Fig. 1. NOSTRIN belongs to the PCH family of proteins. (A) Domain structure of selected members of the human PCH protein family. The proteins share a characteristic composition comprising an N-terminal FCH domain, a C-terminal SH3 domain and a coiled-coil domain located C-terminally of the FCH domain. Some members including NOSTRIN, FBP17, CIP4 and Toca-1 also contain an HR1 motif, which harbors a coiled-coil domain and has been described as a Rho GTPase binding unit. (B) Phylogenetic tree of PCH family proteins. The phylogenetic tree was constructed by alignment of sequence data of denoted proteins (ClustalW), applying the Phylodraw0.8 software. According to this, pacsins represent the closest relatives of NOSTRIN.