Harada Ryo, Hirakawa Yoshihisa, Yabuki Akinori, Kashiyama Yuichiro, Maruyama Moe, Onuma Ryo, Soukal Petr, Miyagishima Shinya, Hampl Vladimír, Tanifuji Goro, Inagaki Yuji
Graduate School of Life and Environmental Sciences, University of Tsukuba, Tsukuba 305-8572, Japan.
Faculty of Life and Environmental Sciences, University of Tsukuba, Tsukuba 305-8572, Japan.
Pathogens. 2020 Apr 1;9(4):257. doi: 10.3390/pathogens9040257.
The order Trypanosomatida has been well studied due to its pathogenicity and the unique biology of the mitochondrion. In , four DNA polymerases, namely PolIA, PolIB, PolIC, and PolID, related to bacterial DNA polymerase I (PolI), were shown to be localized in mitochondria experimentally. These mitochondrion-localized DNA polymerases are phylogenetically distinct from other family A DNA polymerases, such as bacterial PolI, DNA polymerase gamma (Polγ) in human and yeasts, "plant and protist organellar DNA polymerase (POP)" in diverse eukaryotes. However, the diversity of mitochondrion-localized DNA polymerases in Euglenozoa other than Trypanosomatida is poorly understood. In this study, we discovered putative mitochondrion-localized DNA polymerases in broad members of three major classes of Euglenozoa-Kinetoplastea, Diplonemea, and Euglenida-to explore the origin and evolution of trypanosomatid PolIA-D. We unveiled distinct inventories of mitochondrion-localized DNA polymerases in the three classes: (1) PolIA is ubiquitous across the three euglenozoan classes, (2) PolIB, C, and D are restricted in kinetoplastids, (3) new types of mitochondrion-localized DNA polymerases were identified in a prokinetoplastid and diplonemids, and (4) evolutionarily distinct types of POP were found in euglenids. We finally propose scenarios to explain the inventories of mitochondrion-localized DNA polymerases in Kinetoplastea, Diplonemea, and Euglenida.
由于锥虫目具有致病性以及线粒体独特的生物学特性，该目已得到充分研究。在[具体研究中]，实验表明四种与细菌DNA聚合酶I（PolI）相关的DNA聚合酶，即PolIA、PolIB、PolIC和PolID，定位于线粒体中。这些定位于线粒体的DNA聚合酶在系统发育上与其他A家族DNA聚合酶不同，如细菌PolI、人类和酵母中的DNA聚合酶γ（Polγ）、多种真核生物中的“植物和原生生物细胞器DNA聚合酶（POP）”。然而，除锥虫目外，眼虫纲中定位于线粒体的DNA聚合酶的多样性了解甚少。在本研究中，我们在眼虫纲的三个主要类别——动基体目、双滴虫目和裸藻目——的广泛成员中发现了假定定位于线粒体的DNA聚合酶，以探索锥虫科PolIA - D的起源和进化。我们揭示了这三个类别中定位于线粒体的DNA聚合酶的不同情况：（1）PolIA在这三个眼虫纲类别中普遍存在，（2）PolIB、C和D局限于动基体目，（3）在原动基体目和双滴虫目中鉴定出新型的定位于线粒体的DNA聚合酶，（4）在裸藻目中发现了进化上不同类型的POP。我们最终提出了一些设想来解释动基体目、双滴虫目和裸藻目中定位于线粒体的DNA聚合酶的情况。
