This entry represents transmembrane proteins which belong to the Fat storage-inducing transmembrane protein family (FIT/FITM, also known as Acyl-coenzyme A diphosphatase) [1-6]. The members are conserved from yeasts to humans and are localised to the endoplasmic reticulum where they are involved in triglyceride lipid droplet formation [2,5], important for maintaining ER structure and for lipid droplets (LDs) biogenesis, involved in maintaining lipid and energy homeostasis [3,5,6]. In mammals there are two FIT proteins, FIT1, which is muscle specific and FIT2, which is expressed in most other tissues [4,6]. Yeast has two FIT2 orthologues, called Scs3p and Yft2.

1: Cloning and sequence of the SCS3 gene which is required for inositol prototrophy in Saccharomyces cerevisiae. Hosaka K, Nikawa J, Kodaki T, Ishizu H, Yamashita S; J Biochem. 1994;116:1317-1321. PMID:7706223

2: Structural insights into triglyceride storage mediated by fat storage-inducing transmembrane (FIT) protein 2. Gross DA, Snapp EL, Silver DL; PLoS One. 2010;5:e10796. PMID:20520733

3: Evolutionarily conserved gene family important for fat storage. Kadereit B, Kumar P, Wang WJ, Miranda D, Snapp EL, Severina N, Torregroza I, Evans T, Silver DL; Proc Natl Acad Sci U S A. 2008;105:94-99. PMID:18160536

4: FIT2 is an acyl-coenzyme A diphosphatase crucial for endoplasmic reticulum homeostasis. Becuwe M, Bond LM, Pinto AFM, Boland S, Mejhert N, Elliott SD, Cicconet M, Graham MM, Liu XN, Ilkayeva O, Saghatelian A, Walther TC, Farese RV Jr.; J Cell Biol. 2020; [Epub ahead of print] PMID:32915949

5: A conserved family of proteins facilitates nascent lipid droplet budding from the ER. Choudhary V, Ojha N, Golden A, Prinz WA; J Cell Biol. 2015;211:261-271. PMID:26504167

6: Architecture of Lipid Droplets in Endoplasmic Reticulum Is Determined by Phospholipid Intrinsic Curvature. Choudhary V, Golani G, Joshi AS, Cottier S, Schneiter R, Prinz WA, Kozlov MM; Curr Biol. 2018;28:915-926. PMID:29526591