Assembly of nuclear pore complexes
Nuclear pore complexes assemble and integrate in the two membranes at the end of mitosis but also during interphase. This is a stepwise process in which the individual nucleoporins and larger subcomplexes interact and in which the link to the chromatin and the nuclear membranes is established in an ordered and well co-ordinated fashion. We dissect the individual steps, the specific nucleoporins involved and how they act as well as the underlying regulation using minimal biochemical systems, cell free assays and tissue culture experiments.
Nuclear membrane recruitment to chromatin
At the beginning of mitosis the nuclear envelope detaches from the underlying chromatin and its membranes are absorbed into the endoplasmic reticulum. Thus, nuclear envelope reformation at the end of mitosis requires the segregation of nuclear envelope specific membrane domains from the endoplasmic reticulum by establishing nuclear membrane interactions with the decondensing chromatin. We define the underlying molecular mechanisms of these processes and characterize the changes required for these both on the membranes and the chromatin.
Chromatin decondensation at the end of mitosis
Similar to the nuclear envelope, the chromatin undergoes dramatic structural changes during the cell cycle: It massively condenses at the beginning of mitosis and decondenses so that the interphase structure of the nucleus is re-established following mitotic exit. Little is known about the factors that mediate and regulate chromatin decondensation and the molecular events involved.
We have developed a cell free assay that recapitulates chromatin decondensation in vitro. Using this assay, we characterize the steps involved in chromatin decondensation, the cellular factors involved and how it is regulated and co-ordinated with other events at the end of mitosis such as nuclear envelope and pore complex reformation.