Efficient protein targeting to the inner nuclear membrane requires atlastin-dependent maintenance of ER topology
- ETH Zurich, Switzerland
Abstract
Newly synthesized membrane proteins are targeted to the inner nuclear membrane (INM) by diffusion within the membrane system of the endoplasmic reticulum (ER), translocation through nuclear pore complexes (NPCs) and retention on nuclear partners. Using a visual in vitro assay we previously showed that efficient protein targeting to the INM depends on nucleotide hydrolysis. We now reveal that INM targeting is GTP-dependent. Exploiting in vitro reconstitution and in vivo analysis of INM targeting, we establish that Atlastins, membrane-bound GTPases of the ER, sustain the efficient targeting of proteins to the INM by their continued activity in preserving ER topology. When ER topology is altered, the long-range diffusional exchange of proteins in the ER network and targeting efficiency to the INM are diminished. Highlighting the general importance of proper ER topology, we show that Atlastins also influence NPC biogenesis and timely exit of secretory cargo from the ER.
Article and author information
Author details
Funding
H2020 European Research Council (ERC Advanced Grant NucEnv)
- Sumit Pawar
- Ulrike Kutay
The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.
Copyright
© 2017, Pawar et al.
This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.
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Efficient protein targeting to the inner nuclear membrane requires atlastin-dependent maintenance of ER topology
eLife 6:e28202.
https://doi.org/10.7554/eLife.28202
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