Post-translational modification enzymes as key regulators of ciliary protein trafficking

Primary cilia are evolutionarily conserved microtubule-based organelles that protrude from the surface of almost all cell types and decode a variety of extracellular stimuli. Ciliary dysfunction causes human diseases named ciliopathies, which span a wide range of symptoms, such as developmental and sensory abnormalities. The assembly, disassembly, maintenance and function of cilia rely on protein transport systems including intrafiagellar transport (IFT) and lipidated protein intrafiagellar targeting (LIFT). IFT is coordinated by three multisubunit protein complexes with molecular motors along the ciliary axoneme, while LIFT is mediated by specific chaperones that directly recognize lipid chains. Recently, it has become clear that several post-translational modification enzymes play crucial roles in the regulation of IFT and LIFT. Here, we review our current understanding of the roles of these post-translational modification enzymes in the regulation of ciliary protein trafficking as well as their regulatory mechanisms, physiological significance and involvement in human diseases. [GRAPHICS] .

Automated summary

Primary cilia, evolutionarily conserved microtubule-based organelles protruding from most cell types, play crucial roles in decoding extracellular stimuli. Ciliary dysfunction can lead to ciliopathies, a range of human diseases with symptoms like developmental and sensory abnormalities. Protein transport systems like IFT and LIFT are essential for cilia assembly, maintenance, and function, with post-translational modification enzymes playing key roles in regulation.