Affinity purification and subcellular localization of kinesin in human neutrophils

Studies of granule-microtubule interactions in human neutrophils have suggested that mechanochemical ATPases such as kinesin or dynein may play a role in granule mobilization during neutrophil activation by inflammatory signals. In this study we show that proteins extracted from the surface of neutrophil granules, found previously to contain microtubule-dependent ATPase activity, caused microtubules polymerized from phosphocellulose-purified rat brain tubulin to move across glass slides. Antibodies were generated against peptides based on two regions of the amino acid sequence of Drosophila kinesin: the ATPase active site (amino acids 86-99) in the head of the kinesin heavy chain and the tail of the heavy chain (residues 913-933). These antibodies were found to recognize kinesin in rat brain extracts as well as kinesin-like polypeptides in extracts of human neutrophils. Furthermore, when used in immunoaffinity chromatography, these antibodies permitted the isolation of a protein from neutrophil granule extracts that was recognized by Drosophila kinesin antibodies. Subcellular localization by immunofluorescence microscopy showed this protein to be associated principally with the cytoplasmic granules of neutrophils.