The regulation of molecular motors is an important cellular problem, as motility in the absence of cargo results in futile adenosine triphosphate hydrolysis. When not transporting cargo, the microtubule (MT)-based motor Kinesin-1 is kept inactive as a result of a folded conformation that allows autoinhibition of the N-terminal motor by the C-terminal tail. The simplest model of Kinesin-1 activation posits that cargo binding to nonmotor regions relieves autoinhibition. In this study, we show that binding of the c-Jun N-terminal kinase–interacting protein 1 (JIP1) cargo protein is not sufficient to activate Kinesin-1. Because two regions of the Kinesin-1 tail are required for autoinhibition, we searched for a second molecule that contributes to activation of the motor. We identified fasciculation and elongation protein ζ1 (FEZ1) as a binding partner of kinesin heavy chain. We show that binding of JIP1 and FEZ1 to Kinesin-1 is sufficient to activate the motor for MT binding and motility. These results provide the first demonstration of the activation of a MT-based motor by cellular binding partners.
Two binding partners cooperate to activate the molecular motor Kinesin-1
T. L. Blasius,Dawen Cai,Gloria T. Jih,Christopher P. Toret,K. Verhey
Published 2007 in Journal of Cell Biology
ABSTRACT
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- Publication year
2007
- Venue
Journal of Cell Biology
- Publication date
2007-01-01
- Fields of study
Biology, Medicine
- Identifiers
- External record
- Source metadata
Semantic Scholar, PubMed
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