1 / 37

RNA transport and the nuclear pore complex

marlie
Download Presentation

RNA transport and the nuclear pore complex

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

    1. 1. The nuclear pore complex (NPC) 2. RanGTP pathway 3. Transport of mRNA RNA transport and the nuclear pore complex Florian Krapp, Seminar Molecular Machines and RNA Biology

    2. 1. The nuclear pore complex (NPC) 2. RanGTP pathway 3. Transport of mRNA nucleo-cytoplasmatic transport

    3. 1. The nuclear pore complex (NPC) 2. RanGTP pathway 3. Transport of mRNA Contents 1. The nuclear pore complex (NPC) 2. RanGTP pathway 3. Transport of mRNA

    4. 1. The nuclear pore complex (NPC) 2. RanGTP pathway 3. Transport of mRNA 1. The nuclear pore complex (NPC) nuclear pore complexes of Xenopus laevis oocyte (SFM, Uni Münster)

    5. 1. The nuclear pore complex (NPC) 2. RanGTP pathway 3. Transport of mRNA The nuclear envelope outer nuclear membrane perinuclear space inner nuclear membrane nuclear lamina ... there are 2.000 NPCs per nucleus!

    6. 1. The nuclear pore complex (NPC) 2. RanGTP pathway 3. Transport of mRNA What should an NPC be able to do? integration in the nuclear envelope outer nuclear membrane inner nuclear membrane nuclear lamina passive transduction of small molecules interaction with nuclear export/import signals selective directional transport

    7. 1. The nuclear pore complex (NPC) 2. RanGTP pathway 3. Transport of mRNA Some data on the NPC molecular mass 50 MDa (S. cerevisiae) 120 MDa (Vertebrates) (ribosome: 4 MDa) structural proteins 30 (S. cerevisiae) 50-100 (Vertebrates) size 120 nm diameter (opening ~60 nm) 200 nm deep

    8. 1. The nuclear pore complex (NPC) 2. RanGTP pathway 3. Transport of mRNA What does an NPC look like?

    9. 1. The nuclear pore complex (NPC) 2. RanGTP pathway 3. Transport of mRNA Components of the NPC

    10. 1. The nuclear pore complex (NPC) 2. RanGTP pathway 3. Transport of mRNA cross section and envelope integration

    11. 1. The nuclear pore complex (NPC) 2. RanGTP pathway 3. Transport of mRNA Nucleoporins (Nups) structural proteins the NPC is built of mostly symmetrical on cytoplasmatic and nuclear sides FG-nucleoporins containing repeats (phenylalanine and glycine)

    12. 1. The nuclear pore complex (NPC) 2. RanGTP pathway 3. Transport of mRNA Localization of Nups

    13. 1. The nuclear pore complex (NPC) 2. RanGTP pathway 3. Transport of mRNA specificity of Nups the NPC is no static structure each Nup may have specific interaction partners Nups also interact with each other

    14. 1. The nuclear pore complex (NPC) 2. RanGTP pathway 3. Transport of mRNA 2. RanGTP pathway Canis lupus familiaris Ran with bound GDP (Steward, M. et al.)

    15. 1. The nuclear pore complex (NPC) 2. RanGTP pathway 3. Transport of mRNA What is Ran? small GTPase (Ras superfamily) exists in 2 forms GTP-bound: predominantly in the nucleoplasm GDP-bound: predominantly in the cytoplasm transition mediated by 2 proteins RanGEF (Ran guanine exchange factor) in the nucleoplasm RanGAP (GTPase activating protein) in the cytoplasm

    16. 1. The nuclear pore complex (NPC) 2. RanGTP pathway 3. Transport of mRNA The Ran cycle

    17. 1. The nuclear pore complex (NPC) 2. RanGTP pathway 3. Transport of mRNA Karyopherins, NES and NLS Karyopherins (importin-ß-superfamily) Importins (e. g. importin-a and importin-ß) Exportins NES: nuclear export signal short amino acid sequence (5-6 amino acids) NLS: nuclear localization signal ... -Pro-Pro-Lys-Lys-Lys-Arg-Lys-Val-... (Simian Virus 40)

    18. 1. The nuclear pore complex (NPC) 2. RanGTP pathway 3. Transport of mRNA Ran-controlled export

    19. 1. The nuclear pore complex (NPC) 2. RanGTP pathway 3. Transport of mRNA Ran-controlled import

    20. 1. The nuclear pore complex (NPC) 2. RanGTP pathway 3. Transport of mRNA Nuclear transport: an overview

    21. 1. The nuclear pore complex (NPC) 2. RanGTP pathway 3. Transport of mRNA non-protein transport by Ran pre-miRNA Exportin-5 snRNA cap, CRM1 (Exportin-1), PHAX snRNP Importin-ß ribosomal subunits CRM1 (Exportin-1)

    22. 1. The nuclear pore complex (NPC) 2. RanGTP pathway 3. Transport of mRNA Summary Ran NES and NLS define destination of Proteins karyopherins mediate transport through the NPC the Ran cycle controls and supports protein transport necessary for transport of: pre-miRNA snRNA / snRNP ribosomal subunits tRNA Proteins

    23. 1. The nuclear pore complex (NPC) 2. RanGTP pathway 3. Transport of mRNA 3. Transport of mRNA crystal structure of S. cerevisiae Mex67:Mtr2 heterodimer (Fribourg, S. et al.)

