Post-Translational Modifications in Cilia and Ciliopathies

Cilia are microtubule-based organelles that extend from the surface of most vertebrate cells, and they play important roles in diverse cellular processes during embryonic development and tissue homeostasis. Mutations in ciliary proteins are associated with a wide range of human diseases, collectively referred to as ciliopathies. The past decades have witnessed significant advances in the identification of post-translational modifications (PTMs) in ciliary proteins, as well as the enzymes responsible for the PTMs. For example, acetylation of α-tubulin at lysine 40 is essential for ciliary assembly and maintenance, while ubiquitination of centrosomal proteins, such as pericentriolar material 1, regulates ciliary disassembly. In addition, accumulating evidence has shown that PTMs are essential for modulating ciliary structure and function, and that dysregulation of these modifications leads to the development of ciliopathies. In this review, current knowledge of PTMs in ciliary proteins is summarized, and their roles in regulating ciliary formation, homeostasis, and signaling are highlighted. The contribution of aberrant ciliary PTMs to ciliopathies is also discussed, along with the potential of targeting PTMs for ciliopathy treatment, including pharmacological modulation of PTM-related enzymes or substrates, which may provide new avenues for therapeutic intervention in ciliopathies.