脊椎动物GSDM基因家族的生物信息学分析

Bioinformatics Analysis of the GSDM Gene Family in Vertebrates

多数脊椎动物的基因组中都存在gasdermin(GSDM)基因家族成员。该家族中的gasdermin D(GSDMD)和gasdermin E(GSDME)与高等动物体内的细胞焦亡紧密相关。然而,目前关于GSDM家族其它成员的研究还比较缺乏,对其系统演化的模式也知之甚少。本研究首先对人GSDM家族基因的基因结构、染色体定位、表达的组织特异性、编码蛋白的理化性质与二级结构进行了生物信息学分析。随后,对18个物种中的GSDM基因家族成员进行系统进化树的构建和选择压力分析。结果表明,人GSDM家族各成员的基因结构和表达的组织分布均存在较大差异。其编码蛋白多为酸性,亲水性高,二级结构则以α-螺旋与无规则卷曲为主。系统发育分析表明,Pejvakin(PJVK)和GSDME存在于脊椎动物的所有类群中,是GSDM基因家族中的原始成员。GSDMB、GSDMC和GSDMD存在于哺乳动物中,可能是由鸟类GSDMA演化而来。选择压力分析表明,GSDMB、GSDMC、GSDME和PJVK均受负选择作用,且以PJVK所受的负选择最强。GSDMD则受到明显的正选择作用。以上结果既可为理解GSDM基因家族的功能提供新线索,又可为进一步针对该家族开展实验研究提供新的参考依据。

The gasdermin(GSDM)gene family widely exists in the genome of vertebrates.Gasdermin D(GSDMD)and gasdermin E(GSDME)play important roles in the pyroptosis of cells from higher animals.However,little is known about other members of GSDM family and its system evolution mode.First of all,this study analyzed gene structure,chromosome distribution,tissue-specific expression,physical/chemical properties,and secondary structures of human GSDM family genes and their encoded proteins through bioinformatical methods.Then,we constructed a phylogenetic tree of GSDM gene family members from 18 species and analyzed the selection pressure.Our results revealed that there were significant differences in gene structure and expression tissue distribution among members of human GSDM family.Most of the proteins encoded by human GSDM family genes were acidic and highly hydrophilic.The majority of secondary structure of these proteins wasα-helices and random coils.Phylogenesis analysis unveiled that pejvakin(PJVK)and GSDME exist in all groups of vertebrates,constituting the original members of the GSDM gene family.GSDMB,GSDMC and GSDMD existed in mammals and may be evolved from GSDMA in birds.Selection pressure analysis showed that GSDMD,GSDMC,GSDME and PJVK were all affected by negative selection and PJVK was the most affected.In contrast,GSDMD undergoes positive selection.The data above not only provided new clues for understanding biological functions of the GSDM gene family,but also provided new potential directions for further experimental researches.