Cloning, Characterization, and Expression Analysis of the Novel Acetyltransferase Retrogene Ard1b in the Mouse
Cloning, Characterization, and Expression Analysis of the Novel Acetyltransferase Retrogene Ard1b in the Mouse
复制标题
DOI：
10.1095/biolreprod.108.073221
复制
发表时间：
2009-08-01
影响因子：
3.6
通讯作者：
Chan, Wai-Yee
中科院分区：
文献类型：
--
作者：
Pang, Alan Lap-Yin;Peacock, Stephanie;Chan, Wai-Yee
N-α-末端乙酰化是大多数真核蛋白质上协同发生的修饰过程。负责这一过程的主要酶，N-α-末端乙酰转移酶，由催化亚基ARD 1A和辅助亚基NAT 1组成。我们克隆，表征，并研究了Ard 1b（也称为Ard 2），小鼠Ard 1a的新同源物的表达模式。基因组结构的比较表明，常染色体Ard 1b是X连锁Ard 1a的逆转录拷贝。表达分析表明，睾丸优势的Ard 1b。Ard 1a和Ard 1b之间的相互表达模式也观察到在精子发生过程中，表明Ard 1b的表达，以弥补损失的Ard 1a从减数分裂开始。ARD 1A和ARD 1B在体外均能与NAT 1相互作用，构成功能性的N-α-末端乙酰转移酶。ARD 1B蛋白的表达可以在小鼠睾丸中检测到，但延迟到圆形精子细胞的第一次出现。在细胞培养模型中，包含Ard 1b的长3'非翻译区导致荧光素酶报告基因活性降低，这暗示其在精子发生期间Ard 1b的翻译抑制中的作用。我们的研究结果表明，ARD 1B可能有一个重要的作用，在后期的精子发生过程。
N-alpha-terminal acetylation is a modification process that occurs cotranslationally on most eukaryotic proteins. The major enzyme responsible for this process, N-alpha-terminal acetyltransferase, is composed of the catalytic subunit ARD1A and the auxiliary subunit NAT1. We cloned, characterized, and studied the expression pattern of Ard1b (also known as Ard2), a novel homolog of the mouse Ard1a. Comparison of the genomic structures suggests that the autosomal Ard1b is a retroposed copy of the X-linked Ard1a. Expression analyses demonstrated a testis predominance of Ard1b. A reciprocal expression pattern between Ard1a and Ard1b is also observed during spermatogenesis, suggesting that Ard1b is expressed to compensate for the loss of Ard1a starting from meiosis. Both ARD1A and ARD1B can interact with NAT1 to constitute a functional N-alpha-terminal acetyltransferase in vitro. The expression of ARD1B protein can be detected in mouse testes but is delayed until the first appearance of round spermatids. In a cell culture model, the inclusion of the long 3' untranslated region of Ard1b leads to reduction of luciferase reporter activity, which implicates its role in translational repression of Ard1b during spermatogenesis. Our results suggest that ARD1B may have an important role in the later course of the spermatogenic process.