4mbe | pdb_00004mbe
Sac3:Sus1:Cdc31:Nup1 complex
Structural highlights
FunctionCDC31_YEAST Functions as a component of the nuclear pore complex (NPC) and the spindle pole body (SPB) half-bridge. At the SPB, it is recruited by KAR1 and MPS3 to the SPB half-bridge and involved in the initial steps of SPB duplication. It probably plays a similar role in de novo assembly of NPCs at the nuclear envelope. Also involved in connection with the protein kinase KIC1 in the maintenance of cell morphology and integrity.[1] [2] [3] [4] [5] [6] Publication Abstract from PubMedThe conserved Sac3:Thp1:Sem1:Sus1:Cdc31 (TREX2) complex binds to nuclear pore complexes (NPCs) and, in addition to integrating mRNA nuclear export with preceding steps in the gene expression pathway, facilitates re-positioning of highly regulated actively transcribing genes (such as GAL1) to NPCs. Although TREX2 is thought to bind NPC protein Nup1, defining the precise role of this interaction has been frustrated by the complex pleiotropic phenotype exhibited by nup1Delta strains. To provide a structural framework for understanding the binding of TREX2 to NPCs and its function in the gene expression pathway, we have determined the structure of the Nup1:TREX2 interaction interface and used this information to engineer a Sac3 variant that impairs NPC binding while not compromising TREX2 assembly. This variant inhibited the NPC association of both de-repressed and activated GAL1 and also produced mRNA export and growth defects. These results indicate that the TREX2:Nup1 interaction facilitates the efficient nuclear export of bulk mRNA together with the re-positioning of GAL1 to NPCs that is required for transcriptional control that is mediated by removal of SUMO from repressors by NPC-bound Ulp1. Structural basis for binding the TREX2 complex to nuclear pores, GAL1 localisation and mRNA export.,Jani D, Valkov E, Stewart M Nucleic Acids Res. 2014 Apr 4. PMID:24705649[7] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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