Oleosins and Endoplasmic Reticulum in Seeds and Anthers

摘要: Three types of related subcellular oil-rich particles are present in plants: storage oil bodies inseeds for gluconeogenesis during germination, pollen providing acyl moieties membranesynthesis the tube, and tapetosomes anther tapetum delivering lipids proteins tothe maturing surface. Each these has a basic structure an body,which consists triacylglycerol matrix enclosed by layer phospholipids structuralprotein oleosins. All components body synthesized assembled endoplasmic reticulum(ER), from which budding is released. An oleosin molecule highly conserved centraldomain 72 uninterrupted hydrophobic residues flanked variable amphipathic N-and C-terminal segments. Its unique central domain presumed to haveevolved transmembrane segment ER protein. does not have N-terminal ER-targeting signal targeted recognition particleand then via its domain. Targeting studies molecules that been modifiedby adding signal, shortening centralhydrophobic stretch eliminating N- or C-terminalamphipathic stretch, provided model delineating mechanism targeting andoil bodies. A tapetosome possesses numerous oleosin-coated associated ionically with abundantmembranous vesicles, both detached ER.