Incorporation of cytochrome b5 into endoplasmic reticulum vesicles as protein-lysophospholipid micelles

Cytochrome b5 is incorporated into vesicles of the endoplasmic reticulum as protein-lysophosphatidylcholine micelles. Cytochrome b5 becomes firmly bound to the membrane and at the same time lysophosphatidylcholine is acylated by acyltransferases of the endoplasmic reticulum and converted into the membrane component phosphatidylcholine. The possibility of an insertion of cytochrome b5 into the endoplasmic reticulum in vivo by this mechanism is discussed.