The nucleoporin Nup50 activates the Ran guanine nucleotide exchange factor RCC1 to promote NPC assembly at the end of mitosis.

Autor: Holzer G; Institute of Biochemistry and Molecular Cell Biology, Medical School, RWTH Aachen University, Aachen, Germany., De Magistris P; Institute of Biochemistry and Molecular Cell Biology, Medical School, RWTH Aachen University, Aachen, Germany.; Friedrich Miescher Laboratory of the Max Planck Society, Tübingen, Germany., Gramminger C; Friedrich Miescher Laboratory of the Max Planck Society, Tübingen, Germany., Sachdev R; Friedrich Miescher Laboratory of the Max Planck Society, Tübingen, Germany., Magalska A; Friedrich Miescher Laboratory of the Max Planck Society, Tübingen, Germany., Schooley A; Friedrich Miescher Laboratory of the Max Planck Society, Tübingen, Germany., Scheufen A; Institute of Biochemistry and Molecular Cell Biology, Medical School, RWTH Aachen University, Aachen, Germany., Lennartz B; Institute of Biochemistry and Molecular Cell Biology, Medical School, RWTH Aachen University, Aachen, Germany., Tatarek-Nossol M; Institute of Biochemistry and Molecular Cell Biology, Medical School, RWTH Aachen University, Aachen, Germany., Lue H; Institute of Biochemistry and Molecular Cell Biology, Medical School, RWTH Aachen University, Aachen, Germany., Linder MI; Institute of Biochemistry, ETH Zurich, Zurich, Switzerland., Kutay U; Institute of Biochemistry, ETH Zurich, Zurich, Switzerland., Preisinger C; Proteomics Facility, Interdisciplinary Centre for Clinical Research (IZKF), Medical School, RWTH Aachen University, Aachen, Germany., Moreno-Andres D; Institute of Biochemistry and Molecular Cell Biology, Medical School, RWTH Aachen University, Aachen, Germany., Antonin W; Institute of Biochemistry and Molecular Cell Biology, Medical School, RWTH Aachen University, Aachen, Germany.
Jazyk: angličtina
Zdroj: The EMBO journal [EMBO J] 2021 Dec 01; Vol. 40 (23), pp. e108788. Date of Electronic Publication: 2021 Nov 02.
DOI: 10.15252/embj.2021108788
Abstrakt: During mitotic exit, thousands of nuclear pore complexes (NPCs) assemble concomitant with the nuclear envelope to build a transport-competent nucleus. Here, we show that Nup50 plays a crucial role in NPC assembly independent of its well-established function in nuclear transport. RNAi-mediated downregulation in cells or immunodepletion of Nup50 protein in Xenopus egg extracts interferes with NPC assembly. We define a conserved central region of 46 residues in Nup50 that is crucial for Nup153 and MEL28/ELYS binding, and for NPC interaction. Surprisingly, neither NPC interaction nor binding of Nup50 to importin α/β, the GTPase Ran, or chromatin is crucial for its function in the assembly process. Instead, an N-terminal fragment of Nup50 can stimulate the Ran GTPase guanine nucleotide exchange factor RCC1 and NPC assembly, indicating that Nup50 acts via the Ran system in NPC reformation at the end of mitosis. In support of this conclusion, Nup50 mutants defective in RCC1 binding and stimulation cannot replace the wild-type protein in in vitro NPC assembly assays, whereas excess RCC1 can compensate the loss of Nup50.
(© 2021 The Authors. Published under the terms of the CC BY NC ND 4.0 license.)
Databáze: MEDLINE
Externí odkaz: