SPIN90 associates with mDia1 and the Arp2/3 complex to regulate cortical actin organization.
Nat Cell Biol
; 22(7): 803-814, 2020 07.
Article
em En
| MEDLINE
| ID: mdl-32572169
ABSTRACT
Cell shape is controlled by the submembranous cortex, an actomyosin network mainly generated by two actin nucleators the Arp2/3 complex and the formin mDia1. Changes in relative nucleator activity may alter cortical organization, mechanics and cell shape. Here we investigate how nucleation-promoting factors mediate interactions between nucleators. In vitro, the nucleation-promoting factor SPIN90 promotes formation of unbranched filaments by Arp2/3, a process thought to provide the initial filament for generation of dendritic networks. Paradoxically, in cells, SPIN90 appears to favour a formin-dominated cortex. Our in vitro experiments reveal that this feature stems mainly from two mechanisms efficient recruitment of mDia1 to SPIN90-Arp2/3 nucleated filaments and formation of a ternary SPIN90-Arp2/3-mDia1 complex that greatly enhances filament nucleation. Both mechanisms yield rapidly elongating filaments with mDia1 at their barbed ends and SPIN90-Arp2/3 at their pointed ends. Thus, in networks, SPIN90 lowers branching densities and increases the proportion of long filaments elongated by mDia1.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Citoesqueleto de Actina
/
Actinas
/
Proteínas Adaptadoras de Transdução de Sinal
/
Complexo 2-3 de Proteínas Relacionadas à Actina
/
Forminas
/
Melanoma
/
Proteínas Musculares
Tipo de estudo:
Risk_factors_studies
Limite:
Animals
/
Humans
Idioma:
En
Ano de publicação:
2020
Tipo de documento:
Article