Current research in our group focuses on the vertebrate nuclear pore complex (NPC). The main biological questions we are investigating are:

(1) How is this supramolecular machine assembled and integrated into the double membranes surrounding the nucleus; (2) The mechanism for targeting and translocation through the NPC of large cellular cargoes and viruses. To study these topics we rely on the cell-free nuclear reconstitution system, derived from frog egg extracts and on genetic manipulation of mammalian cells.



From: Harel & Gruenbaum, Cell, 2011.


The main source of biological material for our experiments are unfertilized frog eggs, shown on the right.

These eggs are used to produce fractionated cell-free extracts, which allow us to assemble functional nuclei in the test-tube. The nuclei can be directly visualized by fluorescent, confocal or electron microscopy.

One example is shown below.




Direct immunofluorescent staining of NPCs on the surface of a reconstituted nucleus. Staining by an affinity-purified antibody directed against the pore-membrane protein POM121. See more about the functional roles of this protein in Shaulov et al., J. Cell Science, 2011


A major research goal in this field of cell biology is to deduce a step-by-step molecular mechanism for the entire process of NPC biogenesis and to place NPC and nuclear envelope assembly in the wider context of cell-cycle progression. For a global view of the mechanistic questions driving this field of research, see: Wandke and Kutay, Cell 152, 1222-5, 2013.

Other projects in the lab involve the targeting of intact proteasome particles to the nuclear compartment, the impact of heat-shock and stress on nuclear transport, the viral-host interactions of Herpes Simplex Virus 1 (HSV1) and a rare genetic disease affecting a nuclear pore component in humans.