Bouzat J L, McNeil L K, Robertson H M, Solter L F, Nixon J E, Beever J E, Gaskins H R, Olsen G, Subramaniam S, Sogin M L, Lewin H A
W.M. Keck Center for Comparative and Functional Genomics, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA.
J Mol Evol. 2000 Dec;51(6):532-43. doi: 10.1007/s002390010117.
We employed a phylogenomic approach to study the evolution of alpha subunits of the proteasome gene family from early diverging eukaryotes. BLAST similarity searches of the Giardia lamblia genome identified all seven alpha proteasome genes characteristic of eukaryotes from the crown group. In addition, a PCR strategy for the amplification of multiple alpha subunit sequences generated single alpha proteasome products for representatives of the Kinetoplastida (Leishmania major), the Parabasalia (Trichomonas vaginalis), and the Microsporidia (Vairimorpha sp., Nosema sp., Endoreticulata sp., and Spraguea lophii). The kinetoplastid Trypanosoma cruzi and the eukaryote crown group Acanthamoeba castellanii yielded two distinct alpha proteasome genes each. The presence of seven distinct alpha proteasome genes in G. lamblia, one of the earliest-diverging eukaryotes, indicates that the alpha proteasome gene family evolved rapidly from a minimum of one gene in Archaea to seven or more in Eukarya. Results from the phylogenomic analysis are consistent with the idea that the Diplomonida (as represented by G. lamblia), the Kinetoplastida, the Parabasalia, and the Microsporidia diverged after the duplication events that originated the alpha proteasome gene family. A model for the early origin and evolution of the proteasome gene family is presented.
我们采用了系统基因组学方法来研究蛋白酶体基因家族α亚基从早期分化的真核生物开始的进化。对蓝氏贾第鞭毛虫基因组进行BLAST相似性搜索，鉴定出了冠群真核生物特有的所有七个α蛋白酶体基因。此外，一种用于扩增多个α亚基序列的PCR策略为动基体目（杜氏利什曼原虫）、副基总纲（阴道毛滴虫）和微孢子虫纲（变异孢虫、 Nosema属、内网状孢虫和洛氏斯普劳格孢子虫）的代表物种产生了单个α蛋白酶体产物。动基体锥虫和真核生物冠群的卡氏棘阿米巴各自产生了两个不同的α蛋白酶体基因。最早分化的真核生物之一蓝氏贾第鞭毛虫中存在七个不同的α蛋白酶体基因，这表明α蛋白酶体基因家族从古菌中最少的一个基因迅速进化到真核生物中的七个或更多基因。系统基因组学分析的结果与双滴虫目（以蓝氏贾第鞭毛虫为代表）、动基体目、副基总纲和微孢子虫纲在产生α蛋白酶体基因家族的复制事件之后分化的观点一致。本文提出了蛋白酶体基因家族早期起源和进化的模型。
