Uncovering nuclear pore complexity with innovation

Abstract

Advances in imaging and reductionist approaches have provided a high-resolution understanding of nuclear pore complex structure and transport, revealing unexpected mechanistic complexities based on nucleoporin functions and specialized import and export pathways.

Figure 1. NPC structure and transport

A. Early EM image of the NPC cytoplasmic face in a salamander oocyte NE. Reprinted with permission from Gall, 1954. Scale bar, 100nm. B. 8-fold symmetry of the NPC in the NE plane resolved by dSTORM microscopy. Lumenal domain of the transmembrane Nup gp210 (magenta) and the FG Nups (green) in a Xenopus laevis oocyte NE. Reprinted with permission from Löschberger, et al, 2012. Scale bar, 100nm. C. Schematic of NPC architecture. Measurements indicate dimensions for the human NPC from cryoET (Maimon et al., 2012). D. Transport pathways through the NPC, with distinct FG Nup requirements for karyopherin transport versus mRNA export (Terry and Wente, 2009). Protein transport occurs in ~10ms (Yang and Musser, 2006), whereas mRNA export takes 180ms (Grünwald and Singer, 2010). Transport cargo sizes are to scale with NPC: protein cargo as ~80kDa globular shape, and mRNP size potentially proportional to the transcript length (including the 5′ Cap-binding protein complex (CBP) (star) and other RNA binding proteins (circles).