Evaluating the Dynein Heavy Chain Gene Family in Tetrahymena

In this chapter, we describe our methods to evaluate the dynein heavy chain genes expressed in a cell. Dynein is the high molecular weight molecular motor that produces directed movement along microtubules. All known dyneins travel to the proximal or minus end of the microtubule. The large dynein complex (M_r 1200–2000K) is comprised of several different polypeptides. The smaller subunits mediate the attachment of the dynein to its cargo and regulate dynein activity. The heavy chains (M_r >500K) contain the motor activity. Each heavy chain folds into a short flexible tail, which associates with other subunits and with the cargo, and a compact globular head, which transduces the chemical energy derived from ATP hydrolysis into mechanical motion.