Regulation of Rap1 activity is required for differential adhesion, cell-type patterning and morphogenesis inDictyostelium
| Autor: | Robert R. Kay, Nicola L. Aldren, Christopher R. L. Thompson, David Traynor, Gerald Weeks, Katie Parkinson, Parvin Bolourani |
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| Rok vydání: | 2009 |
| Předmět: |
endocrine system
Cell type Cellular differentiation Molecular Sequence Data Telomere-Binding Proteins Morphogenesis Motility Biology Gene Knockout Techniques Cell Movement Cell Adhesion Animals Dictyostelium Amino Acid Sequence Cell adhesion rap1 GTP-Binding Proteins Cell Differentiation Cell Biology Cell sorting Cell biology enzymes and coenzymes (carbohydrates) Neural cell adhesion molecule Rap1 Sequence Alignment Research Article |
| Zdroj: | Journal of Cell Science. 122:335-344 |
| ISSN: | 1477-9137 0021-9533 |
| DOI: | 10.1242/jcs.036822 |
| Popis: | 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. |
| Databáze: | OpenAIRE |
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