title: The JAZ proteins: a crucial interface in the jasmonate signaling cascade.
abstract: Jasmonates are phytohormones that regulate many aspects of plant growth, development, and defense. Within the signaling cascades that are triggered by jasmonates, the JASMONATE-ZIM DOMAIN (JAZ) repressor proteins play a central role. The endogenous bioactive JA-Ile conjugate mediates the binding of JAZ proteins to the F-box protein CORONATINE INSENSITIVE1 (COI1), part of the Skp1/Cullin/F-box SCF(COI1) ubiquitin E3 ligase complex. Upon the subsequent destruction of the JAZ proteins by the 26S proteasome, multiple transcription factors are relieved from JAZ-mediated repression, allowing them to activate their respective downstream responses. However, many questions remain regarding the targets, specificity, function, and regulation of the different JAZ proteins. Here, we review recent studies on the model plant Arabidopsis thaliana that provided essential and novel insights. JAZ proteins have been demonstrated to interact with a broad array of transcription factors that each control specific downstream processes. Recruitment of the corepressor TOPLESS unveiled a mechanism for JAZ-mediated gene repression. Finally, the presence of JAZ proteins was also found to be regulated by alternative splicing and interactions with proteins from other hormonal signaling pathways. Overall, these contemporary findings underscore the value of protein-protein interaction studies to acquire fundamental insight into molecular signaling pathways.
authors.affiliation: Department of Plant Systems Biology, VIB, B-9052 Ghent, Belgium.
authors.forename: Laurens
authors.initials: L
authors.lastname: Pauwels
authors.forename: Alain
authors.initials: A
authors.lastname: Goossens
mesh_terms: D017398:Alternative Splicing; D000872:Anthocyanins / Q000096:biosynthesis; D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism; D051778:Basic Helix-Loop-Helix Leucine Zipper Transcription Factors / Q000378:metabolism; D003517:Cyclopentanes / Q000378:metabolism*; D018506:Gene Expression Regulation, Plant; D007295:Inositol Phosphates / Q000378:metabolism; D054883:Oxylipins / Q000378:metabolism*; D010937:Plant Growth Regulators / Q000378:metabolism*; D051479:Plant Infertility; D011485:Protein Binding; D012097:Repressor Proteins / Q000235:genetics / Q000378:metabolism*; D015398:Signal Transduction
chemical_list: D000872:Anthocyanins; D029681:Arabidopsis Proteins; D051778:Basic Helix-Loop-Helix Leucine Zipper Transcription Factors; C112279:COI1 protein, Arabidopsis; D003517:Cyclopentanes; D007295:Inositol Phosphates; D054883:Oxylipins; D010937:Plant Growth Regulators; D012097:Repressor Proteins; C013571:inositol pentaphosphate; C011006:jasmonic acid