What would happen to treadmilling of actin if you add phallo

What would happen to treadmilling of actin if you add phalloidin to a cell? Explain your answer.

Solution

Phalloidin is a class of toxin called phallotoxin and is a bicyclic peptide. Actin is a structural protein associated with all eukaryotic cell with the exception of nematode sperm and is highly abundant, G-actin which is a monomeric, globular form of actin is the basic unit for actin fillaments. In a steady state, the fillament dynamics undergoes an assembly as well as disassembly takes place; monomer disassembly from the negative end and polymerization at the positive end is balanced which is maintained by a critical concentration of monomers in the cytosol. This process if assembly and disassembly is called \"treadmilling of actin\". Addition of phalloidin results in binding F-actin, preventing its depolymerization, thereby affecting the steady state and resulting in poisoning the cell.