Cooperation of the ER-shaping proteins atlastin, lunapark, and reticulons to generate a tubular membrane network
In higher eukaryotes, the endoplasmic reticulum (ER) contains a network of membrane tubules, which transitions into sheets during mitosis. Network formation involves curvature-stabilizing proteins, including the reticulons (Rtns), as well as the membrane-fusing GTPase atlastin (ATL) and the lunapark...
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doaj-a9a1309b38d449e9b1d13b7eb048e1632021-05-05T00:34:39ZengeLife Sciences Publications LtdeLife2050-084X2016-09-01510.7554/eLife.18605Cooperation of the ER-shaping proteins atlastin, lunapark, and reticulons to generate a tubular membrane networkSongyu Wang0Hanna Tukachinsky1Fabian B Romano2Tom A Rapoport3https://orcid.org/0000-0001-9911-4216Howard Hughes Medical Institute, Harvard Medical School, Boston, United States; Department of Cell Biology, Harvard Medical School, Boston, United StatesHoward Hughes Medical Institute, Harvard Medical School, Boston, United States; Department of Cell Biology, Harvard Medical School, Boston, United StatesHoward Hughes Medical Institute, Harvard Medical School, Boston, United States; Department of Cell Biology, Harvard Medical School, Boston, United StatesHoward Hughes Medical Institute, Harvard Medical School, Boston, United States; Department of Cell Biology, Harvard Medical School, Boston, United StatesIn higher eukaryotes, the endoplasmic reticulum (ER) contains a network of membrane tubules, which transitions into sheets during mitosis. Network formation involves curvature-stabilizing proteins, including the reticulons (Rtns), as well as the membrane-fusing GTPase atlastin (ATL) and the lunapark protein (Lnp). Here, we have analyzed how these proteins cooperate. ATL is needed to not only form, but also maintain, the ER network. Maintenance requires a balance between ATL and Rtn, as too little ATL activity or too high Rtn4a concentrations cause ER fragmentation. Lnp only affects the abundance of three-way junctions and tubules. We suggest a model in which ATL-mediated fusion counteracts the instability of free tubule ends. ATL tethers and fuses tubules stabilized by the Rtns, and transiently sits in newly formed three-way junctions. Lnp subsequently moves into the junctional sheets and forms oligomers. Lnp is inactivated by mitotic phosphorylation, which contributes to the tubule-to-sheet conversion of the ER.https://elifesciences.org/articles/18605endoplasmic reticulumorganelle morphologymembrane structure |
collection |
DOAJ |
language |
English |
format |
Article |
sources |
DOAJ |
author |
Songyu Wang Hanna Tukachinsky Fabian B Romano Tom A Rapoport |
spellingShingle |
Songyu Wang Hanna Tukachinsky Fabian B Romano Tom A Rapoport Cooperation of the ER-shaping proteins atlastin, lunapark, and reticulons to generate a tubular membrane network eLife endoplasmic reticulum organelle morphology membrane structure |
author_facet |
Songyu Wang Hanna Tukachinsky Fabian B Romano Tom A Rapoport |
author_sort |
Songyu Wang |
title |
Cooperation of the ER-shaping proteins atlastin, lunapark, and reticulons to generate a tubular membrane network |
title_short |
Cooperation of the ER-shaping proteins atlastin, lunapark, and reticulons to generate a tubular membrane network |
title_full |
Cooperation of the ER-shaping proteins atlastin, lunapark, and reticulons to generate a tubular membrane network |
title_fullStr |
Cooperation of the ER-shaping proteins atlastin, lunapark, and reticulons to generate a tubular membrane network |
title_full_unstemmed |
Cooperation of the ER-shaping proteins atlastin, lunapark, and reticulons to generate a tubular membrane network |
title_sort |
cooperation of the er-shaping proteins atlastin, lunapark, and reticulons to generate a tubular membrane network |
publisher |
eLife Sciences Publications Ltd |
series |
eLife |
issn |
2050-084X |
publishDate |
2016-09-01 |
description |
In higher eukaryotes, the endoplasmic reticulum (ER) contains a network of membrane tubules, which transitions into sheets during mitosis. Network formation involves curvature-stabilizing proteins, including the reticulons (Rtns), as well as the membrane-fusing GTPase atlastin (ATL) and the lunapark protein (Lnp). Here, we have analyzed how these proteins cooperate. ATL is needed to not only form, but also maintain, the ER network. Maintenance requires a balance between ATL and Rtn, as too little ATL activity or too high Rtn4a concentrations cause ER fragmentation. Lnp only affects the abundance of three-way junctions and tubules. We suggest a model in which ATL-mediated fusion counteracts the instability of free tubule ends. ATL tethers and fuses tubules stabilized by the Rtns, and transiently sits in newly formed three-way junctions. Lnp subsequently moves into the junctional sheets and forms oligomers. Lnp is inactivated by mitotic phosphorylation, which contributes to the tubule-to-sheet conversion of the ER. |
topic |
endoplasmic reticulum organelle morphology membrane structure |
url |
https://elifesciences.org/articles/18605 |
work_keys_str_mv |
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