Phosphorylates serines and threonines, but also appears to possess tyrosine kinase activity (PubMed:1382974). Involved in DNA damage checkpoint control and for proper DNA damage repair (PubMed:18843199). In response to injury that includes DNA damage, NEK1 phosphorylates VDAC1 to limit mitochondrial cell death (By similarity). May be implicated in the control of meiosis (PubMed:1382974). Involved in cilium assembly (By similarity). ATP + L-seryl-[protein] = ADP + H(+) + O-phospho-L-seryl-[protein] ATP + L-threonyl-[protein] = ADP + H(+) + O-phospho-L-threonyl-[protein] Binds to CBY2 (PubMed:12204287). Found in a complex with CFAP410, NEK1 and SPATA7 (By similarity). Interacts with CFAP410 (By similarity). Interacts (via Ser-997 phosphorylated form) with 14-3-3 proteins (PubMed:28235073). Associated with the pericentriolar material (By similarity). Localizes to centrosome during interphase and mitosis (PubMed:16267153). Predominantly in testes (germ cells and Sertoli cells). Lower levels in ovary (oocytes and granulosa cells), thymus and lung. In female, expressed as follicles enter the secondary stage until ovulation occurs. In the male reproductive system, the expression is limited to spermatocytes and spermatids. Belongs to the protein kinase superfamily. NEK Ser/Thr protein kinase family. NIMA subfamily.