function:Major structural component of the ciliary rootlet, a cytoskeletal-like structure in ciliated cells which originates from the basal body at the proximal end of a cilium and extends proximally toward the cell nucleus. Contributes to centrosome cohesion before mitosis.,PTM:Phosphorylated by NEK2 which may regulate its association with centrosomes. Phosphorylated upon DNA damage, probably by ATM or ATR.,similarity:Belongs to the rootletin family.,subcellular location:In ciliated cells, associated with ciliary rootlets. In non-ciliated cells, localized between, around and at the proximal ends of the centrioles. Dissociates from the centrioles at the onset of mitosis and reassociates with them at anaphase.,subunit:Homopolymer. Interacts with KLC3, NEK2 and the N-terminus of CEP250.,