title: Mitosis-coupled, microtubule-dependent clustering of endosomal vesicles around centrosomes.
abstract: Upon cell division, not only cells themselves but also their organelles undergo drastic shape changes, although the behaviors of organelles other than the Golgi apparatus remain poorly understood. We followed the spatiotemporal changes in the localization of transferrin receptor (TfnR) and other proteins. In early mitotic phases, a population of proteins cycling through the endocytic recycling compartment (ERC) exhibits a distinct spatiotemporal change from that of Golgi proteins. In prophase/prometaphase, when the cell surface-to-volume ratio is reaching its minimum, the ERC proteins are transiently assembled around the centrated centrosome in a microtubule- and dynein-dependent manner, and soon separated polewards into two clusters concomitant with separation of duplicated centrosomes. Electron microscopic analysis revealed that endosomal vesicles containing endocytosed transferrin cluster tightly around centrosomes without fusing with one another. As cytokinesis proceeds, the clusters gradually collapse, and the ERC proteins reassemble around the furrowing equatorial region. FRAP (fluorescence recovery after photobleaching) analyses of EGFP-TfnR-expressing cells revealed minimal membrane exchange between the endosomal clusters and other cellular compartments until anaphase/telophase, when membrane traffic resumes. Our observations indicate that ERC clustering around centrosomes plays a fundamental role in restricting membrane delivery to the plasma membrane during early mitotic phases, when the cell surface-to-volume ratio reaches its minimum.
authors: Graduate School of Pharmaceutical Sciences, Kyoto University, Kyoto, Japan.
authors: Hiroyuki
authors: H
authors: Takatsu
authors: Yohei
authors: Y
authors: Katoh
authors: Tomoko
authors: T
authors: Ueda
authors: Satoshi
authors: S
authors: Waguri
authors: Takashi
authors: T
authors: Murayama
authors: Senye
authors: S
authors: Takahashi
authors: Hye-Won
authors: HW
authors: Shin
authors: Kazuhisa
authors: K
authors: Nakayama
mesh_terms: D000705:Anaphase; D002462:Cell Membrane / Q000378:metabolism; D018385:Centrosome / Q000378:metabolism / Q000648:ultrastructure; D048749:Cytokinesis / Q000235:genetics; D004705:Endocytosis / Q000235:genetics; D011992:Endosomes / Q000378:metabolism / Q000648:ultrastructure; D049452:Green Fluorescent Proteins / Q000378:metabolism; D057809:HEK293 Cells; D006801:Humans; D026901:Membrane Transport Proteins / Q000378:metabolism; D008870:Microtubules / Q000378:metabolism / Q000648:ultrastructure; D008938:Mitosis / Q000235:genetics; D015388:Organelles / Q000378:metabolism / Q000648:ultrastructure; D011990:Receptors, Transferrin / Q000032:analysis; D008941:Spindle Apparatus / Q000648:ultrastructure
chemical_list: D026901:Membrane Transport Proteins; D011990:Receptors, Transferrin; C485184:enhanced green fluorescent protein; D049452:Green Fluorescent Proteins