The BBSome is an octameric protein complex. It is a component of the

basal body A basal body (synonymous with basal granule, kinetosome, and in older cytological literature with blepharoplast) is a protein structure found at the base of a eukaryotic undulipodium (cilium or flagellum). The basal body was named by Theodor W ...

and is involved in trafficking cargos to the

primary cilium The cilium, plural cilia (), is a membrane-bound organelle found on most types of eukaryotic cell, and certain microorganisms known as ciliates. Cilia are absent in bacteria and archaea. The cilium has the shape of a slender threadlike projecti ...

. The BBSome is a complex of seven

Bardet–Biedl syndrome Bardet–Biedl syndrome (BBS) is a ciliopathic human genetic disorder that produces many effects and affects many body systems. It is characterized by rod/cone dystrophy, polydactyly, central obesity, hypogonadism, and kidney dysfunction in som ...

(BBS) proteins:

BBS1 Bardet–Biedl syndrome 1 protein is a protein that in humans is encoded by the ''BBS1'' gene. BBS1 is part of the BBSome complex, which required for ciliogenesis. Mutations in this gene have been observed in patients with the major form (type 1) ...

BBS2 Bardet–Biedl syndrome 2 protein is a protein that in humans is encoded by the ''BBS2'' gene In biology, the word gene (from , ; "...Wilhelm Johannsen coined the word gene to describe the Mendelian units of heredity..." meaning ''generat ...

BBS4 Bardet–Biedl syndrome 4 is a protein that in humans is encoded by the ''BBS4'' gene. This gene encodes a protein which contains tetratricopeptide repeats (TPR), similar to O-linked N-acetylglucosamine transferase. Mutations in this gene have be ...

BBS5 Bardet–Biedl syndrome 5 protein is a protein that in humans is encoded by the ''BBS5'' gene. This gene encodes a protein that has been directly linked to Bardet–Biedl syndrome. The primary features of this syndrome include retinal dystrophy, ...

BBS7 Bardet–Biedl syndrome 7 is a protein that in humans is encoded by the ''BBS7'' gene. Mutations in this gene are associated with the Bardet–Biedl syndrome Bardet–Biedl syndrome (BBS) is a ciliopathic human genetic disorder that produce ...

BBS8 Tetratricopeptide repeat domain 8 (TTC8) also known as Bardet–Biedl syndrome 8 is a protein that in humans is encoded by the ''TTC8'' gene. Function TTC8 is associated with gamma-tubulin, BBS4, and PCM1 in the centrosome. PCM1 in turn is in ...

and

BBS9 Bardet–Biedl syndrome 9 is a protein that in humans is encoded by the ''BBS9'' gene. The expression of the Bardet–Biedl syndrome 9 protein is downregulated by parathyroid hormone in osteoblastic cells, and therefore, is thought to be involved ...

. In addition the BBSome contains the BBIP10 protein. Mutation in each of this eight BBSome genes (as well as other 14 BBS genes identified to date ) causes a severe multiorganic syndrome (BBS) presenting in most cases by retinal dystrophy, obesity, renal anomalies, post-axial polydactyly, and developmental delay.

History

The BBSome was first identified in 2007 by Peter K. Jackson and colleagues.

Assembly

BBSome assembly has been shown to be mediated by a complex containing a further three BBS proteins:

BBS6 McKusick–Kaufman/Bardet–Biedl syndromes putative chaperonin is a protein that in humans is encoded by the ''MKKS'' gene. This gene encodes a protein with sequence similarity to the chaperonin family. The encoded protein may have a role in pro ...

, BBS10 and BBS12. In addition chaperonins of the CCT/TRiC family are involved.

References

* Loktev, A.V., Q. Zhang, J. S. Beck, C. C. Searby, T. E. Scheetz, J. F. Bazan, D. C. Slusarski, V. C. Sheffield, P. K. Jackson, M. V. Nachury (2008). A BBSome subunit links ciliogenesis, microtubule stability, and acetylation. Developmental Cell 2008 15:854-65. Organelles {{cell-biology-stub