Protein kinase that is involved in mitotic regulation. Integral component of the mitotic spindle-assembly checkpoint which is necessary for proper chromosome segregation during metaphase-anaphase transition. Required for association of MAD2L1 to kinetochore. Phosphorylates SGOL1. May have a role at the G2-M transition. May also play a role in meiosis. Isoform 1 but not isoform 2 appears to play a role in centrosome splitting. Isoform 1 phosphorylates and activates NEK11 in G1/S-arrested cells. Isoform 2, which is not present in the nucleolus, does not.
Isoform 1 and isoform 2 are expressed in peripheral blood T-cells and a wide variety of transformed cell types.
Belongs to the protein kinase superfamily. NEK Ser/Thr protein kinase family. NIMA subfamily. Contains 1 protein kinase domain.
Accumulates throughout S phase and shows maximal levels in late G2. This expression pattern is highly reminiscent of that of A and B cyclins. Isoform 1 and isoform 2 expression is low in the G1 phase and increases in the S/G2 phases. Isoform 1 is absent from cells arrested in the G2/M prometaphase. Isoform 2 remains present in cells arrested in the G2/M prometaphase.
It is unsure whether Thr-170 or Ser-171 is phosphorylated.
Cytoplasm. Predominantly cytoplasmic; Nucleus > nucleolus. Has a nucleolar targeting/ retention activity via a coiled-coil domain at the C-terminal end and Nucleus. Chromosome > centromere. Chromosome > centromere > kinetochore. Co-localizes with SGOL1 and MAD1L1 at the kinetochore. Not associated with kinetochore in the interphase but becomes associated with it upon the breakdown of the nuclear envelope.