Yeast Rsp5 ubiquitin ligase affects the actin cytoskeleton in vivo and in vitro.
Eur J Cell Biol
; 90(12): 1016-28, 2011 Dec.
Article
em En
| MEDLINE
| ID: mdl-22000681
ABSTRACT
Yeast Rsp5 ubiquitin ligase is involved in several cellular processes, including endocytosis. Actin patches are sites of endocytosis, a process involving actin assembly and disassembly. Here we show Rsp5 localization in cortical patches and demonstrate its involvement in actin cytoskeleton organization and dynamics. We found that the Rsp5-F1-GFP2 N-terminal fragment and full length GFP-Rsp5 were recruited to peripheral patches that temporarily co-localized with Abp1-mCherry, a marker of actin patches. Actin cytoskeleton organization was defective in a strain lacking RSP5 or overexpressing RSP5, and this phenotype was accompanied by morphological abnormalities. Overexpression of RSP5 caused hypersensitivity of cells to Latrunculin A, an actin-depolymerizing drug and was toxic to cells lacking Las17, an activator of actin nucleation. Moreover, Rsp5 was required for efficient actin polymerization in a whole cell extract based in vitro system. Rsp5 interacted with Las17 and Las17-binding proteins, Lsb1 and Lsb2, in a GST-Rsp5-WW2/3 pull down assay. Rsp5 ubiquitinated Lsb1-HA and Lsb2-HA without directing them for degradation. Overexpression of RSP5 increased the cellular level of HA-Las17 in wild type and in lsb1Δ lsb2Δ strains in which the basal level of Las17 was already elevated. This increase was prevented in a strain devoid of Las17-binding protein Sla1 which is also a target of Rsp5 ubiquitination. Thus, Rsp5 together with Lsb1, Lsb2 and Sla1 regulate the level of Las17, an important activator of actin polymerization.
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Base de dados:
MEDLINE
Assunto principal:
Saccharomyces cerevisiae
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Citoesqueleto
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Citoesqueleto de Actina
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Proteínas de Saccharomyces cerevisiae
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Complexos Ubiquitina-Proteína Ligase
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Complexos Endossomais de Distribuição Requeridos para Transporte
Limite:
Humans
Idioma:
En
Ano de publicação:
2011
Tipo de documento:
Article