Regulation of Nuclear Pore and Nuclear Envelope Disassembly at Mitosis

When a higher eukaryotic cell divides, nuclei undergo dramatic remodeling (Prunuske and Ullman, 2006). In most cases, the nuclear envelope is disassembled. This breakdown process involves dispersal of the nuclear membrane as well as solubilization of nuclear pore complexes, which break into small subunits. Our laboratory is interested in elucidating how the nuclear envelope gets remodeled during each cell cycle. We have discovered an early role for the nucleoporins Nup153 and Nup358/RanBP2 in recruiting the COPI complex to the nuclear envelope (Liu et al., 2003, Prunuske et al., 2006). This coatomer complex has been previously characterized in the context of vesicular traffic at the Golgi apparatus. We are currently trying to understand the role of COPI at the nuclear envelope in greater mechanistic detail and are focused on questions such as what other proteins are involved in recruiting COPI members and how the local recruitment of COPI contributes to nuclear membrane dispersal. With new insight into players involved in nuclear disassembly, we are also interested in learning how the signaling cascades that occur as a cell progresses into mitosis regulate this step.