BBSOME complexes are considered to be the mantle complexes required for sorting specific membrane proteins into primary cilia. The BBSOME complex is required for ciliary development, but is assignable for central satellite function. This ciliary generation function is partially mediated by RAB8 GDP/GTP exchange factor, which is located in the basal body and contacts BBSOME. Rab8 (GTP) enters the primary cilia and promotes the extension of the ciliary membrane. Firstly, BBSOME binds to the ciliary membrane and binds to Rab3ip/Rabin8, the bird amino exchange factor (GEF) of Rab8. Then Rab8 GTP is localized to the cilia and promotes the docking and fusion of carrier vesicles to the base of the ciliary membrane. The BBSOME complex, together with LTZL1, controls SMO ciliary transport and contributes to the Sonic Hedgehog (SHH) pathway. BBSOME composite ciliary localization is necessary, but does not require appropriate composite components.
