The omegasome is a cell organelle consisting of lipid bilayer membranes enriched for phosphatidylinositol 3-phosphate (abbreviated PI(3)P or PtdIns3P), and related to a process of autophagy.
[1] It is a subdomain of the endoplasmic reticulum (ER),[2] and has a morphology resembling the Greek capital letter Omega (Ω).
[4] Autophagy (from Greek words for "self" and "eating") is a process of digesting or degrading cytoplasmic molecules (proteins, lipids, sugars and organelles).
[9] The phagophore expands to accommodate the items, until the omegasome is closed to produce the roughly spherical autophagosome.
[13] Omegasomes display significant functional roles in different biochemical pathways which assist in various autophagosome processes.