TITLE:
Cell membranes composition is defined in ER and their restitution proceed by en bloc fusion of ER generated transport vesicles
AUTHORS:
Amalia Slomiany, Bronislaw L. Slomiany
KEYWORDS:
Membrane Biogenesis; Repair Fidelity; Vesicular Transport; En Bloc Fusion
JOURNAL NAME:
Health,
Vol.2 No.12,
December
31,
2010
ABSTRACT: The synthesis of endoplasmic reticulum (ER)-derived transport vesicles is dictated by the contents and derivation of the cellular cytosol. The ER transport vesicles synthesized in the presence of gastric epithelial cells cytosol are destined for en bloc fusion with apical epithelial membrane, whereas those generated in hepa-tocytes-derived cytosol are destined for en bloc fusion with basolateral membrane. Moreover, during assembly of the dominant fraction of the apical or basolateral transport vesicles, a sub-stantial fraction of the vesicles is produced that fuses with endosomes, and the vesicles with still unknown destination that remain in cytosol. The process of ER vesicles synthesis is blocked by RNase treatment, whereas Golgi vesicles as-sembly is not affected. The experiments indicate that transport vesicles’ membrane composition and fidelity of its construction is defined in ER. The process involves synchronous membrane lipid synthesis, cotranslational intercalation of integral membrane proteins and containment of the vesicular cargo.