Open AccessTobacco mosaic virus infection induces severe morphological changes of the endoplasmic reticulum
Author(s) -
Christoph Reichel,
Roger N. Beachy
Publication year - 1998
Publication title -
proceedings of the national academy of sciences of the united states of america
Language(s) - English
Resource type - Journals
eISSN - 1091-6490
pISSN - 0027-8424
DOI - 10.1073/pnas.95.19.11169
Subject(s) - endoplasmic reticulum , plasmodesma , endomembrane system , tobacco mosaic virus , green fluorescent protein , nicotiana benthamiana , movement protein , microbiology and biotechnology , biology , er retention , intracellular , tobamovirus , cytosol , virus , virology , biochemistry , rna , golgi apparatus , cytoplasm , gene , coat protein , enzyme , mutant
The tobacco mosaic virus (TMV) movement protein (MP) facilitates transport of virus infection between adjacent cells by modifying plasmodesmata. Previous studies suggested that the cytoskeleton and the endomembrane system are involved in this transport. We examined the effects of TMV infection on the endoplasmic reticulum (ER) in transgenicNicotiana benthamiana that accumulate the green fluorescent protein (GFP) in the ER. Fluorescence microscopy was used to show that early in infection the ER undergoes dramatic morphological changes that include the conversion of tubular ER into large aggregates that revert to tubular ER in later stages of infection. These changes parallel MP accumulation and degradation. Furthermore, a fusion protein comprising MP fused to GFP accumulates in or on these large aggregates of ER. Expression of MP-GFP in the absence of virus infection led to the production of fluorescent aggregates of the same apparent form and size. Microsomes isolated from infected leaves contain MP. We show that the MP appears to behave as an integral ER membrane protein and is exposed on the cytosolic face of the ER. The importance of the association of MP with ER and its possible role in intracellular and intercellular spread of infection is discussed.