IMMUNOLOGICAL DETECTION OF ACTIN IN THE 14S CILIARY DYNEIN OF TETRAHYMENA

The association of actin with Tetrahymena ciliary dyneins was examined using a polyclonal antibody against Tetrahymena actin. Western blotti ng shows that actin is present in the 148 dynein fraction, but not in the 22S dynein fraction, which comprises the outer arm. By anion-excha nge chromatography, 14S dynein can be further separated into three maj or fractions that contain four distinct heavy chains in total. When ea ch fraction was tested by anti-actin immunoblotting, all three fractio ns contained actin in nearly stoichiometric amounts with the heavy cha in. Since Tetrahymena actin differs significantly from actins of other species, the association with inner-arm dynein may be a conserved pro perty of actin.