Loss of Kat2b impairs intraflagellar transport and the Hedgehog signaling pathway in primary cilia

Primary cilia are sensory organelles that regulate various signaling pathways. For this, microtubules work as a highway, and they are tuned with post-translational modifications, such as acetylation. However, the role of acetylation in the regulation of primary cilia remains uncertain. Here, we identified K (lysine) acetyltransferase 2B (Kat2b) as a novel regulator of primary cilia. Kat2b localizes to the cytosol, centrosome, and the cilium basal body. Also, the basal expression of Kat2b gradually increases during ciliogenesis. Kat2b regulates the rate of cilia assembly and the acetylation of α-tubulin via its catalytic activity. The loss of Kat2b reduces the recruitment of intraflagellar transport (IFT) components to the ciliary axoneme and impairs Hedgehog signaling activation. In addition, Kat2b-knockout mice show mild abnormalities and ciliary IFT defect in kidneys. Thus, our new findings establish a link between acetylation regulated by Kat2b and its relevance to ciliary assembly and function.