Link to bioRxiv paper:
http://biorxiv.org/cgi/content/short/2022.10.12.511969v1?rss=1

Authors: Bogucka-Janczi, K., Harms, G., May-Coissieux, M., Bentires-Alj, M., Thiede, B., Rajalingam, K.

Abstract:
The actin cytoskeleton is tightly controlled by RhoGTPases, actin binding proteins and nucleation-promoting factors to perform fundamental cellular functions. Here, we show that ERK3, an atypical MAPK, directly acts as a guanine nucleotide exchange factor for Cdc42 and phosphorylates the ARP3 subunit of the ARP2/3 complex at S418 to promote filopodia formation and actin polymerization, respectively. Consistently, depletion of ERK3 prevented both basal and EGF-dependent Rac1 and Cdc42 activation, maintenance of F-actin content, filopodia formation and epithelial cell migration. Further, ERK3 protein binds directly to the purified ARP2/3 complex and augments polymerization of actin in vitro. ERK3 kinase activity is required for the formation of actin-rich protrusions in mammalian cells. These findings unveil a fundamentally unique pathway employed by cells to control actin-dependent cellular functions.

Copy rights belong to original authors. Visit the link for more info

Podcast created by Paper Player, LLC