title: Getting membrane proteins on and off the shuttle bus between the endoplasmic reticulum and the Golgi complex.
abstract: Secretory proteins exit the endoplasmic reticulum (ER) in coat protein complex II (COPII)-coated vesicles and then progress through the Golgi complex before delivery to their final destination. Soluble cargo can be recruited to ER exit sites by signal-mediated processes (cargo capture) or by bulk flow. For membrane proteins, a third mechanism, based on the interaction of their transmembrane domain (TMD) with lipid microdomains, must also be considered. In this Commentary, I review evidence in favor of the idea that partitioning of TMDs into bilayer domains that are endowed with distinct physico-chemical properties plays a pivotal role in the transport of membrane proteins within the early secretory pathway. The combination of such self-organizational phenomena with canonical intermolecular interactions is most likely to control the release of membrane proteins from the ER into the secretory pathway.
authors.affiliation: CNR Institute of Neuroscience, Milan 20129, Italy n.borgese@in.cnr.it.
authors.forename: Nica
authors.identifier: http://orcid.org/0000-0002-7537-3974
authors.initials: N
authors.lastname: Borgese
mesh_terms: D000818:Animals; D022181:COP-Coated Vesicles / Q000378:metabolism; D004721:Endoplasmic Reticulum / Q000378:metabolism*; D006056:Golgi Apparatus / Q000378:metabolism*; D006801:Humans; D021962:Membrane Microdomains / Q000378:metabolism*; D008565:Membrane Proteins / Q000378:metabolism*; D046912:Multiprotein Complexes / Q000378:metabolism*; D021381:Protein Transport; D055571:Secretory Pathway
chemical_list: D008565:Membrane Proteins; D046912:Multiprotein Complexes
keywords: Anterograde transport; Cargo capture; Membrane proteins; Partitioning; Retrograde transport; Sorting signals