Modification of ran GTPase-activating protein by the small ubiquitin-related modifier SUMO-1 requires Ubc9, an E2-type ubiquitin-conjugating enzyme homologue

• Verfasst von: Lee, Gene W. [VerfasserIn]
• Verfasst von: Melchior, Frauke [VerfasserIn]
• Verfasst von: Matunis, Michael J. [VerfasserIn]
• Verfasst von: Mahajan, Rohit [VerfasserIn]
• Verfasst von: Tian, Qingsheng [VerfasserIn]
• Verfasst von: Anderson, Paul [VerfasserIn]
• Titel: Modification of ran GTPase-activating protein by the small ubiquitin-related modifier SUMO-1 requires Ubc9, an E2-type ubiquitin-conjugating enzyme homologue
• Verf.angabe: Gene W. Lee, Frauke Melchior, Michael J. Matunis, Rohit Mahajan, Qingsheng Tian, and Paul Anderson
• E-Jahr: 1998
• Jahr: 13 March 1998
• Umfang: 5 S.
• Fussnoten: Gesehen am 06.09.2023
• Titel Quelle: Enthalten in: The journal of biological chemistry
• Ort Quelle: Bethesda, Md. : ASBMB Publications, 1905
• Jahr Quelle: 1998
• Band/Heft Quelle: 273(1998), 11, Seite 6503-6507
• ISSN Quelle: 1083-351X
• DOI: doi:10.1074/jbc.273.11.6503
• Datenträger: Online-Ressource
• Sprache: eng
• K10plus-PPN: 185890515X

Abstract

Covalent modification of the Ran GTPase-activating protein RanGAP1 with the ubiquitin-related protein SUMO-1 promotes its association with Nup358, a component of the cytoplasmic fibrils emanating from the nuclear pore complex (1, 2). in Xenopus egg extracts, Nup358 can be found in a complex with Ubc9 (3), a structural homologue of the E2-type ubiquitin-conjugating enzymes (UBCs). Here we show that a subset of the human homologue of Ubc9 (HsUbc9) colocalizes with RanGAP1 at the nuclear envelope. HsUbc9 forms thiolester conjugates with recombinant SUMO-1, but not with recombinant ubiquitin, indicating that it is functionally distinct from E2-type UBCs. Finally, HsUbc9 is required for the modification of RanGAP1 by SUMO-1. These results suggest that HsUbc9 is a component of a novel enzymatic cascade that modifies RanGAP1, and possibly other substrates, with SUMO-1.