Department of Energy Plant Research Laboratory, Michigan State University, East Lansing, MI, USA.
Plant Signal Behav. 2010 Feb;5(2):151-3. doi: 10.4161/psb.5.2.10412. Epub 2010 Feb 23.
Plant peroxisomes are essential organelles that house diverse metabolic activities. To understand the full spectrum of peroxisomal functions, we recently performed a proteomic analysis of Arabidopsis leaf peroxisomes followed by in vivo subcellular targeting validation of some novel proteins. Here, we continue with the targeting analysis and demonstrate that the nonapeptide RVxHF, which is present near the N terminus of the newly identified peroxisomal protein, HIT3 (histidine triad family protein 3), is a functional peroxisome targeting signal type 2 (PTS2). In addition, we have confirmed the peroxisomal localization of UP6 (unknown protein 6) and GLX1 (glyoxalase 1 homolog), two proteins with possible roles in stress responses and glutathione-dependent detoxification, respectively. These data, together with results from our previous analysis of the peroxisomal proteome, reinforce the notion that peroxisomes are involved in various stress responses and suggest glutathione as a major antioxidant in plant peroxisomes.
植物过氧化物酶体是具有多种代谢活性的重要细胞器。为了全面了解过氧化物酶体的功能，我们最近对拟南芥叶片过氧化物酶体进行了蛋白质组学分析，并对一些新发现的蛋白质进行了体内亚细胞定位验证。在这里，我们继续进行靶向分析，证明存在于新鉴定的过氧化物酶体蛋白 HIT3（组氨酸三联体家族蛋白 3）N 端附近的九肽 RVxHF 是一种功能性过氧化物酶体靶向信号 2（PTS2）。此外，我们还证实了 UP6（未知蛋白 6）和 GLX1（甘油醛酶 1 同源物）的过氧化物酶体定位，这两种蛋白分别具有在应激反应和谷胱甘肽依赖的解毒中起作用的可能。这些数据与我们之前过氧化物酶体蛋白质组分析的结果一起，强化了过氧化物酶体参与各种应激反应的观点，并表明谷胱甘肽是植物过氧化物酶体中的主要抗氧化剂。
