KID, A NOVEL KINESIN-LIKE DNA-BINDING PROTEIN, IS LOCALIZED TO CHROMOSOMES AND THE MITOTIC SPINDLE

Microtubule-associated motor proteins are thought to be involved in sp indle formation and chromosome movements in mitosis/meiosis. We have m olecularly cloned cDNAs for a gene that codes for a novel member of th e kinesin family of proteins, Nucleotide sequencing reveals that the p redicted gene product is a 73 kDa protein and is related to some exten t to the Drosophila nod gene product, which is involved in chromosomal segregation during meiosis, A sequence similar to the microtubule bin ding motor domain of kinesin is present in the N-terminal half of the protein, and its ability to bind to microtubules is demonstrated, Furt hermore, we show that its C-terminal half contains a putative nuclear localization signal similar to that of Jun and is able to bind to DNA, Accordingly, the protein was termed Kid (kinesin-like DNA binding pro tein), Indirect immunofluorescence studies show that Kid co-localizes with mitotic chromosomes and that it is enriched in the kinetochore at anaphase, Thus, we propose that Kid might play a role(s) in regulatin g the chromosomal movement along microtubules during mitosis.