Transmembrane domain length is responsible for the ability of a plant reticulon to shape endoplasmic reticulum tubules in vivo
Article first published online: 9 SEP 2010
© 2010 The Authors. Journal compilation © 2010 Blackwell Publishing Ltd
The Plant Journal
Volume 64, Issue 3, pages 411–418, November 2010
How to Cite
Tolley, N., Sparkes, I., Craddock, C. P., Eastmond, P. J., Runions, J., Hawes, C. and Frigerio, L. (2010), Transmembrane domain length is responsible for the ability of a plant reticulon to shape endoplasmic reticulum tubules in vivo. The Plant Journal, 64: 411–418. doi: 10.1111/j.1365-313X.2010.04337.x
- Issue published online: 26 OCT 2010
- Article first published online: 9 SEP 2010
- Accepted manuscript online: 13 AUG 2010 10:35AM EST
- Received 29 June 2010; accepted 9 August 2010; published online 8 September 2010.
- endoplasmic reticulum;
- organelle shape;
Reticulons are integral endoplasmic reticulum (ER) membrane proteins that have the ability to shape the ER into tubules. It has been hypothesized that their unusually long conserved hydrophobic regions cause reticulons to assume a wedge-like topology that induces membrane curvature. Here we provide proof of this hypothesis. When over-expressed, an Arabidopsis thaliana reticulon (RTNLB13) localized to, and induced constrictions in, cortical ER tubules. Ectopic expression of RTNLB13 was sufficient to induce ER tubulation in an Arabidopsis mutant (pah1 pah2) whose ER membrane is mostly present in a sheet-like form. By sequential shortening of the four transmembrane domains (TMDs) of RTNLB13, we show that the length of the transmembrane regions is directly correlated with the ability of RTNLB13 to induce membrane tubulation and to form low-mobility complexes within the ER membrane. We also show that full-length TMDs are necessary for the ability of RTNLB13 to reside in the ER membrane.