The interrelationship between APC/C and Plk1 activities in centriole disengagement
UMass Chan AffiliationsDepartment of Cell and Developmental Biology
Document TypeJournal Article
Ubiquitin-Protein Ligase Complexes
Cell Cycle Proteins
Cell and Developmental Biology
MetadataShow full item record
AbstractMother-daughter centriole disengagement, the necessary first step in centriole duplication, involves Plk1 activity in early mitosis and separase activity after APC/C activity mediates securin degradation. Plk1 activity is thought to be essential and sufficient for centriole disengagement with separase activity playing a supporting but non-essential role. In separase null cells, however, centriole disengagement is substantially delayed. The ability of APC/C activity alone to mediate centriole disengagement has not been directly tested. We investigate the interrelationship between Plk1 and APC/C activities in disengaging centrioles in S or G2 HeLa and RPE1 cells, cell types that do not reduplicate centrioles when arrested in S phase. Knockdown of the interphase APC/C inhibitor Emi1 leads to centriole disengagement and reduplication of the mother centrioles, though this is slow. Strong inhibition of Plk1 activity, if any, during S does not block centriole disengagement and mother centriole reduplication in Emi1 depleted cells. Centriole disengagement depends on APC/C-Cdh1 activity, not APC/C-Cdc20 activity. Also, Plk1 and APC/C-Cdh1 activities can independently promote centriole disengagement in G2 arrested cells. Thus, Plk1 and APC/C-Cdh1 activities are independent but slow pathways for centriole disengagement. By having two slow mechanisms for disengagement working together, the cell ensures that centrioles will not prematurely separate in late G2 or early mitosis, thereby risking multipolar spindle assembly, but rather disengage in a timely fashion only late in mitosis.
Biol Open. 2012 Nov 15;1(11):1153-60. doi: 10.1242/bio.20122626. Link to article on publisher's site
Permanent Link to this Itemhttp://hdl.handle.net/20.500.14038/26441
Copyright 2012 by The Company of Biologists Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial Share Alike License (http://creativecommons.org/licenses/by-nc-sa/3.0).