RELCH is a RAB11 effector protein that regulates intracellular cholesterol distribution from recycling endosomes to the trans-Golgi network through its interactions with RAB11 and OSBP [].
A number of eukaryotic proteins that seem to be involved with sterol synthesis and/or its regulation have been found []to be evolutionary related. These include mammalian oxysterol-binding protein (OSBP), a protein of about 800 amino-acid residues that binds a variety of oxysterols (oxygenated derivatives of cholesterol) [, ]; yeast Osh1, a protein of 859 residues that also plays a role in ergosterol synthesis []; yeast proteins Hes1 and Kes1, highly related proteins of 434 residues that seem to play a role in ergosterol synthesis [, ]; Probable transporter efuK from the fungi Hormonema carpetanum, which is involved in the biosynthesis of enfumafungin [[cite30051576]]; and OSBP-related proteins (ORP) from plants such as Arabidopsis thaliana [].The core structure of OSBP has a large meander β-sheet of 12 strands wrapped around the N-terminal (distorted) alpha-hairpin. It shares some similarity with transmembrane β-barrel proteins.
