Issues

Two Xenopus (x) MELK (Maternal Embryonic Leucine zipper Kinase) subpopulations have distinct requirements for cell–cell contacts for their localization at the cell cortex. xMELK and C-cadherin do not concentrate at the cortex if the cell–cell contacts are disrupted. Interestingly, in both epithelial and mesenchyme-like cytokinetic cells, xMELK, but not C-cadherin, is localized at the cell periphery. This indicates that the cortical localization of xMELK during cytokinesis is independent of cell–cell contacts. In cells that were allowed to re-aggregate, new cell–cell contacts formed and xMELK was found concentrated at the newly formed cell–cell contacts. Altogether, these results indicate that interphase MELK (iMELK) and mitotic MELK (mMELK) differ not only in their spatio-temporal localization, but also in their requirement for cell–cell contacts. These results show that iMELK localization is dependent on cell–cell contacts and that mMELK relocalizes at the cell cortex during cytokinesis. Anti-xMELK, red; anti-C-cadherin, green; DNA, blue. Scale bars: 20 µm. See the article by Chartrain et al. (doi: 10.1242/bio.20136080).