FITM2
Description
The FITM2 (fat storage inducing transmembrane protein 2) is a protein-coding gene located on chromosome 20.
FITM2 is a human gene located at 20q13.12 that encodes a protein involved in fat storage. The protein is a member of the FIT protein family, which is conserved throughout evolution and plays a role in storing fat as cytoplasmic triglyceride droplets. FIT proteins facilitate the segregation of triglycerides into cytosolic lipid droplets but are not involved in triglyceride biosynthesis. In mammals, both FIT2 and FIT1 are embedded in the ER membrane where they regulate lipid droplet formation. In S. cerevisiae, FITM2 also contributes to phospholipid metabolism. These triglycerides are encapsulated by a phospholipid monolayer within various structures called lipid particles, oil bodies, adiposomes, eicosasomes, and most commonly, lipid droplets.
FITM2 is an enzyme that hydrolyzes fatty acyl-CoA to produce acyl-4'-phosphopantetheine and adenosine 3',5'-bisphosphate. It preferentially hydrolyzes unsaturated long-chain acyl-CoA substrates like oleoyl-CoA and arachidonoyl-CoA within the endoplasmic reticulum (ER) lumen. This activity is crucial for maintaining ER structure and facilitating the formation of lipid droplets (LDs), which are lipid storage organelles involved in lipid and energy homeostasis. FITM2 directly binds to diacylglycerol (DAGs) and triacylglycerol, contributing to LD biogenesis. It may also promote the directional budding of nascent LDs from the ER into the cytosol by reducing DAG levels at sites of LD formation. Additionally, FITM2 plays a role in regulating cell morphology and cytoskeletal organization.
FITM2 is also known as C20orf142, Fit2, SIDDIS, dJ881L22.2.
