Wang Hui, Park Bum Soo, Lim Weol-Ae, Ki Jang-Seu
Department of Biotechnology, Sangmyung University, Seoul 03016, South Korea.
Institute of Natural Sciences, Sangmyung University, Seoul 03016, South Korea.
Gene. 2018 Apr 20;651:70-78. doi: 10.1016/j.gene.2018.02.002. Epub 2018 Feb 3.
Metacaspases (MCAs) are cysteine proteases that share sequence homology with caspases, and may play roles in programmed cell death (PCD). In the present study, we identified a novel MCA gene (CpMCA) from the red tide dinoflagellate Cochlodinium polykrikoides, and examined its molecular characteristics and gene expression in response to algicide-induced cell death. CpMCA cDNA is 1164 bp in length, containing a dinoflagellate spliced leader sequence (dinoSL), an 879-bp open reading frame (ORF), which codes for a 293-aa protein, and a poly (A) tail. Multi-sequence comparison indicated that CpMCA belongs to type I MCA, but it has a different structure at the N-terminal. Phylogenetic analysis showed that C. polykrikoides may have acquired the MCA gene from bacteria by means of horizontal gene transfer (HGT). In addition, expressions of CpMCA significantly increased following exposure to the common algicides copper sulfate and oxidizing chlorine, which trigger cell death in dinoflagellates, suggesting that CpMCA may be involved in cell death.
类半胱天冬酶（MCAs）是一类与半胱天冬酶具有序列同源性的半胱氨酸蛋白酶，可能在程序性细胞死亡（PCD）中发挥作用。在本研究中，我们从赤潮甲藻多环旋沟藻中鉴定出一个新的MCA基因（CpMCA），并研究了其分子特征以及在杀藻剂诱导的细胞死亡过程中的基因表达。CpMCA cDNA长度为1164 bp，包含一个甲藻剪接前导序列（dinoSL）、一个879 bp的开放阅读框（ORF），编码一个293个氨基酸的蛋白质以及一个聚腺苷酸尾。多序列比较表明CpMCA属于I型MCA，但在N端具有不同结构。系统发育分析表明，多环旋沟藻可能通过水平基因转移（HGT）从细菌中获得了MCA基因。此外，暴露于常见杀藻剂硫酸铜和氧化氯后，CpMCA的表达显著增加，这两种杀藻剂会引发甲藻细胞死亡，表明CpMCA可能参与细胞死亡。
