A checkpoint function for Nup98 in nuclear pore formation suggested by novel inhibitory nanobodies.
EMBO J
; 43(11): 2198-2232, 2024 Jun.
Article
em En
| MEDLINE
| ID: mdl-38649536
ABSTRACT
Nuclear pore complex (NPC) biogenesis is a still enigmatic example of protein self-assembly. We now introduce several cross-reacting anti-Nup nanobodies for imaging intact nuclear pore complexes from frog to human. We also report a simplified assay that directly tracks postmitotic NPC assembly with added fluorophore-labeled anti-Nup nanobodies. During interphase, NPCs are inserted into a pre-existing nuclear envelope. Monitoring this process is challenging because newly assembled NPCs are indistinguishable from pre-existing ones. We overcame this problem by inserting Xenopus-derived NPCs into human nuclear envelopes and using frog-specific anti-Nup nanobodies for detection. We further asked whether anti-Nup nanobodies could serve as NPC assembly inhibitors. Using a selection strategy against conserved epitopes, we obtained anti-Nup93, Nup98, and Nup155 nanobodies that block Nup-Nup interfaces and arrest NPC assembly. We solved structures of nanobody-target complexes and identified roles for the Nup93 α-solenoid domain in recruiting Nup358 and the Nup214·88·62 complex, as well as for Nup155 and the Nup98 autoproteolytic domain in NPC scaffold assembly. The latter suggests a checkpoint linking pore formation to the assembly of the Nup98-dominated permeability barrier.
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MEDLINE
Assunto principal:
Poro Nuclear
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Complexo de Proteínas Formadoras de Poros Nucleares
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Anticorpos de Domínio Único
Limite:
Animals
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Humans
Idioma:
En
Ano de publicação:
2024
Tipo de documento:
Article