The nuclear envelope is a membrane system which surrounds the nucleoplasm of eukaryotic cells. It is composed of the nuclear lamina, nuclear pore complexes and two nuclear membranes. The space between the two membranes is called the nuclear intermembrane space.
The inner membrane of the nucleus is the membrane which separates the nuclear matrix from the intermembrane space. In mammals, the inner nuclear membrane is associated with heterochromatin and the nuclear lamina.
The membrane surrounding the nucleus. This term is used when it is not known if the protein is found in or associated with the inner or outer nuclear membrane.
Catalyzes triacylglycerol (TAG) formation by an acyl-CoA independent pathway. The enzyme specifically transfers acyl groups from the sn-2 position of a phospholipid to diacylglycerol (DAG), thus forming an sn-1-lysophospholipid (PubMed:10747858, PubMed:10829075, PubMed:32349126). The preferred acyl donors are phosphatidylethanolamine (PE) and phosphatidylcholine (PC). Also capable of using broad acyl donors such as phosphatidic acid (PA), phosphatidylserine (PS), phosphatidylglycerol (PG) and phosphatidylinositol (PI), as well as monogalactosyldiacylglycerol (MGDG), digalactosyldiacylglycerol (DGDG), and acyl-CoA, and it is more likely to use unsaturated acyl donors. As acyl acceptors, it prefers 1,2- over 1,3-diacylglycerol (DAG). Additionally, has esterification activity that can utilize methanol as acyl acceptor to generate fatty acid methyl esters (FAME) (PubMed:30706417). Can also utilize ceramide instead of DAG, acylating the ceramides by attaching a fatty acid to the hydroxy group on the first carbon atom of the long-chain base to produce 1-O-acylceramides (PubMed:22738231). Involved in lipid particle synthesis from the endoplasmic reticulum, promoting localized TAG production at discrete ER subdomains (PubMed:32349126). Relocates from the endoplasmic reticulum to a subdomain of the inner nuclear membrane upon nutrient starvation, where it provides a site of TAG synthesis, which is coupled with nuclear membrane remodeling (PubMed:31422915). {Experimental EvidencePubMed:10747858, Experimental EvidencePubMed:10829075, Experimental EvidencePubMed:22738231, Experimental EvidencePubMed:30706417, Experimental EvidencePubMed:31422915, Experimental EvidencePubMed:32349126}.
National and Kapodistrian University of Athens
Department of Biology
Biophysics & Bioinformatics Laboratory