IDENTIFICATION AND CLASSIFICATION OF 16 NEW KINESIN SUPERFAMILY (KIF)PROTEINS IN MOUSE GENOME

KIF (kinesin superfamily) proteins are microtubule-dependent molecular motors that play important roles in intracellular transport and cell division. The extent to which KIFs are involved in various transportin g phenomena, as well as their regulation mechanism, are unknown. The i dentification of 16 new KIFs in this report doubles the existing numbe r of KIFs known in the mouse. Conserved nucleotide sequences in the mo tor domain were amplified by PCR using cDNAs of mouse nervous tissue, kidney, and small intestine as templates. The new KIFs were studied wi th respect to their expression patterns in different tissues, chromoso mal location, and molecular evolution. Our results suggest that (i) th ere is no apparent tendency among related subclasses of KIFs of cosegr egation in chromosomal mapping, and (ii) according to their tissue dis tribution patterns, KIFs can be divided into two classes-i.e., ubiquit ous and specific tissue-dominant. Further characterization of KIFs may elucidate unknown fundamental phenomena underlying intracellular tran sport. Finally, we propose a straightforward nomenclature system for t he members of the mouse kinesin superfamily.