CLONING OF A NEW KINESIN-RELATED GENE LOCATED AT THE CENTROMERIC END OF THE HUMAN MHC REGION

We previously reported the presence of a new gene (HSET) with an unkno wn function, in the centromeric side of the class II gene region of th e human major histocompatibility complex (MHC). cDNA clones correspond ing to the HSET gene were isolated from a human testis cDNA library. A 2.4 kilobase transcript from the HSET gene was abundantly expressed i n testis, B-cell, T-cell, and ovary cell lines but was not detected in lung or stomach. Analysis of the nucleotide sequence of the HSET cDNA clones revealed significant similarity to kinesin-related proteins in yeast, Drosophila, and human. Its predicted amino acid sequence conta ins a domain with strong sequence similarity to the ATP-binding and mo tor domains of a plus end-directed microtuble motor protein, kinesin, which might be involved in mitotic chromosome segregation, suggesting that the HSET gene encodes a novel kinesin-related protein.