Mechanisms determining the morphology of the peripheral ER.
Cell
; 143(5): 774-88, 2010 Nov 24.
Article
em En
| MEDLINE
| ID: mdl-21111237
ABSTRACT
The endoplasmic reticulum (ER) consists of the nuclear envelope and a peripheral network of tubules and membrane sheets. The tubules are shaped by the curvature-stabilizing proteins reticulons and DP1/Yop1p, but how the sheets are formed is unclear. Here, we identify several sheet-enriched membrane proteins in the mammalian ER, including proteins that translocate and modify newly synthesized polypeptides, as well as coiled-coil membrane proteins that are highly upregulated in cells with proliferated ER sheets, all of which are localized by membrane-bound polysomes. These results indicate that sheets and tubules correspond to rough and smooth ER, respectively. One of the coiled-coil proteins, Climp63, serves as a "luminal ER spacer" and forms sheets when overexpressed. More universally, however, sheet formation appears to involve the reticulons and DP1/Yop1p, which localize to sheet edges and whose abundance determines the ratio of sheets to tubules. These proteins may generate sheets by stabilizing the high curvature of edges.
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Retículo Endoplasmático
Limite:
Animals
Idioma:
En
Ano de publicação:
2010
Tipo de documento:
Article