Rice kinesin O12 is identical to kinesin OsKCH1

Abstract

Since 2004, we have been conducting molecularlevel in vitro studies for the biochemical characterization of kinesins encoded on the rice genome. Some kinesins have previously been characterized, and their biochemical and crystallographic studies have been published (1–4). The kinesin we named as ‘O12’ is one of the several rice kinesins. To express kinesin O12 using an Escherichia coli expression system, we used a plasmid (accession number: AK065586; clone name: J013034O12) that was supplied by the National Institute of Agrobiological Science. We determined the unique enzymatic properties of kinesin O12 in 2005 and reported its biochemical characterization at meetings in 2006 (5, 6) and 2007 (7). At that stage, O12 was recognized as a novel kinesin. We believe that we characterized the biochemical properties of the rice kinesin O12 before any other research groups. Subsequently, we published an article detailing additional biochemical studies of kinesin O12 in The Journal of Biochemistry in 2011 (8). The aim of this study was to apply the unique characteristics of rice plant kinesins to the field of bionanotechnology. For instance, we observed an interesting property that the ATPase activity of the motor domain of kinesin O12, which does not contain a calponin homology domain, is regulated by actin and may be applicable in the regulation of a molecular shuttle based on the kinesin motor protein. As mentioned so far, our series of studies on the rice kinesins have been performed independently, on the basis of our original ideas since 2004.