title: Heterodimers of the Arabidopsis transcription factors bZIP1 and bZIP53 reprogram amino acid metabolism during low energy stress.
abstract: Control of energy homeostasis is crucial for plant survival, particularly under biotic or abiotic stress conditions. Energy deprivation induces dramatic reprogramming of transcription, facilitating metabolic adjustment. An in-depth knowledge of the corresponding regulatory networks would provide opportunities for the development of biotechnological strategies. Low energy stress activates the Arabidopsis thaliana group S1 basic leucine zipper transcription factors bZIP1 and bZIP53 by transcriptional and posttranscriptional mechanisms. Gain-of-function approaches define these bZIPs as crucial transcriptional regulators in Pro, Asn, and branched-chain amino acid metabolism. Whereas chromatin immunoprecipitation analyses confirm the direct binding of bZIP1 and bZIP53 to promoters of key metabolic genes, such as ASPARAGINE SYNTHETASE1 and PROLINE DEHYDROGENASE, the G-box, C-box, or ACT motifs (ACTCAT) have been defined as regulatory cis-elements in the starvation response. bZIP1 and bZIP53 were shown to specifically heterodimerize with group C bZIPs. Although single loss-of-function mutants did not affect starvation-induced transcription, quadruple mutants of group S1 and C bZIPs displayed a significant impairment. We therefore propose that bZIP1 and bZIP53 transduce low energy signals by heterodimerization with members of the partially redundant C/S1 bZIP factor network to reprogram primary metabolism in the starvation response.
authors.affiliation: Julius-von-Sachs-Institut, Pharmazeutische Biologie, Universität Würzburg, Julius-von-Sachs-Platz 2, D-97082 Wuerzburg, Germany.
authors.forename: Katrin
authors.initials: K
authors.lastname: Dietrich
authors.forename: Fridtjof
authors.initials: F
authors.lastname: Weltmeier
authors.forename: Andrea
authors.initials: A
authors.lastname: Ehlert
authors.forename: Christoph
authors.initials: C
authors.lastname: Weiste
authors.forename: Mark
authors.initials: M
authors.lastname: Stahl
authors.forename: Klaus
authors.initials: K
authors.lastname: Harter
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Dröge-Laser
mesh_terms: D000596:Amino Acids / Q000378:metabolism*; D017360:Arabidopsis / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D050976:Basic-Leucine Zipper Transcription Factors / Q000235:genetics / Q000378:metabolism*; D003624:Darkness; D018506:Gene Expression Regulation, Plant; D009154:Mutation; D030821:Plants, Genetically Modified / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D011401:Promoter Regions, Genetic; D055503:Protein Multimerization; D011523:Protoplasts / Q000378:metabolism; D015398:Signal Transduction; D013312:Stress, Physiological; D014158:Transcription, Genetic
chemical_list: D000596:Amino Acids; D029681:Arabidopsis Proteins; D050976:Basic-Leucine Zipper Transcription Factors; C553903:bZIP1 protein, Arabidopsis; C544386:bZIP53 protein, Arabidopsis