Endoplasmic reticulum stress activates the expression of a sub-group of protein disulfide isomerase genes and AtbZIP60 modulates the response in Arabidopsis thaliana
Endoplasmic reticulum stress activates the expression of a sub-group of protein disulfide isomerase genes and AtbZIP60 modulates the response in Arabidopsis thaliana
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DOI：
10.1007/s00438-008-0356-z
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发表时间：
2008-09-01
影响因子：
3.1
通讯作者：
Christopher, David A.
中科院分区：
文献类型：
--
作者：
Lu, Dong-Ping;Christopher, David A.
进入真核细胞分泌途径的蛋白质在内质网（ER）中折叠成其天然结构。蛋白质折叠的破坏导致ER应激并激活信号级联，称为未折叠蛋白质反应（UPR），其恢复折叠能力。在哺乳动物和酵母中，蛋白质二硫键异构酶（PDI）是在UPR期间活化的关键蛋白质折叠催化剂。然而，很少有人知道的PDI基因的响应在植物中的UPR。在拟南芥中，我们确定了12个PDI基因，不同的多肽长度，存在的信号肽和ER保留信号，硫氧还蛋白和跨膜结构域的数量和位置。AtPDI基因的表达进行了研究，在不同的组织中，在化学诱导的UPR，并在无效突变体的UPR信号介质（AtIRE 1 -2和AtbZIP 60）。6个AtPDI基因的表达被UPR显著上调，并被转录抑制剂放线菌素D显著减弱，表明UPR诱导AtPDI基因转录。在暴露于UPR的Atire 1 -2突变体中，AtPDI和BIP 2（结合蛋白）基因表达不受影响，然而，在Atbzip 60突变体中，四个AtPDI基因的表达下降。我们提出，额外的UPR信号传导因子补充AtbZIP 60在ER胁迫期间在植物中激活AtPDI基因表达。
Proteins entering the secretory pathway of eukaryotic cells are folded into their native structures in the endoplasmic reticulum (ER). Disruption of protein folding causes ER stress and activates signaling cascades, designated the unfolded protein response (UPR), that restore folding capacity. In mammals and yeast, the protein disulfide isomerases (PDIs) are key protein folding catalysts activated during UPR. However, little is known about the response of PDI genes to UPR in plants. In Arabidopsis thaliana, we identified 12 PDI genes that differed in polypeptide length, presence of signal peptide and ER retention signal, and the number and positions of thioredoxin and transmembrane domains. AtPDI gene expression was investigated in different tissues, in response to chemically induced UPR, and in null mutants of UPR signaling mediators (AtIRE1-2 and AtbZIP60). The expression of six AtPDI genes was significantly up-regulated by UPR and sharply attenuated by the transcription inhibitor, actinomycin D, indicating UPR induced AtPDI gene transcription. AtPDI and BIP2 (Binding protein) gene expression was not affected in the Atire1-2 mutant exposed to UPR, however, the expression of four AtPDI genes was decreased in the Atbzip60 mutant. We proposed that additional UPR signaling factors complement AtbZIP60 in the activation of AtPDI gene expression during ER stress in plants.