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Transmembrane domain length is responsible for the ability of a plant reticulon to shape endoplasmic reticulum tubules in vivo
Author(s) -
Tolley Nicholas,
Sparkes Imogen,
Craddock Christian P.,
Eastmond Peter J.,
Runions John,
Hawes Chris,
Frigerio Lorenzo
Publication year - 2010
Publication title -
the plant journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.058
H-Index - 269
eISSN - 1365-313X
pISSN - 0960-7412
DOI - 10.1111/j.1365-313x.2010.04337.x
Subject(s) - endoplasmic reticulum , transmembrane protein , membrane curvature , transmembrane domain , stim1 , microbiology and biotechnology , membrane contact site , biology , membrane , membrane protein , integral membrane protein , membrane topology , biophysics , biochemistry , lipid bilayer , receptor
Summary 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.