Anthony Victoria, Skach William R
Division of Molecular Medicine, Oregon Health and Sciences University, 3181 SW Sam Jackson Park Rd., Portland, Oregon 97201, USA.
Curr Protein Pept Sci. 2002 Oct;3(5):485-501. doi: 10.2174/1389203023380503.
In the past decade major advances have been made towards understanding the mechanisms by which polytopic membrane proteins fold and assemble in cellular membranes. In eukaryotes, this process is mediated by a complex set of machinery in the endoplasmic reticulum (ER) that facilitates translocation of peptide loops across and integration of hydrophobic helices into the lipid bilayer. Studies evaluating the biogenesis of P-glycoprotein (P-gp) have been at the forefront of this rapidly expanding field. They have revealed a fascinating although sometimes confusing picture that has challenged our notions about general mechanisms of polytopic protein assembly and questioned specific predictions about the details and uniqueness of P-gp transmembrane topology. This review will attempt to summarize and consolidate our current knowledge of the sequence of events that gives rise to P-gp topology in the ER compartment and the implications of these events for polytopic protein biogenesis and function.
