梅花鹿鹿茸尖端组织Tβ-4基因全长cDNA的分离与生物信息学分析

Isolation and Bioinformatics Analysis of Tβ-4 Full Length cDNA in Sika Deer( Cervus nippon hortulorum) Velvet Tip Tissue

胸腺素β4(Thymosinβ4,Tβ-4)是真核生物细胞中的一种具有多重生物学功能的肌动蛋白螯合分子。本研究首次从梅花鹿鹿茸尖端组织全长cDNA文库中成功克隆了Tβ-4基因的全长cDNA序列,并结合生物信息学方法对该基因的氨基酸序列进行了分析。结果表明,梅花鹿Tβ-4基因cDNA全长为770 bp,编码44个氨基酸,相对分子质量为5 052.65 u,理论等电点为5.02,其一级结构中赖氨酸和谷氨酸残基所占比例最高,二级结构元件主要以α-螺旋和无规则卷曲为主。结构分析发现,Tβ-4蛋白氨基酸序列含有"Thymosin family"结构域,没有N端信号肽,没有跨膜区。同源序列分析表明,梅花鹿与白颊长臂猿、人、牛的亲缘关系较近,氨基酸同源性高于85%。Tβ-4在鹿茸尖端组织全长cDNA文库中高丰度表达,提示它可能在鹿茸生长发育中起到重要调节作用。

Thymosin β4 （Tβ- 4 ）is an actin chelating molecule with multiple biological functions in eukaryotic cells. We isolated the full - length cDNA of the Tβ - 4 gene from velvet tip tissue full - length cDNA library of Sika Deer, and analyzed the bioinformatics of the amino acid sequence. The results showed the full - length cDNA of the Tβ -4 gene was 770 bp, encoding a peptide of 44 amino acids. The relative molecular weight of the peptide was 5 052. 65u, isoelectric point was 5.02, and Lys and Glu occupied the highest proportion in primary structure, a - helix and random coil- based were dominant in the secondary structure. Structure analysis showed that the Tβ -4 protein contained a ＂Thymosin family＂ structural domain without and N - terminal signal peptide and transmembrane domain. Homologous sequence analysis indicated that sika deer was close to Bos mutus, Homo sapiens and Nomascus leucogenys （ the amino acids homology was higher than 85% ）. Tβ-4 gene has a higher expression level in velvet tip tissue full - length cDNA library, in- dicating that this gene may play a regulatory role in growth development of velvet antler.