    24. 1. The nuclear pore complex (NPC) 2. RanGTP pathway 3. Transport of mRNA Why do we need another transport system? numerous processing events must occur before export 5‘ capping 3‘ poly-A attachment splicing immature mRNA must not be delivered to cytoplasm! mRNA export is linked to transcription processing translation

    25. 1. The nuclear pore complex (NPC) 2. RanGTP pathway 3. Transport of mRNA mRNA and mRNP mRNA is not „naked“ 5‘ cap and cap binding proteins 3‘ poly-A tail and poly-A binding proteins splicing factors general RNA binding factors other factors involved in pre-mRNA processing

    26. 1. The nuclear pore complex (NPC) 2. RanGTP pathway 3. Transport of mRNA conservation of mRNP transport most of the involved proteins have orthologs... Yeast Vertebrate Mex67p NXF1/TAP Mtr2 p15 Yra1p Aly/REF Sub2p UAP56/HEL THO THO TREX TREX - EJC Dbp5p Dbp5 ... ...

    27. 1. The nuclear pore complex (NPC) 2. RanGTP pathway 3. Transport of mRNA 3 steps of mRNP transport Assembly of mRNP export complexes - quality control Translocation through NPC Disassembly of mRNP export complexes

    28. 1. The nuclear pore complex (NPC) 2. RanGTP pathway 3. Transport of mRNA Mex67p and Mtr2p Mex67p associated with NPCs capable of shuttling cargo needs heterodimerization with... Mtr2p both form a receptor heterodimer involved in 75% of all mRNA transports

    29. 1. The nuclear pore complex (NPC) 2. RanGTP pathway 3. Transport of mRNA 3 steps of mRNP transport

    30. 1. The nuclear pore complex (NPC) 2. RanGTP pathway 3. Transport of mRNA 1. mRNP assembly

    31. 1. The nuclear pore complex (NPC) 2. RanGTP pathway 3. Transport of mRNA 2. translocation: mechanism weak interactions between Nups and Mex67p:Mtr2p simple diffusion prevention of the return of mRNPs

    32. 1. The nuclear pore complex (NPC) 2. RanGTP pathway 3. Transport of mRNA 2. translocation: transfer of Dbp5

    33. 1. The nuclear pore complex (NPC) 2. RanGTP pathway 3. Transport of mRNA 2. translocation: transfer of Dbp5

    34. 1. The nuclear pore complex (NPC) 2. RanGTP pathway 3. Transport of mRNA 2. translocation: transfer of Dbp5

    35. 1. The nuclear pore complex (NPC) 2. RanGTP pathway 3. Transport of mRNA 2. translocation: transfer of Dbp5

    36. 1. The nuclear pore complex (NPC) 2. RanGTP pathway 3. Transport of mRNA 3. mRNP disassembly ...is almost done!

    37. 1. The nuclear pore complex (NPC) 2. RanGTP pathway 3. Transport of mRNA Literature and Pictures Papers and Articles Erkmann, J.A. and U. Kutay, Nuclear export of mRNA: from the site of transcription to the cytoplasm. Exp Cell Res, 2004. 296(1): p. 12-20. Cole, C.N. and J.J. Scarcelli, Transport of messenger RNA from the nucleus to the cytoplasm. Curr Opin Cell Biol, 2006. 18(3): p. 299-306. Stewart, M., Ratcheting mRNA out of the nucleus. Mol Cell, 2007. 25(3): p. 327-30. Bagley, S. et al., The nuclear pore complex. J Cell Sci, 2000. 113(22): p. 3885-3886. Beck, M. et al., Nuclear Core Complex Structure and Dynamics revealed by Cryoelectron Tomography. Science, 2004. 306(5700): p. 1387-1390. Rout, M. P. et al., The Yeast Nuclear Pore Complex: Composition, Architecture, and Transport Mechanism. The Journal of Cell Biology, 2000. 148: p. 635-651. Rout, M. P. et al., Virtual gating and nuclear transport: the hole picture TRENDS in Cell Biology, 2003. 13(12): p. 622-628. Corbett, A. et al., Hot trends erupting in the nuclear transport field. EMBO reports, 2004. 5(5): p. 453-458. Lund, E. et al, Nuclear Export of MicroRNA Precursors. Science, 2004. 303(5654): p. 95-98. Hakata, Y. et al., A Multifunctional Domain in Human CRM1 (Exportin 1) Mediates RanBP3 Binding and Multimerization of Human T-Cell Leukemia Virus Type 1 Rex Protein. Mol Cell Biol, 2003. 23(23): p. 8751-8761. Ohno, M. et al., PHAX, a mediator of U snRNA nuclear export whose activity is regulated by phosphorylation. Cell, 2000. 101(2): p. 187-198. Internet sources http://celldynamics.uni-muenster.de/Projects/ProA6Img/A6figure1.jpg http://www.unige.ch/sciences/biologie/bicel/stutz/research.html http://www.ncbi.nlm.nih.gov/Structure/index.shtml http://wikipedia.org/ http://electron.mit.edu/~gsteele/mirrors/elchem.kaist.ac.kr/jhkwak/TopometrixWeb/images/nucpor.jpg

    38. 1. The nuclear pore complex (NPC) 2. RanGTP pathway 3. Transport of mRNA Thank you for listening!

More Related