TTC8

TTC8 (BBS8) is a tetratricopeptide-repeat (TPR) superhelical protein and one of the eight core subunits of the BBSome, a coat-like octameric adaptor complex (BBS1, BBS2, BBS4, BBS5, BBS7, BBS8/TTC8, BBS9 and BBIP1/BBIP10). The BBSome traffics specific membrane and signaling proteins (including G-protein-coupled receptors such as Smoothened) into and out of the primary cilium, working with intraflagellar transport (IFT) and the small GTPase ARL6/BBS3, and cooperating with the Rab8 guanine-nucleotide exchange factor Rabin8 (RAB3IP) to promote ciliary membrane biogenesis. TTC8 localizes to the centrosome, ciliary basal body, centriolar satellites and the ciliary membrane, and is required for ciliogenesis. It is widely expressed and has tissue-specific isoforms, including a retina-specific exon important in photoreceptors. Loss of TTC8 function causes Bardet-Biedl syndrome type 8 (BBS8) and nonsyndromic retinitis pigmentosa (RP51).

Disorders

Relationship is the entry's genetic[].relationship_type. untyped means the entry has a genetic record for the gene but does not type it; its free-text association is shown instead.

An entry matches when ClinGen's MONDO disease is the entry's own disease term, a subtype term, or an exact-match mapping. An amber status marks an entry ClinGen supports the gene for (Definitive, Strong or Moderate) whose own record does not type it. A Limited, Disputed or Refuted tier on such an entry is not a gap.

• bbsome_trafficking via Bardet-Biedl syndrome, BBSome-related retinitis pigmentosa