THE CHLAMYDOMONAS KINESIN-LIKE PROTEIN FLA10 IS INVOLVED IN MOTILITY ASSOCIATED WITH THE FLAGELLAR MEMBRANE

The Chlamydomonas FLA10 gene was shown to encode a flagellar kinesin-l ike protein (Walther, Z., M. Vashishtha, and J. L. Hall. 1994. J. Cell Biol. 126:175-185). By using a temperature-sensitive allele of FLA10, we have determined that the FLA10 protein is necessary for both the b idirectional movement of polystyrene beads on the flagellar membrane a nd intraflagellar transport (IFT), the bidirectional movement of granu le-like particles beneath the flagellar membrane (Kozminski, K. G., K. A, Johnson, P. Forscher, and J. L. Rosenbaum. 1993. Proc. Natl. Acad. Sci. (USA). 90:5519-5523), In addition, we have correlated the presen ce and position of the IFT particles visualized by light microscopy wi th that of the electron dense complexes (rafts) observed beneath the f lagellar membrane by electron microscopy. A role for FLA10 in submembr anous or flagellar surface motility is also strongly supported by the immunolocalization of FLA10 to the region between the axonemal outer d oubler microtubules and the flagellar membrane.