Arabidopsis AtNek2 Kinase is Essential and Associates with Microtubules

NIMA-related kinases (Neks) are a large family of serine/threonine kinases that have been linked to cell-cycle regulation in fungi and mammals. Large families of NIMA-related kinases are also conserved in plants. We demonstrate that AtNek2, a member of the NIMA-related kinase family in Arabidopsis, is a gene fundamental for plant survival and its down-regulation has a pleiotropic effect on leaf cell morphogenesis and plant development. Intracellular localization of YFP::AtNek2 showed that AtNek2 proteins co-distribute with the microtubular cytoskeleton. As a microtubular-associated protein AtNek2 might influence the dynamics of microtubules and consequently cell morphogenesis. This is supported by the observation that misexpression of AtNek2 in RNAi mutants leads to a distorted organization of cells.