AnD AssoCIAtIon stAtesThe regulatory or cargo-binding subunits are located at the base of the intact dynein molecule and include two 74 kDa intermediate chain subunits, several 50-60 kDa light intermediate chain subunits, and three 10-14 kDa light chain subunits. We focus in this chapter on the intermediate and light chain subunits from Drosophila melanogaster and advances that have been made over the past decade in elucidating their structure, interactions, and regulation.