title: Arabidopsis B-cell lymphoma2 (Bcl-2)-associated athanogene 7 (BAG7)-mediated heat tolerance requires translocation, sumoylation and binding to WRKY29.
abstract: To cope with stress and increased accumulation of misfolded proteins, plants and animals use a survival pathway known as the unfolded protein response (UPR) that signals between the endoplasmic reticulum (ER) and the nucleus to maintain cell homeostasis via proper folding of proteins. B-cell lymphoma2 (Bcl-2)-associated athanogene (BAG) proteins are an evolutionarily conserved family of co-chaperones that are linked to disease states in mammals and responses to environmental stimuli (biotic and abiotic) in plants. Molecular and physiological techniques were used to functionally characterize a newly identified branch of the UPR initiated by the ER-localized co-chaperone from Arabidopsis thaliana, AtBAG7. AtBAG7 has functional roles in both the ER and the nucleus. Upon heat stress, AtBAG7 is sumoylated, proteolytically processed and translocated from the ER to the nucleus, where interaction with the WRKY29 transcription factor occurs. Sumoylation and translocation are required for the AtBAG7-WRKY29 interaction and subsequent stress tolerance. In the ER, AtBAG7 interacts with the ER-localized transcription factor, AtbZIP28, and established UPR regulator, the AtBiP2 chaperone. The results indicate that AtBAG7 plays a central regulatory role in the heat-induced UPR pathway.
authors.affiliation: Institute for Plant Genomics and Biotechnology, Texas A&M University, College Station, TX, 77843, USA.|Department of Plant Pathology and Microbiology, Texas A&M University, College Station, TX, 77843, USA.
authors.forename: Yurong
authors.initials: Y
authors.lastname: Li
authors.affiliation: Centre for Tropical Crops and Biocommodities, Queensland University of Technology, PO Box 2434, Brisbane, 4001, Qld, Australia.
authors.forename: Brett
authors.initials: B
authors.lastname: Williams
authors.affiliation: Institute for Plant Genomics and Biotechnology, Texas A&M University, College Station, TX, 77843, USA.|Department of Plant Pathology and Microbiology, Texas A&M University, College Station, TX, 77843, USA.
authors.forename: Martin
authors.initials: M
authors.lastname: Dickman
mesh_terms: D017360:Arabidopsis / Q000235:genetics / Q000502:physiology*; D029681:Arabidopsis Proteins / Q000737:chemistry / Q000378:metabolism*; D002467:Cell Nucleus / Q000378:metabolism; D004721:Endoplasmic Reticulum / Q000378:metabolism; D059865:Endoplasmic Reticulum Stress; D018506:Gene Expression Regulation, Plant; D018869:Heat-Shock Response; D008954:Models, Biological; D011485:Protein Binding; D000072417:Protein Domains; D021381:Protein Transport; D058207:Sumoylation; D000071436:Thermotolerance; D014158:Transcription, Genetic
chemical_list: D029681:Arabidopsis Proteins
keywords: B-cell lymphoma2 (Bcl-2) -associated athanogene 7 (BAG7); WRKY29; basic leucine-zipper 28 (bZIP28); binding immunoglobulin protein (BiP); endoplasmic reticulum (ER); heat stress; sumoylation; unfolded protein response (UPR)