Possesses an intrinsic kinase activity (PubMed:24807905). Displays 3′-5′ exonuclease activity with a preference for single-stranded DNA (PubMed:16313181). Does not seem to have nucleoside diphosphate kinase activity (PubMed:16313181, PubMed:24807905). Microtubule inner protein (MIP) part of the dynein-decorated doublet microtubules (DMTs) in cilia axoneme, which is required for motile cilia beating (PubMed:36191189). Functional component of the gamma-tubulin ring complex, implicated in the regulation of the microtubule-nucleating activity of the gamma-tubulin ring complex in centrosomes, in a kinase activity-dependent manner (PubMed:24807905).