1. FIP5 phosphorylation during mitosis regulates apical trafficking and lumenogenesis
- Author
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Louis Cicchini, Anthony Mangan, Ben Margolis, Rytis Prekeris, and Dongying Li
- Subjects
Cytoskeleton organization ,Endosome ,Endocytic cycle ,Mitosis ,Biology ,Biochemistry ,Madin Darby Canine Kidney Cells ,Dogs ,Cell polarity ,Genetics ,Animals ,Humans ,Amino Acid Sequence ,Phosphorylation ,Molecular Biology ,Adaptor Proteins, Signal Transducing ,Cytokinesis ,Cell Membrane ,Scientific Reports ,Cell Polarity ,Apical constriction ,Apical membrane ,Cell biology ,Midbody ,Protein Transport ,Protein Processing, Post-Translational ,HeLa Cells ,Protein Binding - Abstract
Apical lumen formation is a key step during epithelial morphogenesis. The establishment of the apical lumen is a complex process that involves coordinated changes in plasma membrane composition, endocytic transport, and cytoskeleton organization. These changes are accomplished, at least in part, by the targeting and fusion of Rab11/FIP5-containing apical endosomes with the apical membrane initiation site (AMIS). Although AMIS formation and polarized transport of Rab11/FIP5-containing endosomes are crucial for the formation of a single apical lumen, the spatiotemporal regulation of this process remains poorly understood. Here, we demonstrate that the formation of the midbody during cytokinesis is a symmetry-breaking event that establishes the location of the AMIS. The interaction of FIP5 with SNX18, which is required for the formation of apical endocytic carriers, is inhibited by GSK-3 phosphorylation at FIP5-T276. Importantly, we show that FIP5-T276 phosphorylation occurs specifically during metaphase and anaphase, to ensure the fidelity and timing of FIP5-endosome targeting to the AMIS during apical lumen formation.
- Published
- 2014