2. Microfilament MF A MFS are made of actin and involved in cell motility. o Using atP, g-actin polymerizes to form MF(F-actin) s on actin molecule NH COOH ATP (ADP when minus end2. Microfilament, MF A. MFs are made of actin and involved in cell motility. ❖Using ATP, G-actin polymerizes to form MF(F-actin)