RAB-11 permissively regulates spindle alignment by modulating metaphase microtubule dynamics in Caenorhabditis elegans early embryos.
Alignment of the mitotic spindle along a preformed axis of polarity is crucial for generating cell diversity in many organisms, yet little is known about the role of the endomembrane system in this process. RAB-11 is a small GTPase enriched in recycling endosomes. When we depleted RAB-11 by RNAi in Caenorhabditis elegans, the spindle of the one-cell embryo failed to align along the axis of polarity in metaphase and underwent violent movements in anaphase. The distance between astral microtubules ends and the anterior cortex was significantly increased in rab-11(RNAi) embryos specifically during metaphase, possibly accounting for the observed spindle alignment defects. Additionally, we found that normal ER morphology requires functional RAB-11, particularly during metaphase. We hypothesize that RAB-11, in conjunction with the ER, acts to regulate cell cycle-specific changes in astral microtubule length to ensure proper spindle alignment in Caenorhabditis elegans early embryos.
Zhang
Haining
H
Laboratory of Genetics, University of Wisconsin, Madison, WI 53706, USA.
Squirrell
Jayne M
JM
White
John G
JG
D000705:Anaphase / Q000187:drug effects; D000818:Animals; D017173:Caenorhabditis elegans / Q000166:cytology* / Q000187:drug effects / Q000196:embryology* / Q000235:genetics; D029742:Caenorhabditis elegans Proteins / Q000378:metabolism; D016764:Cell Polarity / Q000187:drug effects; D004625:Embryo, Nonmammalian / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism; D004721:Endoplasmic Reticulum / Q000187:drug effects / Q000378:metabolism; D044385:GTP-Binding Protein alpha Subunits / Q000378:metabolism; D017238:Genes, Helminth; D008677:Metaphase / Q000187:drug effects; D008870:Microtubules / Q000187:drug effects / Q000378:metabolism*; D008954:Models, Biological; D015739:Nocodazole / Q000494:pharmacology; D034622:RNA Interference / Q000187:drug effects; D008941:Spindle Apparatus / Q000187:drug effects / Q000378:metabolism*; D020691:rab GTP-Binding Proteins / Q000378:metabolism*; D000099193:rab11 GTP-Binding Proteins
D029742:Caenorhabditis elegans Proteins; D044385:GTP-Binding Protein alpha Subunits; D015739:Nocodazole; D020691:rab GTP-Binding Proteins; D000099193:rab11 GTP-Binding Proteins; C475458:G protein regulator 1, C elegans; C475459:G protein regulator 2, C elegans