Genomic analysis of the unfolded protein response in Arabidopsis shows its connection to important cellular processes.
We analyzed the breadth of the unfolded protein response (UPR) in Arabidopsis using gene expression analysis with Affymetrix GeneChips. With tunicamycin and DTT as endoplasmic reticulum (ER) stress-inducing agents, we identified sets of UPR genes that were induced or repressed by both stresses. The proteins encoded by most of the upregulated genes function as part of the secretory system and comprise chaperones, vesicle transport proteins, and ER-associated degradation proteins. Most of the downregulated genes encode extracellular proteins. Therefore, the UPR may constitute a triple effort by the cell: to improve protein folding and transport, to degrade unwanted proteins, and to allow fewer secretory proteins to enter the ER. No single consensus response element was found in the promoters of the 53 UPR upregulated genes, but half of the genes contained response elements also found in mammalian UPR regulated genes. These elements are enriched from 4.5- to 15-fold in this upregulated gene set.
Martínez
Immaculada M
IM
Division of Biological Sciences, University of California San Diego, La Jolla, California 92093-0116, USA.
Chrispeels
Maarten J
MJ
D017360:Arabidopsis / Q000235:genetics* / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D001483:Base Sequence; D022162:Cytoplasmic Vesicles / Q000378:metabolism; D018744:DNA, Plant / Q000737:chemistry / Q000235:genetics; D004229:Dithiothreitol / Q000494:pharmacology; D004721:Endoplasmic Reticulum / Q000187:drug effects / Q000378:metabolism; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D023281:Genomics / Q000379:methods*; D018832:Molecular Chaperones / Q000378:metabolism; D011401:Promoter Regions, Genetic / Q000235:genetics; D011487:Protein Conformation; D017510:Protein Folding; D020218:Response Elements / Q000235:genetics; D017422:Sequence Analysis, DNA; D014415:Tunicamycin / Q000494:pharmacology
D029681:Arabidopsis Proteins; D018744:DNA, Plant; D018832:Molecular Chaperones; D014415:Tunicamycin; D004229:Dithiothreitol