Effector-mediated ERM activation locally inhibits RhoA activity to shape the apical cell domain
| Autor: | Andrew Lombardo, Cécile Sauvanet, David J. McDermitt, Riasat Zaman, Raghuvir Viswanatha, Valerie Awad, Anthony Bretscher, Locke Ezra-Ros Bonomo |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2021 |
| Předmět: |
Myosin light-chain kinase
RHOA genetic structures macromolecular substances Biology Article 03 medical and health sciences 0302 clinical medicine Ezrin stomatognathic system Humans Phosphorylation Gene knockout Actin Cytoskeleton 030304 developmental biology 0303 health sciences Polarity Effector Cell Membrane Microfilament Proteins Membrane Proteins Epithelial Cells Cell Biology biochemical phenomena metabolism and nutrition Actin cytoskeleton Cell biology Actin Cytoskeleton Cytoskeletal Proteins biology.protein rhoA GTP-Binding Protein 030217 neurology & neurosurgery HeLa Cells |
| Zdroj: | The Journal of Cell Biology |
| ISSN: | 1540-8140 0021-9525 |
| Popis: | Zaman and Lombardo et al. characterize cells lacking all ERM proteins or their activating kinases. This reveals that active ERMs are local negative regulators of RhoA necessary to mediate the architecture of the apical domain. Activated ezrin-radixin-moesin (ERM) proteins link the plasma membrane to the actin cytoskeleton to generate apical structures, including microvilli. Among many kinases implicated in ERM activation are the homologues LOK and SLK. CRISPR/Cas9 was used to knock out all ERM proteins or LOK/SLK in human cells. LOK/SLK knockout eliminates all ERM-activating phosphorylation. The apical domains of cells lacking LOK/SLK or ERMs are strikingly similar and selectively altered, with loss of microvilli and with junctional actin replaced by ectopic myosin-II–containing apical contractile structures. Constitutively active ezrin can reverse the phenotypes of either ERM or LOK/SLK knockouts, indicating that a central function of LOK/SLK is to activate ERMs. Both knockout lines have elevated active RhoA with concomitant enhanced myosin light chain phosphorylation, revealing that active ERMs are negative regulators of RhoA. As RhoA-GTP activates LOK/SLK to activate ERM proteins, the ability of active ERMs to negatively regulate RhoA-GTP represents a novel local feedback loop necessary for the proper apical morphology of epithelial cells. |
| Databáze: | OpenAIRE |
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