牛白细胞介素1受体相关激酶2（IRAK2）基因的克隆及生物信息学分析

Toll样受体 (toll-like receptors，TLRs)可识别病原体相关分子模式，通过下游信号转导激活免疫细胞，在天然免疫和适应性免疫应答中起着重要的作用，而白细胞介素1受体相关激酶2(interleukin-1 receptor-associated kinase 2,IRAK2)为TLRs信号转导通路下游重要的分子，起着信号转导与调控作用。为了深入研究牛TLRs信号转导通路对牛病原体所致疾病抗性中的主要作用，采用RT-PCR和RACE方法克隆了牛IRAK2基因的cDNA和进行了基因表达谱分析，并对其基因序列和所编码的蛋白质的结构特征进行了生物信息学分析。结果表明，牛IRAK2基因在乳腺、肝、十二指肠、脂肪、子宫、肾、心、肺、胰和卵巢10个组织中有表达，其序列全长为2 148 bp(GenBank登录号为EU528620)，包括36 bp的5'非翻译区（1~36），1 866 bp的CDS区（37~1 902）和246 bp的3'非翻译区（1 903~2 148），编码622个氨基酸，其分子量为68 628.31 D，等电点为5.3。IRAK2蛋白含有一个DD结构域和一个S_TKc结构域，位于细胞核、细胞质、线粒体和质膜上，通过DD和S_TKc结构域对TLRs的信号转导有着重要的作用。

Cloning of Bovine Interleukin-1 Receptor-associated Kinase 2 (IRAK2) Gene and Its Bio-information Analysis

Toll-like receptors (TLRs) can recognize the pathogen associated molecular pattern and mediate signaling for initiate innate and adaptive immune responses. Interleukin-1 receptor-associated kinase 2 (IRAK2) is one of the important downstream signal molecules in TLRs signal transduction pathways. In order to further study the function and signal transduction of TLRs on the diseases induced by pathogen infection, bovine IRAK2 gene isolated using RT-PCR and RACE experiments was analyzed by bio-informatics and tissues expression profiles. The results showed that bovine IRAK2 gene could be expressed in many tissues including mammary gland, liver, duodenum, fat, womb, kidney, heart, lung, pancreas and ovary. Its cDNA sequence was 2 148 bp (GenBank accession No. EU528620), including 36 bp 5'-UTR, 1 866 bp CDS and 246 bp 3'-UTR. IRAK2 gene codes 622 aa, molecular weight and isoelectric point are 68 628.31 D and 5.3, respectively. IRAK2 protein contained the death domain(DD) and S_TKc domain and located at lots of cell organs such as cell nucleus, cytoplasm, mitochondrium and protoplasmic membrane. It is inferred that IRAK2 may be very important for signaling and regulating on TLRs signal transduction.