptides and proteins, in vitro insertion of membrane proteins, chaperone-mediated insertion of transmembrane helices, and C-terminal tail-anchored (TA) proteins. Analysis of the E. coli genome reveals several predicted C-terminal TA proteins that may be descendents of proteins involved in pre-cellular membrane protein insertion. Mechanisms of pre-translocon polytopic alpha-helical membrane protein insertion are discussed.
authors.affiliation: Department of Biology, University of Texas at San Antonio, 1 UTSA Circle, San Antonio, TX, 78249, USA. Robert.Renthal@UTSA.edu
authors.forename: Robert
authors.initials: R
authors.lastname: Renthal
mesh_terms: D000595:Amino Acid Sequence; D001430:Bacteriocins / Q000378:metabolism; D002135:Calcium-Binding Proteins / Q000378:metabolism; D002462:Cell Membrane / Q000737:chemistry / Q000378:metabolism*; D019143:Evolution, Molecular; D008051:Lipid Bilayers / Q000737:chemistry / Q000378:metabolism; D008562:Membrane Glycoproteins / Q000378:metabolism; D008565:Membrane Proteins / Q000737:chemistry* / Q000378:metabolism; D018832:Molecular Chaperones / Q000378:metabolism; D008969:Molecular Sequence Data; D017433:Protein Structure, Secondary; D018160:Receptors, Cytoplasmic and Nuclear / Q000378:metabolism; D018000:Receptors, Peptide / Q000378:metabolism
chemical_list: D001430:Bacteriocins; D002135:Calcium-Binding Proteins; D008051:Lipid Bilayers; D008562:Membrane Glycoproteins; D008565:Membrane Proteins; D018832:Molecular Chaperones; D018160:Receptors, Cytoplasmic and Nuclear; D018000:Receptors, Peptide; C066973:signal sequence receptor