Targeting of Nbp1 to the inner nuclear membrane is essential for spindle pole body duplication.
EMBO J
; 30(16): 3337-52, 2011 Jul 22.
Article
en En
| MEDLINE
| ID: mdl-21785410
ABSTRACT
Spindle pole bodies (SPBs), like nuclear pore complexes, are embedded in the nuclear envelope (NE) at sites of fusion of the inner and outer nuclear membranes. A network of interacting proteins is required to insert a cytoplasmic SPB precursor into the NE. A central player of this network is Nbp1 that interacts with the conserved integral membrane protein Ndc1. Here, we establish that Nbp1 is a monotopic membrane protein that is essential for SPB insertion at the inner face of the NE. In vitro and in vivo studies identified an N-terminal amphipathic α-helix of Nbp1 as a membrane-binding element, with crucial functions in SPB duplication. The karyopherin Kap123 binds to a nuclear localization sequence next to this amphipathic α-helix and prevents unspecific tethering of Nbp1 to membranes. After transport into the nucleus, Nbp1 binds to the inner nuclear membrane. These data define the targeting pathway of a SPB component and suggest that the amphipathic α-helix of Nbp1 is important for SPB insertion into the NE from within the nucleus.
Texto completo:
1
Bases de datos:
MEDLINE
Asunto principal:
Saccharomyces cerevisiae
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Proteínas Nucleares
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Proteínas de Ciclo Celular
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Transporte Activo de Núcleo Celular
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Proteínas del Citoesqueleto
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Beta Carioferinas
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Proteínas de Saccharomyces cerevisiae
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Huso Acromático
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Membrana Nuclear
Idioma:
En
Revista:
EMBO J
Año:
2011
Tipo del documento:
Article
País de afiliación:
Alemania