The endoplasmic reticulum connects to the nucleus by constricted junctions that mature after mitosis.
EMBO Rep
; 25(7): 3137-3159, 2024 Jul.
Article
in 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.
Key words
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Endoplasmic Reticulum
/
Mitosis
/
Nuclear Envelope
Limits:
Animals
/
Humans
Language:
En
Journal:
EMBO Rep
Journal subject:
BIOLOGIA MOLECULAR
Year:
2024
Document type:
Article
Affiliation country:
Austria