TY - JOUR T1 - Evidence of Presence and Activation of the two Cell Cycle Kinases Nek6 and Nek7 in the ciliated Neuroretina JF - bioRxiv DO - 10.1101/2020.03.27.012724 SP - 2020.03.27.012724 AU - Kerstin M Janisch AU - J Mie Kasanuki AU - Richard J Davis AU - Stephen H Tsang Y1 - 2020/01/01 UR - http://biorxiv.org/content/early/2020/03/29/2020.03.27.012724.abstract N2 - The serine/threonine NIMA kinases are widely found in eukaryotes. They are cell-cycle kinases that are associated with centrosomes and spindle apparatus and cilia. In cilia, NIMA kinases are reported to play a role in cilia length maintenance and deflagelation. Here we focus on the two Nek homologs, Nek6 and Nek7, and their potential role in retina. We report for the first-time expression of nek6 and nek7 mRNA and protein in retinal tissue. In particular, we detect localisation of these kinases to photoreceptors outer segments. Moreover, we are able to show a light-dependent phosphorylation of the activation loop (serine 206) of Nek6/7 in rod outer segments, suggesting activation of these kinases is downstream of the phototransduction pathway. Indeed, we demonstrate that Nek6/7 phosphorylation in the retina is dependent on Grk1 function. Furthermore, Nek6/7 phosphorylation can be stimulated in the brain by opiate drugs, suggesting that activation of Nek6/7 lies downstream of G protein coupled receptors activation, in general. Nek6/7 may couple photoreception with outer segment biogenesis through phosphorylation of downstream substrates, which may affect the microtubules of the axoneme.NIMAnever in mitose ANEKNIMA-related kinaseGPCRG-protein coupled receptorGRKG-protein coupled receptor kinaseOPLouter plexiform layerIPLinner plexiform layerOSouter segmentISinner segmentMTmicrotubules ER -