Phosphotransferases associated with the regulation of kinesin motor activity.
Kinesin, a plus-end-directed microtubule motor protein, functions in concert with accessory factors that have been shown to regulate enzyme activity and may also provide cargo specificity. This report identifies teh 79-kDa kinesin-associated phosphoprotein as a phosphoisoform of kinesin light chain. Increased phosphorylation of this light chain isoform is sufficient to account for the increase in kinesin-mediated microtubule-gliding activity. Additionally, it was found that the degree of phosphorylation of this isoform is regulated by a 100-kDa kinase and 150-kDa type 1 phosphatase. Both the kinesin light chain kinase and phosphatase co-purify with the kinesin heavy chain, suggesting that kinesin exists in a large complex capable of self-regulation.
Lindesmith
L
L
Department of Cell Biology, Duke University Medical Center, Durham, North Carolina 27710, USA.
McIlvain
J M
JM
Argon
Y
Y
Sheetz
M P
MP
D000818:Animals; D002460:Cell Line; D002642:Chick Embryo; D016547:Kinesins / Q000378:metabolism*; D051379:Mice; D010766:Phosphorylation; D010770:Phosphotransferases / Q000378:metabolism*
D010770:Phosphotransferases; D016547:Kinesins