title: Cholesterol-independent targeting of Golgi membrane proteins in insect cells.
abstract: Distinct lipid compositions of intracellular organelles could provide a physical basis for targeting of membrane proteins, particularly where transmembrane domains have been shown to play a role. We tested the possibility that cholesterol is required for targeting of membrane proteins to the Golgi complex. We used insect cells for our studies because they are cholesterol auxotrophs and can be depleted of cholesterol by growth in delipidated serum. We found that two well-characterized mammalian Golgi proteins were targeted to the Golgi region of Aedes albopictus cells, both in the presence and absence of cellular cholesterol. Our results imply that a cholesterol gradient through the secretory pathway is not required for membrane protein targeting to the Golgi complex, at least in insect cells.
authors.affiliation: Department of Cell Biology and Anatomy, Johns Hopkins Medical School, Baltimore, Maryland 21205, USA.
authors.forename: M M
authors.initials: MM
authors.lastname: Rolls
authors.forename: M T
authors.initials: MT
authors.lastname: Marquardt
authors.forename: M
authors.initials: M
authors.lastname: Kielian
authors.forename: C E
authors.initials: CE
authors.lastname: Machamer
mesh_terms: D000330:Aedes / Q000737:chemistry*; D000818:Animals; D001692:Biological Transport; D002417:Cattle; D002460:Cell Line; D002784:Cholesterol / Q000502:physiology*; D006056:Golgi Apparatus / Q000737:chemistry*; D008361:Mannosidases / Q000032:analysis / Q000378:metabolism; D008565:Membrane Proteins / Q000032:analysis* / Q000378:metabolism; D051379:Mice; D009237:N-Acetyllactosamine Synthase / Q000032:analysis / Q000378:metabolism; D011993:Recombinant Fusion Proteins; D043323:alpha-Mannosidase
chemical_list: D008565:Membrane Proteins; D011993:Recombinant Fusion Proteins; D002784:Cholesterol; D009237:N-Acetyllactosamine Synthase; D008361:Mannosidases; D043323:alpha-Mannosidase