Abl tyrosine kinase and its substrate Ena/VASP have functional interactions with kinesin-1.
Relatively little is known about how microtubule motors are controlled or about how the functions of different cytoskeletal systems are integrated. A yeast two-hybrid screen for proteins that bind to Drosophila Enabled (Ena), an actin polymerization factor that is negatively regulated by Abl tyrosine kinase, identified kinesin heavy chain (Khc), a member of the kinesin-1 subfamily of microtubule motors. Coimmunoprecipitation from Drosophila cytosol confirmed a physical interaction between Khc and Ena. Kinesin-1 motors can carry organelles and other macromolecular cargoes from neuronal cell bodies toward terminals in fast-axonal-transport. Ena distribution in larval axons was not affected by mutations in the Khc gene, suggesting that Ena is not itself a fast transport cargo of Drosophila kinesin-1. Genetic interaction tests showed that in a background sensitized by reduced Khc gene dosage, a reduction in Abl gene dosage caused distal paralysis and axonal swellings. A concomitant reduction in ena dosage rescued those defects. These results suggest that Ena/VASP, when not inhibited by the Abl pathway, can bind Khc and reduce its transport activity in axons.
Department of Biology, Indiana University, Bloomington, IN 47405, USA.
MaryAnn
M
Martin
Shawn M
SM
Ahern-Djamali
F Michael
FM
Hoffmann
William M
WM
Saxton
D000818:Animals; D001369:Axons / Q000378:metabolism; D015815:Cell Adhesion Molecules / Q000378:metabolism / Q000502:physiology*; D002460:Cell Line; D004268:DNA-Binding Proteins / Q000378:metabolism* / Q000502:physiology; D029721:Drosophila Proteins / Q000378:metabolism* / Q000502:physiology; D016547:Kinesins / Q000378:metabolism* / Q000502:physiology; D008840:Microfilament Proteins / Q000378:metabolism / Q000502:physiology*; D010750:Phosphoproteins / Q000378:metabolism / Q000502:physiology*; D011505:Protein-Tyrosine Kinases / Q000378:metabolism / Q000502:physiology*; D016315:Proto-Oncogene Proteins c-abl / Q000378:metabolism*; D013379:Substrate Specificity; D000098662:Vasodilator-Stimulated Phosphoprotein
D015815:Cell Adhesion Molecules; D004268:DNA-Binding Proteins; D029721:Drosophila Proteins; C092744:ENA-VASP proteins; D008840:Microfilament Proteins; D010750:Phosphoproteins; D000098662:Vasodilator-Stimulated Phosphoprotein; C426236:ARG tyrosine kinase; D011505:Protein-Tyrosine Kinases; D016315:Proto-Oncogene Proteins c-abl; D016547:Kinesins