荒漠甲虫小胸鳖甲胞外信号调节激酶ERK基因的克隆与低温表达谱分析

Cloning and expression analysis of extracellular signal- regulated kinase ERK gene from the desert beetle Microdera punctipennis

昆虫属变温生物,冷胁迫是其最常见的环境刺激。丝裂原活化蛋白激酶(MAPK)信号通路与细胞应对外界刺激密切相关,为了解MAPK信号通路在荒漠甲虫小胸鳖甲耐寒机制中的作用,从小胸鳖甲4℃转录组数据中筛选出胞外信号调节激酶(ERK)基因的全长c DNA,命名为Mp ERK。生物信息学分析表明,Mp ERK全长1125 bp,编码374个氨基酸。Mp ERK的理论分子量是43 k Da,含有ERK激酶所共有的磷酸化位点,属于MAPK超家族,与其它物种ERK的一致性达80%以上。实时定量PCR检测Mp ERK基因在低温下的表达谱发现,4℃处理1 h后,Mp ERK基因的表达上调为对照的7.5倍,5 h时达到高峰,为对照的15倍。-4℃处理1 h后,Mp ERK基因的表达上调为对照的8.4倍,5 h时达到高峰,为对照的13.75倍。研究结果表明Mp ERK基因是冷响应的,可能在小胸鳖甲应对低温时发挥信号转导作用。

Cold stress is one of the most common environmental stimuli to insect. MAPK signaling pathway is closely related to cellular response to external stimuli. To study the function of MAPK signaling pathway in the cold hardy mechanism of the desert beetle Microdera punctipennis,a c DNA of an extracellular signal-regulated protein kinase（ ERK） gene,designated as Mp ERK,was selected from the transcriptomic data of M. punctipennis that was treated for three hours at 4℃. Bioinformatic analysis showed that the full length of Mp ERK was 1125 bp,encoding 374 amino acids. The predicted molecular mass of Mp ERK was 43 k Da,containing the highly conserved kinase phosphorylation site. Mp ERK belonged to MAPK superfamily,and shared over 80% identity with that of other species. Real-time quantitative PCR analysis showed that after treated the insect was at 4℃ for 1 h,the expression of Mp ERK was upregulated as 7. 5 fold of the control,and 15 fold of the control after 5 h treatment. The expression of Mp ERK was also induced by- 4℃ in that it was 8. 4 fold and 13. 75 fold of the control after1 h and 5 h treatment respectively. Our results indicated that Mp ERK is cold responsive,and may play role in signal transduction in M. punctipennis when it is exposed to low temperatures.