马氏珠母贝丝裂原活化蛋白激酶p38的克隆与表达

丝裂原活化蛋白激酶（MAPK）信号通路在细胞对细胞外刺激的反应中起着重要作用。它是一种丝氨酸/苏氨酸蛋白激酶，通过磷酸化级联将细胞外信号传递给细胞。本研究利用cDNA 末端快速扩增(RACE)技术克隆获得PmMAKP p38基因cDNA 全长序列并对其序列进行生物信息学分析；利用实时荧光定量 PCR（qPCR）技术分析了PmMAKP p38在马氏珠母贝不同组织以及不同免疫刺激后的表达水平。结果显示PmMAKP p38 cDNA全长为1516 bp，开放阅读框长度为1071 bp，共编码356个氨基酸，分子量为 40.88 kDa；结构域预测分析表明PmMAPK p38含有MAPK家族典型的S_TKc结构域；多序列比对、进化树构建以及MatGAT计算结果显示PmMAPK p38与其他物种的相似度、保守程度较高；荧光定量分析结果表明该基因在马氏珠母贝中存在广泛表达，在肝胰腺中表达量最高，其次为外套膜，最低是闭壳肌。机体在受到LPS刺激后，相对表达量在2 h达到最高，12 h降到最低，最高约为最低的5倍；哈维氏弧菌刺激后，相对表达量在2 h达到最高，8 h降到最低，最高约为最低的4倍。研究表明，PmMAPK p38可能在马氏珠母贝的免疫反应中起着重要的作用。

Cloning and expression analysis of mitogen-activated protein kinase (MAPK) p38 in pearl oyster Pinctada fucata martensii

The mitogen-activated protein kinase (MAPK) signaling pathway plays an important role in the response of cells to extracellular stimuli. It is a serine/threonine protein kinase that transmits extracellular signals to cells via a phosphorylation cascade. In this study, we used rapid-amplification of cDNA ends (RACE) for cloning and quantitative PCR (qPCR) for detecting the expression pattern of p38 MAPK. Results showed that the full-length cDNA of p38 MAPK of Pinctada fucata martensii (PmMAKP p38) consisted of 1,516 bp, with a 1,071 bp open reading frame (ORF), and that the gene encoded 356 amino acids with an estimated molecular mass of 40.88 kDa . Domain prediction analysis showed that PmMAPK p38 contained the typical of MAPK family S_TKc domain; The results of multiple sequence alignment, evolutionary tree construction and MatGAT calculation show that the gene is highly similar and conservative with other species; qPCR showed that PmMAPK p38 was widely expressed in P.f. martensii, with the highest expression in hepatopancreas, followed by mantle, and the lowest in adductor muscle. After stimulated by LPS, the relative expression reached the highest at 2 h and decreased to the lowest at 12 h, and the highest was about 5 times of the lowest; After stimulation by Vibrio harveyi, the relative expression reached the highest at 2 h and decreased to the lowest at 8 h, and the highest was about 4 times the lowest. Studies have shown that PmMAPK p38 may play an important role in the immune response of P.f. martensii.