Kendrin Is a Novel Substrate for Separase Involved in the Licensing of Centriole Duplication

Abstract

The centrosome, consisting of a pair of centrioles surrounded by pericentriolar material, directs the formation of bipolar spindles during mitosis. Aberrant centrosome number can promote chromosome instability, which is implicated in tumorigenesis. Thus, centrosome duplication needs to be tightly regulated to occur only once per cell cycle. Separase, a cysteine protease that triggers sister chromatid separation, is involved in centriole disengagement, which licenses centrosomes for the next round of duplication. However, at least two questions remain unsolved: what is the substrate relevant to the disengagement, and how does separase, activated at anaphase onset, act on the disengagement that occurs during late mitosis. Here, we show that kendrin, also named pericentrin, is cleaved by activated separase at a consensus site in vivo and in vitro, and this leads to the delayed release of kendrin from the centrosome later in mitosis. Furthermore, we demonstrate that expression of a noncleavable kendrin mutant suppresses centriole disengagement and subsequent centriole duplication. Based on these results, we propose that kendrin is a novel and crucial substrate for separase at the centrosome, protecting the engaged centrioles from premature disengagement and thereby blocking reduplication until the cell passes through mitosis.

Promoter hijack reveals pericentrin functions in mitosis and the DNA damage response

“…Alternatively, there may be some differences in the relative importance of pericentrin for forming a PCM scaffold between lymphoid cells and HeLa cells. Regarding the recently reported requirement for separase cleavage of pericentrin to allow centriole disengagement and licensing for reduplication, 19,20 as this process requires the removal of pericentrin, its loss in our knockout model is not likely to prove an impediment to M phase progression.…”

“…7,17,18 Recent findings have indicated that pericentrin cleavage by separase is required for the mitotic centriole disengagement that allows reduplication, although how its removal controls licensing is not yet established. 19,20 In Drosophila, P-element-mediated disruption of the gene encoding the pericentrin ortholog, D-PLP, led to reduced centrosomal accumulation of γ-tubulin and of other centrosome components, although no marked impact on mitosis was observed. 4 Notably, ciliary abnormalities arose in the d-plp mutant flies, a phenotype reflected in the recent description of defective olfactory cilia formation in mice with a gene trap insertion in the 5' untranslated region of the first exon of Pcnt.…”

The Centrosome and Its Duplication Cycle

“…Depletion of the C. elegans separase, sep-1, impairs the separation and consequent duplication of sperm-derived centrioles at the meiosis-mitosis transition, but subsequent cycles proceed normally (Cabral et al 2013). To date, searches for alternative separase substrates in centriole disengagement have identified kendrin/pericentrin B (Lee and Rhee 2012;Matsuo et al 2012). However, much remains to be done before we understand the nature of this process.…”

Adducin‐1 is essential for spindle pole integrity through its interaction with TPX2

“…The phosphorylation of ADD1 at S726 within the MARCKS‐related motif has been shown to decrease the binding of ADD1 to spectrin and F‐actin 10, 34. In addition, F‐actin has not been detected in centrosomes.…”

“…Pericentrin (PCNT), a PCM protein that protects engaged centrioles from premature disengagement, was identified as a crucial substrate for separase at centrosomes 9, 10. In addition, astrin and Aki1 have been shown to regulate centrosomal separase activity.…”