The Function of Chorein

Chorein is the protein encoded by gene VPS13A which is altered in chorea-acanthocytosis (ChAc). It belongs to the VPS13 protein family which, in mammals, has three other members: VPS13B, VPS13C and VPS13D. These pro- teins are similar to Vps13p, a yeast protein shown to be involved in intra-cellular trafficking of a number of transmembrane proteins. Chorein and its homologous human proteins lack domains or motifs of known function. This, together with their large size, makes the functional characterisation of these proteins a difficult task. Nevertheless, we have undertaken this task following a molecular and cellular biology approach. We have cloned the cDNA for the human VPS13 genes and used them for transfection of mammalian cell lines. We present here an overview of the