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 (PubMed:24094853). Required for cilia integrity and function in sensory neurons (PubMed:2428682, PubMed:17314406, PubMed:24094853). Maintains cilia integrity, partly by modulating the assembly and transport of intraflagellar proteins along the ciliary axoneme (PubMed:24094853). Required for normal mating behavior and normal responses to environmental and chemical stimuli (PubMed:2428682, PubMed:17314406, PubMed:24094853). Expressed in head ciliated neurons. Ciliary degeneration which is partly due to irregular localization of ciliary components (PubMed:24094853). This likely leads to the impaired intraflagellar transport of proteins along the ciliary axoneme during the later stages of larval development (PubMed:24094853). Lack of or defects in amphid cilia including no transition zone and axoneme structures in amphid wing neurons, enlargened dendritic endings, variable cilia length of ADL neurons, absent or irregularly orientated cilia of the AFD neuron and absent striated rootlets which are normally associated with cilia basal bodies and positioned at the base of cilia in IL1, OLQ and BAG neurons (PubMed:2428682, PubMed:17314406, PubMed:24094853). Behavioral defects including no obvious mating behavior, impaired dauer formation, osmotic and CO(2+) avoidance and impaired chemotaxis (PubMed:2428682, PubMed:24094853). Belongs to the rootletin family.