The endoplasmic reticulum connects to the nucleus by constricted junctions that mature after mitosis.
EMBO Rep
; 25(7): 3137-3159, 2024 Jul.
Article
em En
| MEDLINE
| ID: mdl-38877171
ABSTRACT
Junctions between the endoplasmic reticulum (ER) and the outer membrane of the nuclear envelope (NE) physically connect both organelles. These ER-NE junctions are essential for supplying the NE with lipids and proteins synthesized in the ER. However, little is known about the structure of these ER-NE junctions. Here, we systematically study the ultrastructure of ER-NE junctions in cryo-fixed mammalian cells staged in anaphase, telophase, and interphase by correlating live cell imaging with three-dimensional electron microscopy. Our results show that ER-NE junctions in interphase cells have a pronounced hourglass shape with a constricted neck of 7-20 nm width. This morphology is significantly distinct from that of junctions within the ER network, and their morphology emerges as early as telophase. The highly constricted ER-NE junctions are seen in several mammalian cell types, but not in budding yeast. We speculate that the unique and highly constricted ER-NE junctions are regulated via novel mechanisms that contribute to ER-to-NE lipid and protein traffic in higher eukaryotes.
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Texto completo:
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Base de dados:
MEDLINE
Assunto principal:
Retículo Endoplasmático
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Mitose
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Membrana Nuclear
Limite:
Animals
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Humans
Idioma:
En
Ano de publicação:
2024
Tipo de documento:
Article