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Research Database PMU-SQQUID

UNC-87, a calponin-related protein in C. elegans, antagonizes ADF/cofilin-mediated actin filament dynamics.
Yamashiro, S; Gimona, M; Ono, S;
J Cell Sci. 2007; 120(Pt 17):3022-3033
Originalarbeiten (Zeitschrift)

PMU-Authors

Gimona Mario

Abstract

Stabilization of actin filaments is critical for supporting actomyosin-based contractility and for maintaining stable cellular structures. Tropomyosin is a well-characterized ubiquitous actin stabilizer that inhibits ADF/cofilin-dependent actin depolymerization. Here, we show that UNC-87, a calponin-related Caenorhabditis elegans protein with seven calponin-like repeats, competes with ADF/cofilin for binding to actin filaments and inhibits ADF/cofilin-dependent filament severing and depolymerization in vitro. Mutations in the unc-87 gene suppress the disorganized actin phenotype in an ADF/cofilin mutant in the C. elegans body wall muscle, supporting their antagonistic roles in regulating actin stability in vivo. UNC-87 and tropomyosin exhibit synergistic effects in stabilizing actin filaments against ADF/cofilin, and direct comparison reveals that UNC-87 effectively stabilizes actin filaments at much lower concentrations than tropomyosin. However, the in vivo functions of UNC-87 and tropomyosin appear different, suggesting their distinct roles in the regulation of actomyosin assembly and cellular contractility. Our results demonstrate that actin binding via calponin-like repeats competes with ADF/cofilin-driven cytoskeletal turnover, and is critical for providing the spatiotemporal regulation of actin filament stability.


Useful keywords (using NLM MeSH Indexing)

Actin Cytoskeleton/metabolism*

Actin Depolymerizing Factors/genetics

Actin Depolymerizing Factors/metabolism*

Actins/metabolism

Animals

Caenorhabditis elegans/anatomy*

histology

Caenorhabditis elegans/metabolism*

Caenorhabditis elegans Proteins/genetics

Caenorhabditis elegans Proteins/metabolism*

Destrin/genetics

Destrin/metabolism*

Microfilament Proteins/genetics

Microfilament Proteins/metabolism

Muscle Proteins/genetics

Muscle Proteins/metabolism*

Muscles/cytology

Muscles/metabolism

Tropomyosin/metabolism


Find related publications in this database (Keywords)

actin dynamics
ADF/cofilin
calponin
tropomyosin