Langland J O, Jin S, Jacobs B L, Roth D A
Department of Plant, Soil and Insect Sciences, University of Wyoming, Laramie 82071-3354, USA.
Plant Physiol. 1995 Jul;108(3):1259-67. doi: 10.1104/pp.108.3.1259.
Plant virus or viroid infection stimulates the phosphorylation of a plant-encoded protein of M(r) 68,000 to 70,000 (now termed pPKR) that is associated with double-stranded RNA-stimulated protein kinase activity. Using various biochemical and immunological comparisons, we have demonstrated that this plant protein is an analog of the mammalian PKR enzymes. pPKR is both cytosolic and ribosome associated, similar to mammalian PKR, and appears to be capable of phosphorylating exogenous histones. Monoclonal anti-serum to the human PKR as well as antiserum to a conserved double-stranded RNA-binding domain present on mammalian PKR demonstrated cross-reactivity with pPKR. Likewise, polyclonal antiserum to the pPKR detected the mouse and human PKR in western blot analysis. Northern blot analysis of a mammalian PKR cDNA detected a specific 2.5-kb transcript present in plant poly (A)+ RNA.
植物病毒或类病毒感染会刺激一种分子量为68,000至70,000的植物编码蛋白（现称为pPKR）发生磷酸化，该蛋白与双链RNA刺激的蛋白激酶活性相关。通过各种生化和免疫学比较，我们已经证明这种植物蛋白是哺乳动物PKR酶的类似物。pPKR既存在于细胞质中，也与核糖体相关，类似于哺乳动物的PKR，并且似乎能够磷酸化外源性组蛋白。针对人PKR的单克隆抗血清以及针对哺乳动物PKR上保守的双链RNA结合结构域的抗血清都显示与pPKR有交叉反应。同样，针对pPKR的多克隆抗血清在蛋白质印迹分析中检测到了小鼠和人PKR。对哺乳动物PKR cDNA的Northern印迹分析检测到植物聚腺苷酸加尾RNA中存在一种特定的2.5kb转录本。
