BBS2

This gene is a member of the Bardet-Biedl syndrome (BBS) gene family. Bardet-Biedl syndrome is an autosomal recessive disorder characterized by severe pigmentary retinopathy, obesity, polydactyly, renal malformation and cognitive disability. The proteins encoded by BBS gene family members are structurally diverse and the similar phenotypes exhibited by mutations in BBS gene family members is likely due to their shared roles in cilia formation and function. Many BBS proteins localize to the basal bodies, ciliary axonemes, and pericentriolar regions of cells. BBS proteins may also be involved in intracellular trafficking via microtubule-related transport. The protein encoded by this gene forms a multiprotein BBSome complex with seven other BBS proteins.[provided by RefSeq, Oct 2014]

Full Name

Bardet-Biedl Syndrome 2

Function

The BBSome complex is thought to function as a coat complex required for sorting of specific membrane proteins to the primary cilia. The BBSome complex is required for ciliogenesis but is dispensable for centriolar satellite function. This ciliogenic function is mediated in part by the Rab8 GDP/GTP exchange factor, which localizes to the basal body and contacts the BBSome. Rab8(GTP) enters the primary cilium and promotes extension of the ciliary membrane. Firstly the BBSome associates with the ciliary membrane and binds to RAB3IP/Rabin8, the guanosyl exchange factor (GEF) for Rab8 and then the Rab8-GTP localizes to the cilium and promotes docking and fusion of carrier vesicles to the base of the ciliary membrane. The BBSome complex, together with the LTZL1, controls SMO ciliary trafficking and contributes to the sonic hedgehog (SHH) pathway regulation. Required for proper BBSome complex assembly and its ciliary localization.

Biological Process

Adult behavior Source: BHF-UCL
Artery smooth muscle contraction Source: Ensembl
Brain morphogenesis Source: BHF-UCL
Cartilage development Source: Ensembl
Cerebral cortex development Source: BHF-UCL
Cilium assembly Source: BHF-UCL
Fat cell differentiation Source: BHF-UCL
Golgi to plasma membrane protein transport Source: MGI
Hippocampus development Source: BHF-UCL
Melanosome transport Source: BHF-UCL
Negative regulation of appetite by leptin-mediated signaling pathway Source: BHF-UCL
Negative regulation of gene expression Source: Ensembl
Negative regulation of multicellular organism growth Source: BHF-UCL
Non-motile cilium assembly Source: Ensembl
Photoreceptor cell maintenance Source: BHF-UCL
Positive regulation of multicellular organism growth Source: Ensembl
Protein localization Source: BHF-UCL
Protein localization to organelle Source: BHF-UCL
Regulation of cilium beat frequency involved in ciliary motility Source: BHF-UCL
Sperm axoneme assembly Source: BHF-UCL
Striatum development Source: BHF-UCL
Vasodilation Source: Ensembl
Visual perception Source: UniProtKB

Cellular Location

Cytoplasm; Cilium membrane; Centriolar satellite

Involvement in disease

Bardet-Biedl syndrome 2 (BBS2): A syndrome characterized by usually severe pigmentary retinopathy, early-onset obesity, polydactyly, hypogenitalism, renal malformation and mental retardation. Secondary features include diabetes mellitus, hypertension and congenital heart disease. Bardet-Biedl syndrome inheritance is autosomal recessive, but three mutated alleles (two at one locus, and a third at a second locus) may be required for clinical manifestation of some forms of the disease.
Retinitis pigmentosa 74 (RP74): A retinal dystrophy belonging to the group of pigmentary retinopathies. Retinitis pigmentosa is characterized by retinal pigment deposits visible on fundus examination and primary loss of rod photoreceptor cells followed by secondary loss of cone photoreceptors. Patients typically have night vision blindness and loss of midperipheral visual field. As their condition progresses, they lose their far peripheral visual field and eventually central vision as well.