Understanding the functions of kinesin-II

Species ranging from Chlamydomonas to humans possess the heterotrimeric kin esin-II holoenzyme composed of two different motor subunits and one non-mot or accessory subunit. An important function of kinesin-II is that it transp orts the components needed for the construction and maintenance of cilia an d flagella from the site of synthesis in the cell body to the site of growt h at the distal tip. Recent work suggests that kinesin-II does not directly interact with these components, but rather via a large protein complex, wh ich has been termed a raft (intraflagellar transport (IFT)). While ciliary transport is the best-established function for kinesin-II, evidence has bee n reported for possible roles in neuronal transport, melanosome transport, the secretory pathway and during mitosis. (C) 2000 Elsevier Science B.V. Al l rights reserved.