Welcome to the new version of CaltechAUTHORS. Login is currently restricted to library staff. If you notice any issues, please email coda@library.caltech.edu
Published November 14, 2011 | Published + Supplemental Material
Journal Article Open

Sticky/Citron kinase maintains proper RhoA localization at the cleavage site during cytokinesis

Abstract

In many organisms, the small guanosine triphosphatase RhoA controls assembly and contraction of the actomyosin ring during cytokinesis by activating different effectors. Although the role of some RhoA effectors like formins and Rho kinase is reasonably understood, the functions of another putative effector, Citron kinase (CIT-K), are still debated. In this paper, we show that, contrary to previous models, the Drosophila melanogaster CIT-K orthologue Sticky (Sti) does not require interaction with RhoA to localize to the cleavage site. Instead, RhoA fails to form a compact ring in late cytokinesis after Sti depletion, and this function requires Sti kinase activity. Moreover, we found that the Sti Citron-Nik1 homology domain interacts with RhoA regardless of its status, indicating that Sti is not a canonical RhoA effector. Finally, Sti depletion caused an increase of phosphorylated myosin regulatory light chain at the cleavage site in late cytokinesis. We propose that Sti/CIT-K maintains correct RhoA localization at the cleavage site, which is necessary for proper RhoA activity and contractile ring dynamics.

Additional Information

© 2011 Bassi et al. This article is distributed under the terms of an Attribution–Noncommercial–Share Alike–No Mirror Sites license for the first six months after the publication date (see http://www.rupress.org/terms). After six months it is available under a Creative Commons License (Attribution–Noncommercial–Share Alike 3.0 Unported license, as described at http://creativecommons.org/licenses/by-nc-sa/3.0/). Submitted: 25 May 2011. Accepted: 17 October 2011. We would like to thank A. Miller and B. Bement for the Rhotekin RBD plasmid, R. Ward for Sqh1P and Sqh2P antibodies, and T. Takeda for the Sqh::GFP cell line. We are also grateful to M. Savoian for helpful suggestions and T. Takeda for critical reading of the manuscript. The Rho1 antibody was obtained from the Developmental Studies Hybridoma Bank. This work was supported by a Cancer Research UK grant (C12296/A12541) and a Newton Trust Research grant to P.P. D'Avino. Z.I. Bassi is supported by a Gwynaeth Pretty PhD fellowship of the Department of Pathology of the University of Cambridge. K.J. Verbrugghe and work in the Glover laboratory were supported by a Cancer Research UK program grant.

Attached Files

Published - jcb_201105136.pdf

Supplemental Material - Figure.ppt

Supplemental Material - Figure3.ppt

Supplemental Material - Figure4.ppt

Supplemental Material - Figure5.ppt

Supplemental Material - FigureS2.ppt

Supplemental Material - JCB_201105136_V1.mov

Supplemental Material - JCB_201105136_V2.mov

Files

jcb_201105136.pdf
Files (4.9 MB)
Name Size Download all
md5:f71e22c76cb168e356e8463909d28c2a
246.3 kB Download
md5:d797cb8bcea08c59031beec24e32616c
859.6 kB Download
md5:6752640f108c3d46b020b646d2e09d5b
295.4 kB Download
md5:9e6106f013d40991320d420e6ac46b2a
226.8 kB Download
md5:8e335a5f5303aa48a7ffea202863243c
2.3 MB Preview Download
md5:24495f9e2798bcfe7f49d8a6d10e5862
246.3 kB Download
md5:e1bef85417f7254a0868bf3213a37141
276.1 kB Download
md5:3df0fb0d6b11f5e6d4a2f06f7dcfd284
365.5 kB Download

Additional details

Created:
August 19, 2023
Modified:
October 20, 2023