Singh Khushwant, Zouhar Miloslav, Mazakova Jana, Rysanek Pavel
Department of Plant Protection, Faculty of Agrobiology, Food, and Natural Resources, Czech University of Life Sciences Prague, Czech Republic .
OMICS. 2014 Oct;18(10):645-57. doi: 10.1089/omi.2014.0081.
Abstract Phoma stem canker (blackleg) is a disease of world-wide importance on oilseed rape (Brassica napus) and can cause serious losses for crops globally. The disease is caused by dothideomycetous fungus, Leptosphaeria maculans, which is highly virulent/aggressive. Cyclophilins (CYPs) and FK506-binding proteins (FKBPs) are ubiquitous proteins belonging to the peptidyl-prolyl cis/trans isomerase (PPIase) family. They are collectively referred to as immunophilins (IMMs). In the present study, IMM genes, CYP and FKBP in haploid strain v23.1.3 of L. maculans genome, were identified and classified. Twelve CYPs and five FKBPs were determined in total. Domain architecture analysis revealed the presence of a conserved cyclophilin-like domain (CLD) in the case of CYPs and FKBP_C in the case of FKBPs. Interestingly, IMMs in L. maculans also subgrouped into single domain (SD) and multidomain (MD) proteins. They were primarily found to be localized in cytoplasm, nuclei, and mitochondria. Homologous and orthologous gene pairs were also determined by comparison with the model organism Saccharomyces cerevisiae. Remarkably, IMMs of L. maculans contain shorter introns in comparison to exons. Moreover, CYPs, in contrast with FKBPs, contain few exons. However, two CYPs were determined as being intronless. The expression profile of IMMs in both mycelium and infected primary leaves of B. napus demonstrated their potential role during infection. Secondary structure analysis revealed the presence of atypical eight β strands and two α helices fold architecture. Gene ontology analysis of IMMs predicted their significant role in protein folding and PPIase activity. Taken together, our findings for the first time present new prospects of this highly conserved gene family in phytopathogenic fungus.
摘要 油菜茎点霉溃疡病（黑胫病）是一种对全球油菜（甘蓝型油菜）具有重要影响的病害，可给全球农作物造成严重损失。该病由子囊菌门真菌大茎点菌引起，该菌具有高度毒性/侵袭性。亲环蛋白（CYPs）和FK506结合蛋白（FKBPs）是普遍存在的蛋白质，属于肽基脯氨酰顺/反异构酶（PPIase）家族。它们统称为亲免素（IMMs）。在本研究中，对大茎点菌基因组单倍体菌株v23.1.3中的IMM基因、CYP和FKBP进行了鉴定和分类。总共鉴定出12个CYPs和5个FKBPs。结构域分析表明，CYPs存在保守的亲环蛋白样结构域（CLD），FKBPs存在FKBP_C结构域。有趣的是，大茎点菌中的IMMs也可分为单结构域（SD）和多结构域（MD）蛋白。主要发现它们定位于细胞质、细胞核和线粒体中。还通过与模式生物酿酒酵母进行比较确定了同源和直系同源基因对。值得注意的是，与外显子相比，大茎点菌的IMMs内含子较短。此外，与FKBPs相比，CYPs的外显子较少。然而，有两个CYPs被确定为无内含子。IMMs在大茎点菌菌丝体和感染的油菜初生叶中的表达谱表明了它们在感染过程中的潜在作用。二级结构分析揭示了非典型的八条β链和两条α螺旋折叠结构。IMMs的基因本体分析预测了它们在蛋白质折叠和PPIase活性中的重要作用。综上所述，我们的研究结果首次展示了这个高度保守的基因家族在植物病原真菌中的新前景。
