2ot8
From Proteopedia
Karyopherin Beta2/Transportin-hnRNPM NLS Complex
Structural highlights
Function[TNPO1_HUMAN] Functions in nuclear protein import as nuclear transport receptor. Serves as receptor for nuclear localization signals (NLS) in cargo substrates. Is thought to mediate docking of the importin/substrate complex to the nuclear pore complex (NPC) through binding to nucleoporin and the complex is subsequently translocated through the pore by an energy requiring, Ran-dependent mechanism. At the nucleoplasmic side of the NPC, Ran binds to the importin, the importin/substrate complex dissociates and importin is re-exported from the nucleus to the cytoplasm where GTP hydrolysis releases Ran. The directionality of nuclear import is thought to be conferred by an asymmetric distribution of the GTP- and GDP-bound forms of Ran between the cytoplasm and nucleus (By similarity). Involved in nuclear import of M9-containing proteins. In vitro, binds directly to the M9 region of the heterogeneous nuclear ribonucleoproteins (hnRNP), A1 and A2 and mediates their nuclear import. Appears also to be involved in hnRNP A1/A2 nuclear export. Mediates the nuclear import of ribosomal proteins RPL23A, RPS7 and RPL5. Binds to a beta-like import receptor binding (BIB) domain of RPL23A. In vitro, mediates nuclear import of H2A, H2B, H3 and H4 histones, and SRP19. In case of HIV-1 infection, binds and mediates the nuclear import of HIV-1 Rev. Mediates nuclear import of ADAR/ADAR1 (isoform 5) in a RanGTP-dependent manner.[1] [2] [3] [4] [HNRPM_HUMAN] Pre-mRNA binding protein in vivo, binds avidly to poly(G) and poly(U) RNA homopolymers in vitro. Involved in splicing. Acts as a receptor for carcinoembryonic antigen in Kupffer cells, may initiate a series of signaling events leading to tyrosine phosphorylation of proteins and induction of IL-1 alpha, IL-6, IL-10 and tumor necrosis factor alpha cytokines. Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedKapbeta2 (also called transportin) recognizes PY nuclear localization signal (NLS), a new class of NLS with a R/H/Kx((2-5))PY motif. Here we show that Kapbeta2 complexes containing hydrophobic and basic PY-NLSs, as classified by the composition of an additional N-terminal motif, converge in structure only at consensus motifs, which explains ligand diversity. On the basis of these data and complementary biochemical analyses, we designed a Kapbeta2-specific nuclear import inhibitor, M9M. Structure-based design of a pathway-specific nuclear import inhibitor.,Cansizoglu AE, Lee BJ, Zhang ZC, Fontoura BM, Chook YM Nat Struct Mol Biol. 2007 May;14(5):452-4. Epub 2007 Apr 15. PMID:17435768[5] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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