棉花MAPKs家族成员的聚类分析

MAP激酶(促分裂原活化蛋白激酶)级联信号通路(MAPKs)由3种级联磷酸化的蛋白激酶MAPKKK、MAPKK和MAPK组成,在调控植物的生长发育、胁迫响应及抗病反应等过程中都起重要作用。为了全面了解棉花MAPK、MAPKK、MAPKKK家族各成员间的关系,进而研究和揭示MAPKs在棉花抗病、抗逆中的作用,利用已公布的雷蒙德氏棉和亚洲棉基因组数据,并从NCBI数据库中收集陆地棉的MAPKs氨基酸序列,运用生物信息学的方法对棉花(陆地棉、雷蒙德氏棉、亚洲棉)MAPK、MAPKK和MAPKKK家族的氨基酸序列进行了同源比对和聚类分析。结果表明:棉花MAPK家族具有特征性结构TEY磷酸化位点或TDY磷酸化位点,依据其氨基酸序列可划分为A、B、C和D族,其中TEY类包含A、B和C族,TDY类只包含D族;棉花MAPKK家族具有特征性保守区域S/T-X5-S/T和活性部位基序D(I/L/V)K,并依据其氨基酸序列也可将其划分为A、B、C和D族;棉花MAPKKK家族具有MEKK特征性保守区域G(T/S)PX(W/Y)MAPEV和Raf特征性保守区域GTXX(W/Y)MAPE(L/V),进而分为MEKK类和Raf类2组亚群。本研究梳理了棉花MAPKs中的MAPK、MAPKK、MAPKKK家族各成员间的关系,为进一步研究棉花MAPKs信号传导途径和揭示其在棉花抗病、抗逆中的作用提供了基础信息。

Phylogenetic Analysis of Cotton MAPK Family Members

As an important and conserved cascade signaling pathway in eukaryotes, the mitogen-activated protein kinase (MAPK) signaling cascade is composed of three kinds of sequentially phosphorylated protein kinases, MAPKKK, MAPKK, and MAPK. MAPKs play an important role in a number of processes including the regulation of plant growth, stress responses, and disease resistance. To fully understand the genetic relationship between cotton MAPK, MAPKK, MAPKKK family members, and further reveal the functional roles of cotton MAPKs in stress responses and disease resistance, we collected amino acid sequences of MAPK, MAPKK, and MAPKKK family members in Gossypium hirsutum from the NCBI database, based on published data of the G. raimondii and G. arboreum genome; then performed homologous comparisons and phylogenetic analysis of family members from G. hirsutum, G. raimondii, and G. arboreum. The results showed that cotton MAPK family members contain Thr-Glu-Tyr (TEY) or Thr-Asp-Tyr (TDY) phosphorylation sites and can be divided into four subfamilies (group A, B, C, and D) according to their amino acid sequences. The TEY subtype can be classified into three groups, A, B, and C, whereas the TDY subtype contains only group D. Cotton MAPKK family members, which have a characteristic conservative S/T-X5-S/T area and the active site motif D(I/L/V)K, can also be divided into four subfamilies (group A, B, C and D) according to their amino acid sequences. Members of the cotton MAPKKK family fall into two main classes: MEK and Raf, with the former containing theconserved region G(T/S)PX(W/Y)MAPEV and the latter GTXX(W/Y)MAPE(L/V). Clarifying the relationships between cotton MAPK, MAPKK, and MAPKKK family members will help us to further to reveal the roles of cotton MAPKs in stress responses and disease resistance.