Polarity sorting drives remodeling of actin-myosin networks.
J Cell Sci
; 132(4)2018 12 13.
Article
en En
| MEDLINE
| ID: mdl-30404824
ABSTRACT
Cytoskeletal networks of actin filaments and myosin motors drive many dynamic cell processes. A key characteristic of these networks is their contractility. Despite intense experimental and theoretical efforts, it is not clear what mechanism favors network contraction over expansion. Recent work points to a dominant role for the nonlinear mechanical response of actin filaments, which can withstand stretching but buckle upon compression. Here, we present an alternative mechanism. We study how interactions between actin and myosin-2 at the single-filament level translate into contraction at the network scale by performing time-lapse imaging on reconstituted quasi-2D networks mimicking the cell cortex. We observe myosin end-dwelling after it runs processively along actin filaments. This leads to transport and clustering of actin filament ends and the formation of transiently stable bipolar structures. Further, we show that myosin-driven polarity sorting produces polar actin asters, which act as contractile nodes that drive contraction in crosslinked networks. Computer simulations comparing the roles of the end-dwelling mechanism and a buckling-dependent mechanism show that the relative contribution of end-dwelling contraction increases as the network mesh-size decreases.
Palabras clave
Texto completo:
1
Colección:
01-internacional
Banco de datos:
MEDLINE
Asunto principal:
Citoesqueleto
/
Simulación por Computador
/
Actinas
/
Miosinas
Tipo de estudio:
Prognostic_studies
Idioma:
En
Revista:
J Cell Sci
Año:
2018
Tipo del documento:
Article
País de afiliación:
Países Bajos