AtHMGB15 belongs to a group of ARID-HMG proteins which are plant specific. The presence of two known DNA binding domains: AT rich interacting domain (ARID) and High Mobility Group (HMG)-box, in one polypeptide, makes this protein intriguing. Although proteins containing individual HMG and ARID domains have been characterized, not much is known about the role of ARID-HMG proteins. Promoter analysis of AtHMGB15 showed the presence of various stress responsive cis regulatory elements along with MADS-box containing transcription factors. Our result shows that the expression of AtHMGB15 increased significantly upon application of cold stress. Using ChIP-chip approach, we have identified 6128 and 4689 significantly enriched loci having AtHMGB15 occupancy under control and cold stressed condition respectively. GO analysis shows genes belonging to abiotic stress response, cold response and root development were AtHMGB15 targets during cold stress. DNA binding and footprinting assays further identified A(A/C)--ATA---(A/T)(A/T) as AtHMGB15 binding motif. The enriched probe distribution in both control and cold condition shows a bias of AtHMGB15 binding towards the transcribed (gene body) region. Further, the expression of cold stress responsive genes decreased in athmgb15 knockout plants compared to wild-type. Taken together, binding enrichment of AtHMGB15 to the promoter and upstream to stress loci suggest an unexplored role of the protein in stress induced transcription regulation.

AtHMGB15属于一组植物特有的ARID-HMG蛋白。一个多肽中存在两个已知的DNA结合结构域：AT富集相互作用域（ARID）和高迁移率组（HMG）-box，使这种蛋白质很吸引人。尽管已表征了包含单个HMG和ARID结构域的蛋白质，但对ARID-HMG蛋白质的作用知之甚少。AtHMGB15的启动子分析表明，存在多种应激反应顺式调控元件以及包含转录因子的MADS-box。我们的结果表明，在施加冷胁迫后，AtHMGB15的表达显着增加。使用ChIP芯片方法，我们已经确定在控制和冷胁迫条件下分别具有AtHMGB15占用的6128和4689个显着富集的基因座。GO分析显示，属于非生物胁迫应答，冷应答和根发育的基因是冷胁迫期间AtHMGB15的靶标。DNA结合和足迹分析进一步确定了A（A / C）-ATA ---（A / T）（A / T）为AtHMGB15结合基序。在对照和寒冷条件下富集的探针分布显示AtHMGB15结合偏向转录的（基因体）区域。此外，athmgb15中冷应激反应基因的表达下降淘汰型植物与野生型相比。两者合计，AtHMGB15绑定丰富的启动子和上游的应激基因位点表明该蛋白在应激诱导的转录调控中的未开发的作用。