Involved in both the selection of Gomisin-D ciliary proteins, which likely contain specific motifs and the transport along the axonemal microtubule doublets. The components of these machineries can either be specifically devoted to ciliary-protein transport and/or ciliogenesis, as IFT proteins, or participate in other cellular processes, as reported for the aPKC-par3-par6 polarity cassette, the 14-3-3 adaptor protein and Kif3A, a kinesin required for the anterograde transport towards the tip of the PC. Polycystins, proteins involved in mechano-sensation of tubular renal cells and growth factor receptors figure among the proteins that are highly enriched in ciliary membranes. Receptors belonging to the G-protein coupled receptor family are involved in the sensing of many different kinds of molecules including odorants, ions, amines, proteins or light, and thus regulate a large array of physiological processes. Some GPCRs accumulate at the PC, such as the somatostatin type 3 receptor, which is localized at PCs in neurons, or smoothened, the GPCR-like transmembrane protein controlling the Hedgehog pathway, for which translocation to the PC is essential for signalling activity. Most GPCRs are regulated by non visual arrestins, arrestin2 and arrestin3, also known as b-arrestin1 and b-arrestin2, which uncouple activated receptors from Gproteins, promote their endocytosis through clathrin-coated pits and mediate receptor-dependent activation of MAP kinases. barrs regulate numerous key physiological and developmental processes as shown by the fact that the lack of both Pimozide isoforms results in early embryonic lethality. They are highly conserved among higher eukaryotes, although only vertebrates express the two isoforms, which show a high sequence homology and are encoded by two separate genes. barr isoforms share most of their partners and functions, however, several isoform-specific roles have also been described. In particular, only barr2 displays 
an active nucleocytoplasmic shuttling, which redistributes nuclear binding partners to the cytoplasm, whereas regulation of histone acetylation at certain promoters was only reported for barr1. Interestingly, barr2, not barr1, was found in the cilia of olfactory neurons, suggesting that the former might regulate odorant receptors within these structures, which are very similar to PCs. Here, we report that barr2 is specifically localized to the centrosome of cycling cells.