​Actin dynamics in cells is dependent on several actin-binding proteins. Given below are actin-binding proteins in Column X and their typical function in Column Y.

​Which one of the following options represents all correct matches between Column X and Column Y?​

Correct option is B

Sol.

• A. Formin (III): Nucleates assembly of linear actin filaments and remains associated with the growing plus end of the filament.

• B. Arp2/3 complex (I): Nucleates actin assembly and forms branched actin networks essential for lamellipodia formation.

• C. Cofilin (IV): Binds ADP-actin filaments and accelerates filament disassembly by severing and depolymerizing.

• D. Tropomyosin (II): Stabilizes actin filaments and modulates binding of other accessory proteins, preventing disassembly.

Information Booster:

• Actin dynamics are critical for cell shape, motility, and intracellular transport.

• Formins facilitate formation of straight, unbranched actin filaments.

• Arp2/3 complex initiates branched actin filament networks for cellular protrusions.

• Cofilin promotes turnover of actin filaments, crucial for remodeling the cytoskeleton.

• Tropomyosin stabilizes filaments and regulates access of other actin-binding proteins.