Cytokinesis in multicellular organisms dictates how cells are organized in a tissue, their identities and functions. A study conducted by the Plant Reproduction and Development Laboratory (RDP - CNRS/ENS de Lyon/Inrae) and published in Science Advances , presents a quantitative analysis of cytokinesis steps in the model plant Arabidopsis using high-resolution microscopy approaches. This work describes the molecular mechanism by which the lipid signature at the membrane acts as a signal for the recruitment of the microtubule cytoskeleton during cell division in plants.
Plant cytokinesis, which fundamentally differs from that in animals, requires the outward expansion of a plasma membrane precursor named the cell plate. How the transition from a cell plate to a plasma membrane occurs remains poorly understood. Here, we report that the acquisition of plasma membrane identity occurs through lateral patterning of the phosphatidylinositol 4,5-bisphosphate PI(4,5)P2 at the newly formed cell plate membrane. There, the phosphoinositide phosphatase SAC9 emerges as a key regulator, colocalizing with and regulating the function of the microtubule-associated protein MAP65-3 at the cell plate leading zone. In sac9-3 mutant, the polar distribution of PI(4,5)P2 at the cell plate is altered, leading to ectopic recruitment of the cytokinesis apparatus and formation of an additional cell plate insertion site. We propose that at the cell plate, SAC9 drives the depletion of PI(4,5)P2, which acts as a polar cue to spatially separate cell plate expansion from the acquisition of plasma membrane identity during final step of cytokinesis.
Une signature lipidique singulière guide la cytokinèse des cellules végétales ( )", YouTube accoun En direct des labos of CNRS
ReferenceThe phosphoinositide signature guides the final step of plant cytokinesis. Alexis Lebecq, Camila Goldy, Aurélie Fangain, Elsa Gascon, Katia Berlcram, Martine Pastuglia, David Bouchez and Marie-Cécile Caillaud. DOI : 10.1126/sciadv.adf7532
illustration credits: Alexis Lebecq