This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. An understanding of how the nuclear pore complex (NPC) mediates nucleocytoplasmic exchange requires a comprehensive inventory of the molecular components of the NPC and a knowledge of how each component contributes to the overall structure of this large molecular translocation machine. Therefore, we have taken a comprehensive approach to classify all components of the yeast NPC (nucleoporins). This involved identifying all the proteins present in a highly enriched NPC fraction, determining which of these proteins were nucleoporins, and localizing each nucleoporin within the NPC. Using these data, we present a map of the molecular architecture of the yeast NPC and provide evidence for a Brownian affinity gating mechanism for nucleocytoplasmic transport. This work has been published (M.P. Rout, J.D. Aitchison, A. Suprapto, K. Hjertaas, Y-M. Zhao, B.T. Chait, J. Cell. Biol. 148 (2000) 635-651)and M.P. Rout, J.D. Aitchison, M.O. Magnasco, B.T. Chait, Trends Cell Biology 13(2003)622-628. We are currently testing our model for nuclear transport using three different approaches: in vivo measurements of transport kinetics;production of an artificial NPC;and physics-based modeling of the gating/transport processes. All materials enter or exit the cell nucleus through nuclear pore complexes (NPCs), efficient transport devices that combine high selectivity and throughput. NPC-associated proteins containing phenylalanine?glycine repeats (FG nups) have large, flexible, unstructured proteinaceous regions, and line the NPC. A central feature of NPC-mediated transport is the binding of cargo-carrying soluble transport factors to the unstructured regions of FG nups. Here, we model the dynamics of nucleocytoplasmic transport as diffusion in an effective potential resulting from the interaction of the transport factors with the flexible FG nups, using a minimal number of assumptions consistent with the most well-established structural and functional properties of NPC transport. We discuss how specific binding of transport factors to the FG nups facilitates transport, and how this binding and competition between transport factors and other macromolecules for binding sites and space inside the NPC accounts for the high selectivity of transport. We also account for why transport is relatively insensitive to changes in the number and distribution of FG nups in the NPC, providing an explanation for recent experiments where up to half the total mass of the FG nups has been deleted without abolishing transport. Our results suggest strategies for the creation of artificial nanomolecular sorting devices. A manuscript describing this work has been submitted for publication.
| Manning, Lois R; Popowicz, Anthony M; Padovan, Julio C et al. (2017) Gel filtration of dilute human embryonic hemoglobins reveals basis for their increased oxygen binding. Anal Biochem 519:38-41 |
| Boice, Michael; Salloum, Darin; Mourcin, Frederic et al. (2016) Loss of the HVEM Tumor Suppressor in Lymphoma and Restoration by Modified CAR-T Cells. Cell 167:405-418.e13 |
| Chait, Brian T; Cadene, Martine; Olinares, Paul Dominic et al. (2016) Revealing Higher Order Protein Structure Using Mass Spectrometry. J Am Soc Mass Spectrom 27:952-65 |
| Krutchinsky, Andrew N; Padovan, Júlio C; Cohen, Herbert et al. (2015) Maximizing ion transmission from atmospheric pressure into the vacuum of mass spectrometers with a novel electrospray interface. J Am Soc Mass Spectrom 26:649-58 |
| Mast, Fred D; Rachubinski, Richard A; Aitchison, John D (2015) Signaling dynamics and peroxisomes. Curr Opin Cell Biol 35:131-6 |
| Krutchinsky, Andrew N; Padovan, Júlio C; Cohen, Herbert et al. (2015) Optimizing electrospray interfaces using slowly diverging conical duct (ConDuct) electrodes. J Am Soc Mass Spectrom 26:659-67 |
| Oricchio, Elisa; Papapetrou, Eirini P; Lafaille, Fabien et al. (2014) A cell engineering strategy to enhance the safety of stem cell therapies. Cell Rep 8:1677-1685 |
| Zhong, Yu; Morris, Deanna H; Jin, Lin et al. (2014) Nrbf2 protein suppresses autophagy by modulating Atg14L protein-containing Beclin 1-Vps34 complex architecture and reducing intracellular phosphatidylinositol-3 phosphate levels. J Biol Chem 289:26021-37 |
| Indiani, Chiara; O'Donnell, Mike (2013) A proposal: Source of single strand DNA that elicits the SOS response. Front Biosci (Landmark Ed) 18:312-23 |
| Di Virgilio, Michela; Callen, Elsa; Yamane, Arito et al. (2013) Rif1 prevents resection of DNA breaks and promotes immunoglobulin class switching. Science 339:711-5 |
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