Microtubule-associated force-producing protein that plays a role in organelle transport. Its motor activity is directed toward the microtubule's plus end (By similarity). Cooperates with dynein in organizing spindle assembly during cell division. During the developmental stage. Composed of three structural domains: a large globular N-terminal domain which is responsible for the motor activity of kinesin (it hydrolyzes ATP and binds microtubule), a central alpha-helical coiled coil domain that mediates the heavy chain dimerization; and a small globular C-terminal domain which interacts with other proteins, vesicles and membranous organelles. Significantly impairs the rate of cell growth and, when combined with a previously characterized dynein inhibition, results in dramatic defects in mitotic spindle assembly. Belongs to the TRAFAC class myosin-kinesin ATPase superfamily. Kinesin family. The cDNA sequence misses the fragment coding for residues 1006 to 1042 localized between two repeated sequences and probably lost during cloning.