CBL-CIPK信号系统参与小桐子抗冷性形成的生物信息学分析

Bioinformatics analysis of CBL-CIPK signaling system participating in the formation of cold resistance in Jatropha curcas

关键词:  小桐子, 蛋白激酶, CBL-CIPK, 基因家族, 表达分析, 抗冷性

Key words:  Jatropha curcas, protein kinase, CBL-CIPK, gene family, expression analysis, cold resistance

摘要:

类钙调磷酸酶B亚基蛋白(calcineurin B-like calcium sensor,CBL)属Ca²⁺结合蛋白,通过与类钙调磷酸酶B亚基互作蛋白激酶(calcineurin B-like calcium sensor interacting protein kinase,CIPK)互作介导Ca²⁺信号转导过程。CBL-CIPK信号系统参与了植物对多种逆境胁迫的响应过程。为深入探讨小桐子的抗冷性机制,该研究基于BLAST序列比对的方法,在全基因组水平对小桐子CBL与CIPK基因家族进行了鉴定,并对其系统进化、基因结构、表达特性及功能互作进行了解析。结果表明:(1)在小桐子基因组中共鉴定到8个CBL基因与18个CIPK基因,CBL与CIPK蛋白长度分别在211～257 aa与422～484 aa之间,等电点分别在4.65～5.08与6.20～9.26之间。(2)另外,CBL基因家族都包含8～10个外显子,而CIPK基因家族分为显著的1～2个外显子(11个基因)和12～15个外显子(7个基因)两类。(3)多序列比对显示,小桐子CBL蛋白都鉴定到1个由14个氨基酸残基组成的非典型EF-hand基序与3个取代程度不同的典型EF-hand基序,而CIPK蛋白都包含N端激酶结构域与C端自抑制FISL/NAF结构域。(4)染色体定位显示,26个小桐子CBL与CIPK基因不均匀地分布于9条染色体上。(5)转录组数据分析表明,大部分CBL与CIPK基因在小桐子叶片、根及种子中都有高水平表达,其中JcCIPK14与JcCIPK18在低温处理时上调表达量达到了极显著水平(P<0.01),参与小桐子的抗冷性过程。综上结果为开展小桐子CBL和CIPK基因的功能鉴定与低温信号转导机制研究提供了借鉴。

Abstract:

Calcineurin B-like calcium sensor(CBL)is a Ca²⁺-binding protein that mediates the Ca²⁺ signal transduction process by interacting with Calcineurin B-like calcium sensor interacting protein kinase(CIPK). CBL-CIPK signaling system is involved in the response of plants to a variety of stress conditions. For insight into the chilling mechanism of CBL and CIPK in Jatropha curcas, the CBL and CIPK gene families were identified from J. curcas based on the BLAST method, and then the phylogenetic relationship, gene structure, expression profile, and functional interaction were analyzed. The results were as follows:(1)A total of 8 CBL and 18 CIPK genes were identified from J.curcas genome. The protein length of CBLs and CIPKs ranged from 211 to 257 aa and 422 to 484 aa, respectively, and the putative isoelectric point ranged from 4.65 to 5.08 and 6.20 to 9.26, respectively.(2)Furthermore, all the CBL genes family contained 8-10 exons, while the CIPK genes family were divided into significant 1-2 exons(11 genes)and 12-15 exons(7 genes).(3)Sequence alignment revealed that CBL proteins identified 1 atypical EF-hand motif consisting of 14 amino acid residues and three typical EF-hand motifs with different substitutions, while CIPK proteins contained kinase domains in N-terminal and self-inhibiting FISL/NAF domains in C-terminal.(4)Chromosome mapping analysis indicated that 26 J. curcas CBL and CIPK genes were distributed with different densities on nine chromosomes.(5)Transcriptome data analysis showed that most of the CBL and CIPK genes were highly expressed in J. curcas leaves, roots and seeds. Among them, the up-regulated expression of JcCIPK14 and JcCIPK18 reached significant levels under cold stress, which was involved in the cold resistance of J. curcas. All the results of this study might lay a significant foundation for further studies on the gene function and chilling signaling transduction mechanism of CBL and CIPK gene families in J. curcas.