Required for ciliogenesis (PubMed:24797473). Phosphorylates KIF3A (By similarity). Involved in the control of ciliary length (PubMed:24853502). Regulates the ciliary localization of SHH pathway components as well as the localization of IFT components at ciliary tips (By similarity). May play a key role in the development of multiple organ systems and particularly in cardiac development (By similarity). Regulates intraflagellar transport (IFT) speed and negatively regulates cilium length in a cAMP and mTORC1 signaling-dependent manner and this regulation requires its kinase activity (By similarity). ATP + L-seryl-[protein] = ADP + H(+) + O-phospho-L-seryl-[protein] ATP + L-threonyl-[protein] = ADP + H(+) + O-phospho-L-threonyl-[protein] Also found at the ciliary tip (PubMed:24797473). Nuclear localization has been observed with a GFP-tagged construct in transfected HeLa cells (PubMed:12103360, PubMed:19185282). Predominant cytoplasmic localization has been observed with a N-terminally GFP-tagged construct. Expressed in heart, brain, placenta, pancreas, thymus, prostate, testis, ovary, small intestine and colon, with highest levels in placenta and testis. Not detected in spleen. Also expressed in many cancer cell lines. Autophosphorylated on serine and threonine residues. Phosphorylation at Thr-157 increases kinase activity. The disease is caused by variants affecting the gene represented in this entry. The disease is caused by variants affecting the gene represented in this entry. Belongs to the protein kinase superfamily. CMGC Ser/Thr protein kinase family. CDC2/CDKX subfamily. Extended N-terminus.