The motile beta/IC1 subunit of sea urchin sperm outer arm dynein does not form a rigor bond
UMass Chan Affiliations
Department of Cell BiologyDocument Type
Journal ArticlePublication Date
1992-09-01Keywords
Adenosine TriphosphateAnimals
Centrifugation, Density Gradient
Dynein ATPase
Hydrolysis
Male
Microtubules
Osmolar Concentration
Sea Urchins
Sperm Tail
Tetrahymena
Amino Acids, Peptides, and Proteins
Animal Experimentation and Research
Cell Biology
Cells
Enzymes and Coenzymes
Urogenital System
Metadata
Show full item recordAbstract
We used in vitro translocation and cosedimentation assays to study the microtubule binding properties of sea urchin sperm outer arm dynein and its beta/IC1 subunit. Microtubules glided on glass-absorbed sea urchin dynein for a period of time directly proportional to the initial MgATP2- concentration and then detached when 70-95% of the MgATP2- was hydrolyzed. Detachment resulted from MgATP2- depletion, because (a) perfusion with fresh buffer containing MgATP2- reconstituted binding and gliding, (b) microtubules glided many minutes with an ATP-regenerating system at ATP concentrations which alone supported gliding for only 1-2 min, and (c) microtubules detached upon total hydrolysis of ATP by an ATP-removal system. The products of ATP hydrolysis antagonized binding and gliding; as little as a threefold excess of ADP/Pi over ATP resulted in complete loss of microtubule binding and translocation by the beta/IC1 subunit. In contrast to the situation with sea urchin dynein, microtubules ceased gliding but remained bound to glass-absorbed Tetrahymena outer arm dynein when MgATP2- was exhausted. Cosedimentation assays showed that Tetrahymena outer arm dynein sedimented with microtubules in an ATP-sensitive manner, as previously reported (Porter, M.E., and K. A. Johnson. J. Biol. Chem. 258: 6575-6581). However, the beta/IC1 subunit of sea urchin dynein did not cosediment with microtubules in the absence of ATP. Thus, this subunit, while capable of generating motility, lacks both structural and rigor-type microtubule binding.Source
J Cell Biol. 1992 Sep;118(5):1177-88.
DOI
10.1083/jcb.118.5.1177Permanent Link to this Item
http://hdl.handle.net/20.500.14038/26570PubMed ID
1387405Related Resources
ae974a485f413a2113503eed53cd6c53
10.1083/jcb.118.5.1177