Abstract
Listeria monocytogenes is a bacterial parasite that uses host proteins to assemble an Arp2/3-dependent actin comet tail to power its movement through the host cell. Initiation of comet tail assembly is more efficient in cytosol than it is under defined conditions, indicating that unknown factors contribute to the reaction. We therefore fractionated cytosol and identified CRMP-1 as a factor that facilitates Arp2/3-dependent Listeria actin cloud formation in the presence of Arp2/3 and actin alone. It also scored as an important factor for Listeria actin comet tail formation in brain cytosol. CRMP-1 does not nucleate actin assembly on its own, nor does it directly activate the Arp2/3 complex. Rather, CRMP-1 scored as an auxiliary factor that promoted the ability of Listeria ActA protein to activate the Arp2/3 complex to trigger actin assembly. CRMP-1 is one member of a family of five related proteins that modulate cell motility in response to extracellular signals. Our results demonstrate an important role for CRMP-1 in Listeria actin comet tail formation and open the possibility that CRMP-1 controls cell motility by modulating Arp2/3 activation.
Highlights
The actin comet tail of Listeria monocytogenes is the most extensively characterized, physiologically relevant actin network
Identification of CRMP-1 as a New Factor for Listeria Actin Tail Formation—Previous work demonstrated that brain cytosol contains factors that associate with the Listeria cell surface and promote Arp2/3-dependent actin cloud formation [5]
We identified CRMP-1 as a factor that promotes Arp2/3-dependent Listeria actin cloud and comet tail formation (Fig. 1)
Summary
Listeria monocytogenes is a bacterial parasite that uses host proteins to assemble an Arp2/3-dependent actin comet tail to power its movement through the host cell. CRMP-1 scored as an auxiliary factor that promoted the ability of Listeria ActA protein to activate the Arp2/3 complex to trigger actin assembly. Our results demonstrate an important role for CRMP-1 in Listeria actin comet tail formation and open the possibility that CRMP-1 controls cell motility by modulating Arp2/3 activation. Driven by actin polymerization, which is assembled by frequent, Arp2/3-dependent actin nucleation reactions to form a Listeria actin comet tail [3]. We identified collapsin response mediator protein-1 (CRMP1) as one factor that enhances Listeria actin cloud assembly and characterized its basic biochemistry
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
