All kinesin superfamily protein, KIF, genes in mouse and human

Intracellular transport is essential for morphogenesis and functioning of t he cell. The kinesin superfamily proteins (KIFs) have been shown to transpo rt membranous organelles and protein complexes in a microtubule- and ATP-de pendent manner. More than 30 KIFs have been reported in mice. However, the nomenclature of KIFs has not been clearly established, resulting in various designations and redundant names for a single KIF. Here, we report the ide ntification and classification of all KIFs in mouse and human genome transc ripts. Previously unidentified murine KIFs were found by a PCR-based search . The identification of all KIFs was confirmed by a database search of the total human genome. As a result, there are a total of 45 KIFs. The nomencla ture of all KIFs is presented. To understand the function of KIFs in intrac ellular transport in a single tissue, we focused on the brain. The expressi on of 38 KIFs was detected in brain tissue by Northern blotting or PCR usin g cDNA. The brain, mainly composed of highly differentiated and polarized c ells such as neurons and glia, requires a highly complex intracellular tran sport system as indicated by the increased number of KIFs for their sophist icated functions. It is becoming increasingly clear that the cell uses a nu mber of KIFs and tightly controls the direction, destination, and velocity of transportation of various important functional molecules, including mRNA . This report will set the foundation of KIF and intracellular transport re search.