猪SOSC1、SOCS3和SOCS4基因克隆及组织表达研究

Suppressor of cytokine signaling 1,3 and 4 genes in pigs(Sus scrofa):cDNA cloning and tissue expression

本文以长白猪(Landrace)大脑cDNA为模板,克隆得到长白猪细胞因子抑制因子SOCS-3基因,并首次克隆得到长白猪SOCS-1和SOCS-4基因.此外,还利用长白猪基因组DNA为模板克隆得到SOCS-3假基因(pseudo-SOCS-3).序列分析显示:长白猪SOCS-1基因cDNA编码220个氨基酸的前体蛋白,与人、小鼠、大鼠和牛的氨基酸序列一致性分别为94%、91%、91%和94%;SOCS-3基因cDNA全长690 bp,编码229个氨基酸的前体蛋白,与人、大鼠和小鼠的氨基酸序列一致性高达94%以上;SOCS-4基因cDNA全长1404 bp,整个编码区没有内含子插入,编码441个氨基酸的前体蛋白,与人、大鼠和小鼠的氨基酸序列一致性分别为97%,89%和86%.氨基酸结构分析显示,长白猪SOCS-1,SOCS-3和SOCS-4基因都具有典型的中央SH2结构域和C末端有40个氨基酸的SOCS Box结构域;SOCS-4有长约285个氨基酸的N末端,且没有特殊的结合基序,其长末端存在的生理意义有待进一步研究.采用RT-PCR方法,对长白猪SOCS-1,SOCS-3和SOCS-4基因进行组织表达分析.结果显示它们在所有组织中都有表达.

Using cDNA of Landrace pig brain as the template, the full-length cDNAs of SOCS-1, SOCS- 3, and SOCS-4 genes were cloned. Moreover, a pseudo-SOCS-3 gene was cloned using Landrace genomic DNA as template. SOCS-1 cDNA encodes a protein precursor of 220 amino acids, which shares high amino acid sequence identity with that of human （94%）, rat （91%）, mouse （91%）, cattle （94%）. SOCS-3 cDNA （690bp） encodes a protein precursor of 229 amino acids, which shares high amino acid sequence identity （〉 94%） with that of mammals. The full-length cDNA of SOCS-4 encodes a protein precursor of 441 amino acids which shares high amino acid sequence identity with that of human （97%）, rat （89 %） and mouse （86%）. Further structural analyses indicate that pig SOCS-1, SOCS-3 and SOCS- 4 contain an SH2 domain and a C-terminal SOCS box domain; SOCS-4 contains a large amino-terminus of 285 amino acids with no identifiable protein-interaction motifs. Using RT-PCR assay, the mRNA expression of SOCS-1, SOCS-3, and SOCS4 genes were also examined in adult pig tissues. The results showed that they were widely expressed in all of the tissues examined.