Journal
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
Volume 101, Issue 6, Pages 1491-1495Publisher
NATL ACAD SCIENCES
DOI: 10.1073/pnas.2637011100
Keywords
-
Categories
Funding
- NIAMS NIH HHS [P01 AR042895, P01 AR 42895-10] Funding Source: Medline
- NIGMS NIH HHS [F32 GM067403, R01 GM038499, GM 67403-01] Funding Source: Medline
Ask authors/readers for more resources
The motor protein cytoplasmic dynein is responsible for most of the minus-end-directed microtubule traffic within cells. Dynein contains four evolutionarily conserved AAA (ATPase associated with various cellular activities) domains that are thought to bind nucleotide; the role of nucleotide binding and hydrolysis in each of these four AAA domains has constituted an important and unresolved question in understanding dynein's mechanism. Using Saccharomyces cerevisiae cytoplasmic dynein as a model system, we mutagenized residues involved in nucleotide binding or hydrolysis in the four AAA domains and examined the ability of the mutant dyneins to mediate nuclear segregation in vivo and to bind microtubules in vitro. Our analysis shows that an AAA1 hydrolysis mutant blocks dynein function, whereas a triple AAA2/3/4 hydrolysis mutant does not, suggesting that nucleotide binding is required at only one site. We also show that nucleotide binding at AAA3, but not hydrolysis, is essential for motor activity in vivo and ATIP-induced dissociation of dynein from microtubules, suggesting that this domain acts as a critical allosteric site. In contrast, mutations in AAA2 cause subtle defects in dynein function, whereas mutation in AAA4 produce no obvious defects. These results show that the four conserved dynein AAA domains have distinct functions in dynein's mechanochemical cycle.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available