Cytoplasmic dynein is a motor protein complex that is essential in a number of processes including chromosome segregation during mitosis, movement of vesicular cargo, positioning of intracellular organelles, and the establishment of cell polarity in oocyte development. This project focuses on characterizing the role of dynein light chain LC8 from Drosophila in dynein assembly and cargo recognition. LC8 is highly conserved, with 94% sequence identity between Drosophila and human. The dynein intermediate chain IC74 mediates the interaction between the heavy and light chains, and the assembly of LC8 and IC74 is likely to be a key step in formation of a functional complex. To elucidate the basis for LC8/IC74 recognition, the structure of the complex will be determined using NMR spectroscopy. The swallow protein, Swa, an example of cargo, is an RNA binding protein, which is essential in establishing cell polarity in developing oocytes. The interaction of Swa with LC8 has been demonstrated in Drosophila. Identification of binding sites in this interaction will be determined by limited proteolysis and cross-linking studies.
Broader Impact: Structural studies of LC8 and its interactions with IC74 and Swa will be a significant contribution to understanding both the assembly of the dynein motor complex and its attachment to cargo. This work will entail substantive contributions from a number of undergraduates. The project will also involve development of a class on the current topics in structural biology and biophysics, which have become central to much of biological research.
