title: Binding of Kif23-iso1/CHO1 to 14-3-3 is regulated by sequential phosphorylations at two LATS kinase consensus sites.
abstract: Kif23 kinesin is an essential actor of cytokinesis in animals. It exists as two major isoforms, known as MKLP1 and CHO1, the longest of which, CHO1, contains two HXRXXS/T NDR/LATS kinase consensus sites. We demonstrate that these two sites are readily phosphorylated by NDR and LATS kinases in vitro, and this requires the presence of an upstream -5 histidine residue. We further show that these sites are phosphorylated in vivo and provide evidence revealing that LATS1,2 participate in the phosphorylation of the most C-terminal S814 site, present on both isoforms. This S814 phosphosite was previously reported to constitute a 14-3-3 binding site, which plays a role in Kif23 clustering during cytokinesis. Surprisingly, we found that phosphorylation of the upstream S716 NDR/LATS consensus site, present only in the longest Kif23 isoform, is required for efficient phosphorylation at S814, thus revealing sequential phosphorylation at these two sites, and differential regulation of Kif23-14-3-3 interaction for the two Kif23 isoforms. Finally, we provide evidence that Kif23 is largely unphosphorylated on S814 in post-abscission midbodies, making this Kif23 post-translational modification a potential marker to probe these structures.
authors: CRBM UMR 5237, CNRS and Université de Montpellier, Montpellier, France.
authors: Didier
authors: D
authors: Fesquet
authors: CRBM UMR 5237, CNRS and Université de Montpellier, Montpellier, France.
authors: Geoffroy
authors: G
authors: De Bettignies
authors: CRBM UMR 5237, CNRS and Université de Montpellier, Montpellier, France.
authors: Michel
authors: M
authors: Bellis
authors: CRBM UMR 5237, CNRS and Université de Montpellier, Montpellier, France.
authors: Julien
authors: J
authors: Espeut
authors: CRBM UMR 5237, CNRS and Université de Montpellier, Montpellier, France.
authors: Alain
authors: A
authors: Devault
mesh_terms: D045744:Cell Line, Tumor; D006801:Humans; D008869:Microtubule-Associated Proteins / Q000378:metabolism*; D010766:Phosphorylation; D011485:Protein Binding; D020033:Protein Isoforms / Q000378:metabolism; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism*; D012694:Serine / Q000378:metabolism; D025521:Tumor Suppressor Proteins / Q000378:metabolism*
chemical_list: C092935:KIF23 protein, human; D008869:Microtubule-Associated Proteins; D020033:Protein Isoforms; D025521:Tumor Suppressor Proteins; D012694:Serine; C092745:LATS1 protein, human; C406449:LATS2 protein, human; D017346:Protein Serine-Threonine Kinases