Elucidating key Motifs required for Arp2/3-dependent and independent actin nucleation by las17/WASP

 

Ellen G. Allwood, Joe J. Tyler, Agnieszka N. Urbanek, Iwona I. Smaczynska-de Rooij, Kathryn R. Ayscough

PloS ONE
2016 vol: 11 issue: 9 pp: e0163177 doi: 10.1371/journal.pone.0163177

Abstract

Actin nucleation is the key rate limiting step in the process of actin polymerization, and tight regulation of this process is critical to ensure actin filaments form only at specific times and at defined regions of the cell. Arp2/3 is a well-characterised protein complex that can promote nucleation of new filaments, though its activity requires additional nucleation promotion factors (NPFs). The best recognized of these factors are the WASP family of proteins that contain binding motifs for both monomeric actin and for Arp2/3. Previously we demonstrated that the yeast WASP homologue, Las17, in addition to activating Arp2/3 can also nucleate actin filaments de novo, independently of Arp2/3. This activity is dependent on its polyproline rich region. Through biochemical and in vivo analysis we have now identified key motifs within the polyproline region that are required for nucleation and elongation of actin filaments, and have addressed the role of the WH2 domain in the context of actin nucleation without Arp2/3. We have also demonstrated that full length Las17 is able to bind liposomes giving rise to the possibility of direct linkage of nascent actin filaments to specific membrane sites to which Las17 has been recruited. Overall, we propose that Las17 functions as the key initiator of de novo actin filament formation at endocytic sites by nucleating, elongating and tethering nascent filaments which then serve as a platform for Arp2/3 recruitment and function.

View Publication

Topics: Nucleation, Proline, Actins, Actin polymerization, Yeast, Actin filaments, Polymerization, Nuclear actin filaments, Monolith – MicroScale Thermophoresis, MST, Proteins, Publications

 

 

Previous Article
Quantitative analysis of protease recognition by inhibitors in plasma using Microscale Thermophoresis
Quantitative analysis of protease recognition by inhibitors in plasma using Microscale Thermophoresis

Up next
Protein kinase C controls lysosome biogenesis independently of mTORC1
Protein kinase C controls lysosome biogenesis independently of mTORC1

×

Sign up to receive
the latest NanoTemper news, product updates, event announcements and more

First Name
Last Name
Company Name
State
Province
State
Region
State
Canton
Agree to Privacy Policy*
*I have fully read, understood and agree to the Privacy Policy. I accept the storing and processing of my personal data by NanoTemper as described in the Privacy Policy.

By completing this form, you provide us consent to contact you with educational content, news and information about our products, services and events. You may unsubscribe at any time.
Thank you!
Error - something went wrong!