Bbs1-flox Mouse

Bbs1, short for Bardet-Biedl syndrome 1 gene, encodes a protein that is part of the BBSome complex. The BBSome is involved in the trafficking of ciliary membrane proteins, such as G protein-coupled receptors (GPCRs), by connecting the intraflagellar transport (IFT) machinery to cargo GPCRs. This process is crucial for cilia function, and cilia play important roles in tissue development and signal transduction [2,3].

Mutations in Bbs1 can lead to Bardet-Biedl syndrome (BBS), a rare autosomal recessive ciliopathy. BBS is characterized by features like retinal dystrophy, obesity, post-axial polydactyly, renal dysfunction, learning difficulties, and hypogonadism [2]. In Bbs1-knockout (KO) cells, there are defects in the ciliary entry of other BBSome subunits and ARL6, as well as in ciliary retrograde trafficking and the export of GPCRs, Smoothened and GPR161 [3]. In humans, a severe branchpoint variant in Bbs1, along with a mild missense variant, can underlie non-syndromic retinitis pigmentosa, with the branchpoint variant causing a complex splicing defect [1].

In conclusion, Bbs1 is essential for the proper assembly and function of the BBSome complex, which is crucial for ciliary protein trafficking. Research on Bbs1, especially through gene knockout models, has revealed its significant role in ciliopathies like Bardet-Biedl syndrome and non-syndromic retinitis pigmentosa, helping us better understand the molecular mechanisms of these diseases.