QUICK SEARCH:   [advanced] Author: Keyword(s):
Home     Help     Feedback     Subscriptions     Archive     Search     Table of Contents

First published online 6 January 2009
doi: 10.1242/jcs.036822

This Article Figures Only Full Text Full Text (PDF) Supplementary Material All Versions of this Article: jcs.036822v1 122/3/335    most recent Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Related articles in JCS Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Parkinson, K. Articles by Thompson, C. R. L. Search for Related Content PubMed PubMed Citation Articles by Parkinson, K. Articles by Thompson, C. R. L. Social Bookmarking                         What's this?

Regulation of Rap1 activity is required for differential adhesion, cell-type patterning and morphogenesis in Dictyostelium

¹ Faculty of Life Sciences, University of Manchester, Michael Smith Building, Oxford Road, Manchester M13 9PT, UK
² Department of Microbiology and Immunology, University of British Columbia, Vancouver, British Columbia, V6T 1Z3 Canada
³ MRC Laboratory of Molecular Biology, Hills Road, Cambridge CB2 2QH, UK

^* Author for correspondence (e-mail: christopher.thompson{at}manchester.ac.uk)

Accepted 13 October 2008

Regulated cell adhesion and motility have important roles during growth, development and tissue homeostasis. Consequently, great efforts have been made to identify genes that control these processes. One candidate is Rap1, as it has been implicated in the regulation of adhesion and motility in cell culture. To further study the role of Rap1 during multicellular development, we generated a mutant in a potential Rap1 GTPase activating protein (RapGAPB) in Dictyostelium. rapGAPB^– cells have increased levels of active Rap1 compared with wild-type cells, indicating that RapGAPB regulates Rap1 activity. Furthermore, rapGAPB^– cells exhibit hallmark phenotypes of other known mutants with hyperactivated Rap1, including increased substrate adhesion and abnormal F-actin distribution. However, unlike these other mutants, rapGAPB^– cells do not exhibit impaired motility or chemotaxis, indicating that RapGAPB might only regulate specific roles of Rap1. Importantly, we also found that RapGAPB regulates Rap1 activity during multicellular development and is required for normal morphogenesis. First, streams of aggregating rapGAPB^– cells break up as a result of decreased cell-cell adhesion. Second, rapGAPB^– cells exhibit cell-autonomous defects in prestalk cell patterning. Using cell-type-specific markers, we demonstrate that RapGAPB is required for the correct sorting behaviour of different cell types. Finally, we show that inactivation of RapGAPB affects prestalk and prespore cell adhesion. We therefore propose that a possible mechanism for RapGAPB-regulated cell sorting is through differential adhesion.

Key words: Differential cell adhesion, Morphogenesis, Pattern formation, Rap1, RapGAP

CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    Twitter    What's this?

Related articles in JCS:

Hidden depths to Rap1

JCS 2009 122: 304. [Full Text]  

This article has been cited by other articles:

				K. Parkinson, P. Bolourani, D. Traynor, N. L. Aldren, R. R. Kay, G. Weeks, and C. R. L. Thompson Regulation of Rap1 activity is required for differential adhesion, cell-type patterning and morphogenesis in Dictyostelium Development, February 15, 2009; 136(4): e1 - e1. [Full Text]