title: The AAA3 domain of cytoplasmic dynein acts as a switch to facilitate microtubule release.
abstract: Cytoplasmic dynein is an AAA+ motor responsible for intracellular cargo transport and force generation along microtubules (MTs). Unlike kinesin and myosin, dynein contains multiple ATPase subunits, with AAA1 serving as the primary catalytic site. ATPase activity at AAA3 is also essential for robust motility, but its role in dynein's mechanochemical cycle remains unclear. Here, we introduced transient pauses in Saccharomyces cerevisiae dynein motility by using a slowly hydrolyzing ATP analog. Analysis of pausing behavior revealed that AAA3 hydrolyzes nucleotide an order of magnitude more slowly than AAA1, and the two sites do not coordinate. ATPase mutations to AAA3 abolish the ability of dynein to modulate MT release. Nucleotide hydrolysis at AAA3 lifts this 'MT gate' to allow fast motility. These results suggest that AAA3 acts as a switch that repurposes cytoplasmic dynein for fast cargo transport and MT-anchoring tasks in cells.
authors.affiliation: Biophysics Graduate Group, University of California, Berkeley, Berkeley, California, USA.
authors.forename: Mark A
authors.initials: MA
authors.lastname: DeWitt
authors.affiliation: Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, California, USA.
authors.forename: Caroline A
authors.initials: CA
authors.lastname: Cypranowska
authors.affiliation: Biophysics Graduate Group, University of California, Berkeley, Berkeley, California, USA.
authors.forename: Frank B
authors.initials: FB
authors.lastname: Cleary
authors.affiliation: Biophysics Graduate Group, University of California, Berkeley, Berkeley, California, USA.
authors.forename: Vladislav
authors.initials: V
authors.lastname: Belyy
authors.affiliation: 1] Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, California, USA. [2] Department of Physics, University of California, Berkeley, Berkeley, California, USA.
authors.forename: Ahmet
authors.initials: A
authors.lastname: Yildiz
mesh_terms: D000255:Adenosine Triphosphate / Q000378:metabolism; D020134:Catalytic Domain; D056445:Cytoplasmic Dyneins / Q000378:metabolism*; D006868:Hydrolysis; D046911:Macromolecular Substances / Q000378:metabolism*; D008870:Microtubules / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000201:enzymology* / Q000378:metabolism
chemical_list: D046911:Macromolecular Substances; D000255:Adenosine Triphosphate; D056445:Cytoplasmic Dyneins