RT Journal Article
SR Electronic
T1 Pulsatile actomyosin contractions underlie Par polarity during the neuroblast polarity cycle
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 2021.01.14.426740
DO 10.1101/2021.01.14.426740
A1 Oon, Chet Huan
A1 Prehoda, Kenneth E.
YR 2021
UL http://biorxiv.org/content/early/2021/01/15/2021.01.14.426740.abstract
AB The Par complex is polarized to the apical cortex of asymmetrically dividing Drosophila neuroblasts. Previously we showed that Par proteins are polarized by apically directed cortical movements that require F-actin (Oon and Prehoda, 2019). Here we report the discovery of cortical actin pulses that begin before the Par complex is recruited to the cell cortex and ultimately become tightly coupled to Par protein dynamics. Pulses are initially unoriented in interphase but are rapidly directed towards the apical pole in early mitosis, shortly before the Par protein aPKC accumulates on the cortex. The movements of cortical aPKC that lead to its polarization are precisely correlated with cortical actin pulses and F-actin disruption coincides with immediate loss of movement followed by depolarization. We find that myosin II is a component of the cortical pulses, suggesting that actomyosin pulsatile contractions initiate and maintain apical Par polarity during the neuroblast polarity cycle.Competing Interest StatementThe authors have declared no competing interest.