dictyNews Electronic Edition Volume 36, number 15 June 3, 2011 Please submit abstracts of your papers as soon as they have been accepted for publication by sending them to dicty@northwestern.edu or by using the form at http://dictybase.org/db/cgi-bin/dictyBase/abstract_submit. Back issues of dictyNews, the Dicty Reference database and other useful information is available at dictyBase - http://dictybase.org. Follow dictyBase on twitter: http://twitter.com/dictybase ========= Abstracts ========= The LRRK2-related Roco kinase Roco2 is regulated by Rab1A and controls the actin cytoskeleton Sebastien Kicka, Zhouxin Shen, Sarah J. Annesley, Paul R. Fisher, Susan Lee, Steven Briggs and Richard A. Firtel Mol. Biol Cell, in press We identify a new pathway that is required for proper pseudopod formation. We show that Roco2, an LRRK2-related Roco kinase, is activated in response to chemoattractant stimulation and helps mediate cell polarization and chemotaxis by regulating cortical F-actin polymerization and pseudopod extension in a pathway that requires Rab1A. We found that Roco2 binds the small GTPase Rab1A as well as the F-actin crosslinking protein filamin (actin-binding protein 120, abp120) in vivo. We show that active Rab1A (Rab1A-GTP) is required for and regulates Roco2 kinase activity in vivo, and that filamin lies downstream from Roco2 to control pseudopod extension during chemotaxis and random cell motility. Therefore, our study uncovered a new signaling pathway that involves Rab1A and controls the actin cytoskeleton and pseudopod extension, and thereby, cell polarity and motility. These findings may have also implications in the regulation of other Roco kinases, including possibly LRRK2, in metazoans. Submitted by Rick Firtel [rafirtel@ucsd.edu] ============================================================== [End dictyNews, volume 36, number 15]