When
a higher eukaryotic cell divides, nuclei undergo dramatic remodeling (Prunuske & 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 mucleoporins 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.
