Entry into the nuclear pore complex is controlled by a cytoplasmic exclusion zone containing dynamic GLFG-repeat nucleoporin domains.
J Cell Sci
; 127(Pt 1): 124-36, 2014 Jan 01.
Article
em En
| MEDLINE
| ID: mdl-24144701
ABSTRACT
Nuclear pore complexes (NPCs) mediate nucleocytoplasmic movement. The central channel contains proteins with phenylalanine-glycine (FG) repeats, or variations (GLFG, glycine-leucine-phenylalanine-glycine). These are 'intrinsically disordered' and often represent weak interaction sites that become ordered upon interaction. We investigated this possibility during nuclear transport. Using electron microscopy of S. cerevisiae, we show that NPC cytoplasmic filaments form a dome-shaped structure enclosing GLFG domains. GLFG domains extend out of this structure and are part of an 'exclusion zone' that might act as a partial barrier to entry of transport-inert proteins. The anchor domain of a GLFG nucleoporin locates exclusively to the central channel. By contrast, the localisation of the GLFG domains varied between NPCs and could be cytoplasmic, central or nucleoplasmic and could stretch up to 80 nm. These results suggest a dynamic exchange between ordered and disordered states. In contrast to diffusion through the NPC, transport cargoes passed through the exclusion zone and accumulated near the central plane. We also show that movement of cargo through the NPC is accompanied by relocation of GLFG domains, suggesting that binding, restructuring and movement of these domains could be part of the translocation mechanism.
Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Idioma:
En
Ano de publicação:
2014
Tipo de documento:
Article