Here, we combine super-resolution fluorescence localization microscopy with scanning electron microscopy to map the position of proteins of nuclear pore complexes in isolated Xenopus laevis oocyte nuclear envelopes with molecular resolution in both imaging modes. We use the periodic molecular structure of the nuclear pore complex to superimpose direct stochastic optical reconstruction microscop...

Previtellogenic, stage-1 Xenopus oocytes produce mainly 5S and tRNA, whereas vitellogenic oocytes, stages 2-6, synthesize predominantly 18S and 28S rRNA. Using nucleoplasmin-coated gold as a transport substrate, it was determined that the shift in synthesis from small to large RNAs during oogenesis is accompanied by an increase in both the rates of signal-mediated nuclear import and the functio...

To understand the structure and function of large molecular machines, accurate knowledge of their stoichiometry is essential. In this study, we developed an integrated targeted proteomics and super-resolution microscopy approach to determine the absolute stoichiometry of the human nuclear pore complex (NPC), possibly the largest eukaryotic protein complex. We show that the human NPC has a previ...

Nucleoporin Nup154 is a Drosophila component of the nuclear pore complex (NPC), evolutionarily conserved from yeast to humans. While functional studies carried out in both yeast and metazoan cells indicated that Nup154 homologs are key elements of the NPC framework, the striking phenotypic specificity displayed by nup154 hypomorphic mutant alleles suggested that Nup154 might play additional rol...

An evolutionary advantage of intrinsically disordered proteins (IDPs) is their ability to bind a variety of folded proteins-a paradigm that is central to the nucleocytoplasmic transport mechanism, in which nuclear transport receptors mediate the translocation of various cargo through the nuclear pore complex by binding disordered phenylalanine-glycine-rich nucleoporins (FG-Nups). FG-Nups are hi...

The nuclear pore complex is the primary conduit for nuclear import and export of molecules. In this issue, Gu et al. uncover a novel mechanism in which immune signaling and programmed cell death require nuclear pore rearrangement and release of sequestered cyclin-dependent kinase inhibitors to elicit immunity and death.

Nuclear structures similar to those of the nuclear pore complex were found on chromosomes. This finding indicates that part of the pore complex is retained by the chromosomes through mitosis in the absence of the nuclear membrane. The formation of approximately the same number of pore complexes in the presence and absence of protein synthesis during the first 4 h after mitosis proves the reasse...

Nucleocytoplasmic transport has been the subject of a large body of research in the past few decades. Recently, the focus of investigations in this field has shifted from studies of the overall function of the nuclear pore complex (NPC) to the examination of the role of different domains of phenylalanine-glycine nucleoporin (FG Nup) sequences on the NPC function. In our recent bioinformatics st...

The nuclear pore complex (NPC) controls the transport of macromolecules between the nucleus and cytoplasm, but its molecular architecture has thus far remained poorly defined. We biochemically reconstituted NPC core protomers and elucidated the underlying protein-protein interaction network. Flexible linker sequences, rather than interactions between the structured core scaffold nucleoporins, m...