Redistribution of membrane proteins between the Golgi apparatus and endoplasmic reticulum in plants is reversible and not dependent on cytoskeletal networks

• Published in: The Plant journal : for cell and molecular biology Vol. 29; no. 5; pp. 661 - 678
• Main Authors: Saint‐Jore, Claude M., Evins, Janet, Batoko, Henri, Brandizzi, Federica, Moore, Ian, Hawes, Chris
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Science Ltd 01.03.2002; Blackwell Science
• Subjects: Animals; Biological and medical sciences; Biological Transport - drug effects; brefeldin A; Brefeldin A - pharmacology; Cell biochemistry; Cell Line; Cell physiology; Cells, Cultured; Cycloheximide - pharmacology; cytoskeleton; Cytoskeleton - metabolism; endoplasmic reticulum; Endoplasmic Reticulum - metabolism; Fundamental and applied biological sciences. Psychology; Gene Expression - drug effects; Golgi apparatus; Golgi Apparatus - metabolism; green fluorescent protein; Green Fluorescent Proteins; Humans; Luminescent Proteins - drug effects; Luminescent Proteins - genetics; Luminescent Proteins - metabolism; Membrane Proteins - metabolism; Microscopy, Confocal; Nicotiana - cytology; Nicotiana - metabolism; Plant Epidermis - cytology; Plant Epidermis - metabolism; Plant Leaves - cytology; Plant Leaves - metabolism; Plant physiology and development; Plants, Genetically Modified; rab1 GTP-Binding Proteins - genetics; rab1 GTP-Binding Proteins - metabolism; Rats; Recombinant Fusion Proteins - drug effects; Recombinant Fusion Proteins - genetics; Recombinant Fusion Proteins - metabolism; Rhizobium - genetics; Membrane protein; Biological transport; Genetic variant; Biomembrane; Golgi apparatus; Arabidopsis thaliana; Regulation(control); Spatial distribution; Cruciferae; Actin; Dicotyledones; Angiospermae; Green fluorescent protein; Cytoskeleton; Spermatophyta; Transgenic plant; Intraspecific comparison; Microtubule; Mutation; Experimental plant; Endoplasmic reticulum
• ISSN: 0960-7412; 1365-313X
• DOI: 10.1046/j.0960-7412.2002.01252.x

Summary We have fused the signal anchor sequences of a rat sialyl transferase and a human galactosyl transferase along with the Arabidopsis homologue of the yeast HDEL receptor (AtERD2) to the jellyfish green fluorescent protein (GFP) and transiently expressed the chimeric genes in tobacco leaves. All constructs targeted the Golgi apparatus and co‐expression with DsRed fusions along with immunolabelling of stably transformed BY2 cells indicated that the fusion proteins located all Golgi stacks. Exposure of tissue to brefeldin A (BFA) resulted in the reversible redistribution of ST‐GFP into the endoplasmic reticulum. This effect occurred in the presence of a protein synthesis inhibitor and also in the absence of microtubules or actin filaments. Likewise, reformation of Golgi stacks on removal of BFA was not dependent on either protein synthesis or the cytoskeleton. These data suggest that ER to Golgi transport in the cell types observed does not require cytoskeletal‐based mechanochemical motor systems. However, expression of an inhibitory mutant of Arabidopsis Rab 1b (AtRab1b(N121I) significantly slowed down the recovery of Golgi fluorescence in BFA treated cells indicating a role for Rab1 in regulating ER to Golgi anterograde transport.