Answer to Question #286715 in Cell Biology for Vikas kumar caim

Question

A patient comes into your clinic with unexplained paralysis in her limbs. She has no history of neuromuscular problems. After further questioning you find that that she had taken a drug “X.” Explain the effect of a possible toxin in the drug on actin filaments that might be the cause of her paralysis.

Answer 1

Cytochalasin D and Latrunculin are both considered toxins that have been developed by certain fungi and sponges that both promote the depolymerization of filaments. Cytochalasin D is a fungal alkaloid while Latrunculin is a toxin that is secreted by sponges. Although they both result in depolymerization, they have different mechanisms. Cytochalasin D binds to the (+) end of F-actin and blocks the addition of subunits. Contrasting, Latrunculin binds to and sequesters G-actin, thus preventing it from adding to the filament end of F-actin. Upon addition to live cells, Cytochalasin D and Latrunculin disassemble the actin cytoskeleton and inhibit cell movements such as locomotion.