Bbs4 is a gene encoding a protein involved in Bardet-Biedl syndrome (BBS), an autosomal recessive ciliopathy. BBS proteins localize to cilia and basal bodies, participating in cilia biogenesis and function [1].

In Bbs4 -/- mice, olfactory sensory neuron (OSN) cilia are shorter and fewer, with asynchronous rates of intraflagellar transport (IFT)-A/B particle movements, indicating miscoordination in IFT complex trafficking. Also, BBS4 loss leads to a reduction in basal body numbers in OSNs [2].

In adipocytes, Bbs4 silencing in 3T3F442A pre-adipocytes induces accelerated cell division and aberrant differentiation, resulting in more triglyceride accumulation [4]. BBS4 silencing in neuronal cells reduces sensitivity to endoplasmic reticulum (ER) stress during differentiation and under ER-stress induction, as it is essential for the nuclear transport of transcription factors sXBP-1 and ATF6α p50 [3].

In conclusion, Bbs4 plays crucial roles in cilia-related functions in olfactory neurons, and in the regulation of adipocyte proliferation, differentiation, and ER stress response in adipocytes and neuronal cells. The study of Bbs4 knockout mouse models has provided insights into its functions in the context of ciliopathies, obesity, and neural development-related diseases [2,3,4].