A non-canonical function for Centromere-associated protein-E controls centrosome integrity and orientation of cell division

Mikito Owa,Brian Dynlacht

doi:10.1038/s42003-021-01861-4

Abstract

Centromere-associated protein-E (CENP-E) is a kinesin motor localizing at kinetochores. Although its mitotic functions have been well studied, it has been challenging to investigate direct consequences of CENP-E removal using conventional methods because CENP-E depletion resulted in mitotic arrest. In this study, we harnessed an auxin-inducible degron system to achieve acute degradation of CENP-E. We revealed a kinetochore-independent role for CENP-E that removes pericentriolar material 1 (PCM1) from centrosomes in late S/early G2 phase. After acute loss of CENP-E, centrosomal Polo-like kinase 1 (Plk1) localization is abrogated through accumulation of PCM1, resulting in aberrant phosphorylation and destabilization of centrosomes, which triggers shortened astral microtubules and oblique cell divisions. Furthermore, we also observed centrosome and cell division defects in cells from a microcephaly patient with mutations in CENPE. Orientation of cell division is deregulated in some microcephalic patients, and our unanticipated findings provide additional insights into how microcephaly can result from centrosomal defects.

Highlights

Centromere-associated protein-E (CENP-E) is a kinesin motor localizing at kinetochores
Western blotting of lysates from synchronized wild-type RPE-1 cells confirmed that cytoplasmic CENP-E levels were elevated in late S/G2 phase, and they peaked in mitosis (Fig. 1a)
We found that pericentriolar material 1 (PCM1) depletion rescued the reduction in centrosomal Plk[1] provoked by loss of CENP-E (Fig. 7a, b), suggesting that the accumulation of PCM1 in CENP-E KO cells is directly responsible for perturbing Plk[1] recruitment to centrosomes

Summary

Introduction

Centromere-associated protein-E (CENP-E) is a kinesin motor localizing at kinetochores. 1234567890():,; The centrosome is an organizing center for microtubules (MTs) in metazoan cells This organelle functions as a hub for MT-based protein transport during interphase, and it organizes spindle poles in mitosis. Centriolar satellites, dense granules that consist of multiple proteins essential for controlling centriole duplication, are scattered around centrosomes[2,3] These granules are anchored on microtubules (MTs) through a scaffold protein, pericentriolar material 1 (PCM1; despite its name, this is not a component of the PCM). Plk[1] accumulates on the centrosome in prophase, where it phosphorylates PCM components, including pericentrin (PCNT) and Wdr6212,13 These modifications accelerate PCM expansion and formation of robust astral MTs, which anchor the cell cortex to maintain spindle orientation. We have unveiled an unanticipated role for CENP-E in centrosome dynamics and have linked it to mechanisms that result in microcephaly

Methods

Results

Conclusion