title: Regulatory ATPase sites of cytoplasmic dynein affect processivity and force generation.
abstract: The heavy chain of cytoplasmic dynein contains four nucleotide-binding domains referred to as AAA1-AAA4, with the first domain (AAA1) being the main ATP hydrolytic site. Although previous studies have proposed regulatory roles for AAA3 and AAA4, the role of ATP hydrolysis at these sites remains elusive. Here, we have analyzed the single molecule motility properties of yeast cytoplasmic dynein mutants bearing mutations that prevent ATP hydrolysis at AAA3 or AAA4. Both mutants remain processive, but the AAA4 mutant exhibits a surprising increase in processivity due to its tighter affinity for microtubules. In addition to changes in motility characteristics, AAA3 and AAA4 mutants produce less maximal force than wild-type dynein. These results indicate that the nucleotide binding state at AAA3 and AAA4 can allosterically modulate microtubule binding affinity and affect dynein processivity and force production.
authors.affiliation: Howard Hughes Medical Institute, University of California, San Francisco, California 94158-2517, USA.
authors.forename: Carol
authors.initials: C
authors.lastname: Cho
authors.forename: Samara L
authors.initials: SL
authors.lastname: Reck-Peterson
authors.forename: Ronald D
authors.initials: RD
authors.lastname: Vale
mesh_terms: D000251:Adenosine Triphosphatases / Q000737:chemistry*; D000255:Adenosine Triphosphate / Q000737:chemistry; D000495:Allosteric Site; D003593:Cytoplasm / Q000378:metabolism*; D019281:Dimerization; D004398:Dyneins / Q000737:chemistry* / Q000235:genetics; D006868:Hydrolysis; D007700:Kinetics; D008954:Models, Biological; D008968:Molecular Conformation; D009154:Mutation; D009711:Nucleotides / Q000737:chemistry; D011485:Protein Binding; D012441:Saccharomyces cerevisiae; D013314:Stress, Mechanical
chemical_list: D009711:Nucleotides; D000255:Adenosine Triphosphate; D000251:Adenosine Triphosphatases; D004398:Dyneins