Figure 3.

The complemented myoA⁻/B⁻ cells express normal levels of the wild-type and mutant myoB heavy chain. Western blot analysis of total cell lysates was used to determine the expression level of the myoB heavy chain in wild-type, null, and reexpression strains. The position of the M_r 116,000 marker is indicated on the left of the Western blot. The levels of expression of the 125-kDa myoB heavy chain in equal numbers of Ax3 control cells (Ax3), myoA⁻/B⁻ double mutants (A⁻/B⁻), and double mutants expressing full-length myoB (myoB), myoB/SH3⁻ (myoB/SH3⁻), and the myoB serine to alanine mutant (myoB-S332A) are shown. The levels of myoB expression are indicated below each lane, and the values are expressed relative to the Ax3 strain (which is set to 1). Note that the myoB Ab recognizes the endogenous myoB, as well as the smaller truncated myoB in the myoB/SH3⁻ cells, and the mutant form of myoB in the myoB-S332A cells.