Microfilaments ?

Question

2. Microfilaments form when tubulin dimers polymerize into a long cylindrical structure. Let us say that it takes 20secs for a 20nm microfilament to form in a test tube at 20°C. Make an informed prediction: (A) What would happen to the length of the microfilament if I added a drug that hydrolyzes GTP into GDP into the test tube? (B) What would happen to the length of the filament if I added XMAP215 to the test tube? Explain your reasoning.

Answer 1

a: it would extend more prominently, as MF growth is reliant on GDP availability.  Reference Padlicky 2002 for MF growth in pseudopods.  b: nothing, specific to XMAP, as it is involved in MT growth at the (+) end of the centriole.