title: Cotranslational Integration of Soybean (Glycine max) Oil Body Membrane Protein Oleosin into Microsomal Membranes.
abstract: Storage triglycerides in oil seeds are sequestered in discrete organelles termed oil bodies. They are bounded by a monolayer of phospholipids in which a few distinct proteins (oleosins) are embedded. Synthesis of soybean (Glycine max) 24-kD oleosin was analyzed by in vitro transcription and translation in reticulocyte lysate in the presence of canine microsomes. Our results show that 24-kD oleosin is cotranslationally integrated into microsomal membranes. We demonstrate that oleosin is integrated into a bilayer membrane in preference to the oil body monolayer membrane, indicating that oleosin is synthesized on the endoplasmic reticulum (ER). A new model of oil body assembly involving a conformational change through initial association with the ER membrane is proposed.
authors.affiliation: Plant Molecular Biology Laboratory, U.S. Department of Agriculture, Agricultural Research Service, Beltsville, Maryland 20705.
authors.forename: D. S.
authors.initials: DS
authors.lastname: Loer
authors.forename: E. M.
authors.initials: EM
authors.lastname: Herman