Cofilin increases the bending flexibility of actin filaments: implications for severing and cell mechanics.

ABSTRACT: We determined the flexural (bending) rigidities of actin and cofilactin filaments from a cosine correlation function analysis of their thermally driven, two-dimensional fluctuations in shape. The persistence length of actin filaments is 9.8 microm, corresponding to a flexural rigidity of 0.040 pN microm(2). Cofilin binding lowers the persistence length approximately 5-fold to a value of 2.2 microm and the filament flexural rigidity to 0.0091 pN microm(2). That cofilin-decorated filaments are more flexible than native filaments despite an increased mass indicates that cofilin binding weakens and redistributes stabilizing subunit interactions of filaments. We favor a mechanism in which the increased flexibility of cofilin-decorated filaments results from the linked dissociation of filament-s

SUBMITTER: McCullough BR 

PROVIDER: S-EPMC2753234 | biostudies-literature | 2008 Sep

REPOSITORIES: biostudies-literature