Primary cilia and cilia proteins are ubiquitous on the cell surface of vertebrates, and are based on microtubules, which assist in signal transduction between the cell surface and the surrounding environment[1,2], which in turn affects cell proliferation, differentiation and gene expression[3]。 Because proteins cannot be synthesized inside cilias, its structural and functional integrity cannot be separated from the intraciliar transport system, which is composed of intraflagellar transport (IFT) complexes A and B, and can move in both directions along the ciliar axis. At present, 22 IFT proteins are known to be involved in the formation of IFT complexes A and B[4,5]Where 14 proteins are involved in IFT-B complex formation, including IFT22, IFT25, IFT27, IFT46, IFT52, IFT56, IFT70, IFT74, IFT81, IFT88, IFT20, IFT38, IFT54, IFT57, IFT80, and IFT172[6]。 The mutation of these proteins usually leads to structural and functional defects of the cilia, and induces a series of ciliopathies, which can involve a variety of tissues and organs, and the more obvious manifestation is skeletal development abnormalities[7]。 IFT80 is one of the core proteins of IFT-B complex, which mediates material transport from the base of cilia to the tip of cilia, and is crucial for the formation of cilia. The N-terminus of IFT80 protein has two β-helix structures followed by an α-helix extension, the first β-helix at the N-terminus is connected to the IFT-B complex via IFT38, while the second β-helix and the α-helix extension at the C-terminus are involved in IFT80 homodimerization, and the IFT80 homodimerization structure is an essential structure for cilia formation[8]。 A large number of studies have shown that IFT80 protein is crucial for skeletal development and is expected to be the target of tissue repair and regeneration.
