Actin Filaments and Accessory Proteins

Vocabulary flashcards defining the major accessory proteins of the actin cytoskeleton and their functional roles.

Formin

An actin accessory protein that nucleates assembly and remains associated with the growing plus end.

Arp2/3 complex

An actin accessory protein complex that nucleates assembly to form a web and remains associated with the minus end.

Thymosin

An actin accessory protein that binds subunits and prevents assembly.

Profilin

An actin accessory protein that binds subunits and speeds elongation.

Tropomodulin

An actin accessory protein that prevents assembly and disassembly at the minus end.

Cofilin

An actin accessory protein that binds ADP-actin filaments and accelerates disassembly.

Gelsolin

An actin accessory protein that severs filaments and binds to the plus end.

Capping protein

An actin accessory protein that prevents assembly and disassembly at the plus end.

Tropomyosin

An actin accessory protein that stabilizes actin filaments.

Fimbrin

An actin accessory protein involved in filament bundling.

a-actinin

An actin accessory protein involved in filament bundling and cross-linking.

Filamin

An actin accessory protein involved in filament cross-linking.

Spectrin

An actin accessory protein involved in filament cross-linking and attachment to membranes.

ERM

An actin accessory protein involved in attachment of actin filaments to the plasma membrane.

Actin cytoskeleton accessory proteins

Major accessory proteins (excluding myosin motor proteins) that regulate actin filament nucleation, assembly, disassembly, stabilization, bundling, cross-linking, and membrane attachment.