BBS9
Description
The BBS9 (Bardet-Biedl syndrome 9) is a protein-coding gene located on chromosome 7.
BBS9, the gene encoding Bardet–Biedl syndrome 9 protein, is involved in parathyroid hormone action in bones, as its expression is downregulated by parathyroid hormone in osteoblastic cells. Mutations in this gene are associated with Bardet–Biedl syndrome.
The BBSome complex, which BBS9 is a part of, acts as a coat complex responsible for sorting specific membrane proteins to the primary cilia. This complex is crucial for ciliogenesis but not for centriolar satellite function. The BBSome interacts with the Rab8 GDP/GTP exchange factor at the basal body, facilitating the entry of Rab8(GTP) into the primary cilium. This, in turn, promotes the extension of the ciliary membrane. The BBSome binds to RAB3IP/Rabin8, the guanosyl exchange factor (GEF) for Rab8, and then Rab8-GTP localizes to the cilium, promoting the docking and fusion of carrier vesicles at the base of the ciliary membrane. BBS9 is required for the correct assembly and ciliary localization of the BBSome complex.
BBS9 is also known as B1, C18, D1, PTHB1.
