Fat storage-inducing transmembrane protein (IPR019388)

Short name: FIT

Overlapping homologous superfamilies


Family relationships



This entry represents the fat storage-inducing transmembrane (FIT) family of proteins, which play an important role in lipid droplet accumulation. They are endoplasmic reticulum resident membrane proteins that induce lipid droplet accumulation in cell culture and when expressed in mouse liver [PMID: 18160536]; they mediate the partitioning of triglyceride from the ER into cytosolic fatty droplets by an as-yet undetermined mechanism. The ability to store fat in the form of cytoplasmic triglyceride droplets is conserved from Saccharomyces cerevisiae to humans [PMID: 18160536]. The FIT family of proteins are not involved in triglyceride biosynthesis [PMID: 20520733].

FIT1 and FIT2 proteins are six-transmembrane-domain containing proteins with both the N and C termini residing in the cytosol. FIT2 is the more anciently conserved homologue of the FIT family; this family of proteins do not share sequence similarity to known proteins or domains.

GO terms

Biological Process

GO:0019915 lipid storage

Molecular Function

No terms assigned in this category.

Cellular Component

GO:0005789 endoplasmic reticulum membrane

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.