Histone chaperone ASF1 is involved in gene transcription activation in response to heat stress in Arabidopsis thaliana.
Histone chaperone ASF1 is involved in gene transcription activation in response to heat stress in Arabidopsis thaliana.
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DOI：
10.1111/pce.12299
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发表时间：
2014-09
期刊：
影响因子：
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通讯作者：
Minjie Weng;Yue Yang;Haiyang Feng;Zongde Pan;W. Shen;Yan Zhu;A. Dong
中科院分区：
文献类型：
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作者：
Minjie Weng;Yue Yang;Haiyang Feng;Zongde Pan;W. Shen;Yan Zhu;A. Dong
抗沉默功能1（ASF 1）是一种进化上保守的组蛋白伴侣，参与真核生物中多种基于染色质的过程。然而，它在转录中的作用和潜在的分子机制在很大程度上仍然难以捉摸，特别是在植物中。在这里，我们表明，拟南芥ASF 1同源基因，AtASF 1A和AtASF 1B，参与基因转录激活响应热胁迫。A tasf 1ab突变体显示有缺陷的基础以及获得的耐热性表型。与野生型相比，Atasf 1ab中热诱导的几个关键基因的表达，包括热休克蛋白（HSP）基因Hsp 101、Hsp 70、Hsa 32、Hsp 17. 6A和Hsp 17. 6 B-CI，以及热休克因子（HSF）基因HsfA 2，但不是HsfB 1，显著受损。我们发现AtASF 1A/B蛋白被募集到染色质上，并且它们的富集与核小体去除和RNA聚合酶II在HsfA 2和Hsa 32的启动子和编码区的积累相关，但与HsfB 1无关。此外，AtASF 1 A/B促进H3 K56乙酰化（H3 K56 ac），其与HsfA 2和Hsa 32活化相关。综上所述，我们的研究揭示了AtASF 1A/B在植物热胁迫反应中的重要功能，并表明AtASF 1A/B通过核小体去除和H3 K56 ac刺激参与了部分而非全部HSF和HSP基因的转录激活。
ANTI-SILENCING FUNCTION 1 (ASF1) is an evolutionarily conserved histone chaperone involved in diverse chromatin-based processes in eukaryotes. Yet, its role in transcription and the underlying molecular mechanisms remain largely elusive, particularly in plants. Here, we show that the A rabidopsis thaliana ASF1 homologous genes, AtASF1A and AtASF1B, are involved in gene transcription activation in response to heat stress. The A tasf1ab mutant displays defective basal as well as acquired thermotolerance phenotypes. Heat-induced expression of several key genes, including the HEAT SHOCK PROTEIN (HSP) genes Hsp101, Hsp70, Hsa32, Hsp17.6A and Hsp17.6B-CI, and the HEAT SHOCK FACTOR (HSF) gene HsfA2 but not HsfB1 is drastically impaired in Atasf1ab as compared with that in wild type. We found that AtASF1A/B proteins are recruited onto chromatin, and their enrichment is correlated with nucleosome removal and RNA polymerase II accumulation at the promoter and coding regions of HsfA2 and Hsa32 but not HsfB1. Moreover, AtASF1A/B facilitate H3K56 acetylation (H3K56ac), which is associated with HsfA2 and Hsa32 activation. Taken together, our study unravels an important function of AtASF1A/B in plant heat stress response and suggests that AtASF1A/B participate in transcription activation of some but not all HSF and HSP genes via nucleosome removal and H3K56ac stimulation.