Visualizing the disordered nuclear transport machinery in situ.
Nature
; 617(7959): 162-169, 2023 05.
Article
en En
| MEDLINE
| ID: mdl-37100914
ABSTRACT
The approximately 120 MDa mammalian nuclear pore complex (NPC) acts as a gatekeeper for the transport between the nucleus and cytosol1. The central channel of the NPC is filled with hundreds of intrinsically disordered proteins (IDPs) called FG-nucleoporins (FG-NUPs)2,3. Although the structure of the NPC scaffold has been resolved in remarkable detail, the actual transport machinery built up by FG-NUPs-about 50 MDa-is depicted as an approximately 60-nm hole in even highly resolved tomograms and/or structures computed with artificial intelligence4-11. Here we directly probed conformations of the vital FG-NUP98 inside NPCs in live cells and in permeabilized cells with an intact transport machinery by using a synthetic biology-enabled site-specific small-molecule labelling approach paired with highly time-resolved fluorescence microscopy. Single permeabilized cell measurements of the distance distribution of FG-NUP98 segments combined with coarse-grained molecular simulations of the NPC allowed us to map the uncharted molecular environment inside the nanosized transport channel. We determined that the channel provides-in the terminology of the Flory polymer theory12-a 'good solvent' environment. This enables the FG domain to adopt expanded conformations and thus control transport between the nucleus and cytoplasm. With more than 30% of the proteome being formed from IDPs, our study opens a window into resolving disorder-function relationships of IDPs in situ, which are important in various processes, such as cellular signalling, phase separation, ageing and viral entry.
Texto completo:
1
Bases de datos:
MEDLINE
Asunto principal:
Núcleo Celular
/
Transporte Activo de Núcleo Celular
/
Proteínas de Complejo Poro Nuclear
/
Proteínas Intrínsecamente Desordenadas
Límite:
Animals
Idioma:
En
Revista:
Nature
Año:
2023
Tipo del documento:
Article
País de afiliación:
Alemania