title: Depolymerization of F-actin by deoxyribonuclease I.
abstract: Deoxyribonuclease I causes depolymerization of filamentous muscle actin to form a stable complex of 1 mole DNAase I:1 mole actin. The regulatory proteins tropomyosin and troponin bind to filamentous actin and slow down but do not prevent the depolymerization. In the absense of ATP, heavy meromyosin binds tightly to actin filaments and blocks completely the DNAase I: actin filament interaction. Addition of ATP releases heavy meromyosin; DNAase I is then rapidly inhibited and the actin filaments are depolymerized.
mesh_terms: D000199:Actins / Q000378:metabolism*; D000251:Adenosine Triphosphatases / Q000378:metabolism; D000255:Adenosine Triphosphate / Q000494:pharmacology; D000818:Animals; D003851:Deoxyribonucleases / Q000378:metabolism*; D015879:Myosin Subfragments / Q000494:pharmacology; D011817:Rabbits; D014335:Tropomyosin / Q000494:pharmacology; D014336:Troponin / Q000494:pharmacology; D014783:Viscosity
chemical_list: D000199:Actins; D015879:Myosin Subfragments; D014335:Tropomyosin; D014336:Troponin; D000255:Adenosine Triphosphate; D003851:Deoxyribonucleases; D000251:Adenosine Triphosphatases