短指软珊瑚(Sinularia acuta)热休克蛋白HSP70家族特征及进化分析

Predicted family characteristics and evolution of the heat shock protein HSP70 in Sinularia acuta

热休克蛋白70(heat shock protein 70, HSP70)在生物细胞或组织免受热或氧化应激等方面起着关键作用,是已知高度保守的蛋白质之一。由于全球环境持续升温,珊瑚大面积白化、死亡,珊瑚如何应对持续升温的抗逆机制是科学研究热点。本研究从高温胁迫短指软珊瑚测序蛋白序列数据库分析鉴定出了28个HSP70蛋白家族成员,均为酸性亲水蛋白,大部分蛋白质结构较为稳定。亚细胞定位表明HSP70蛋白主要分布在珊瑚细胞核、细胞质中,在线粒体、内质网上也有少量分布。信号肽预测表明, 28个HSP70蛋白成员中26个没有信号肽,大部分不属于分泌蛋白,不存在跨膜结构。系统进化树结果表明短指软珊瑚HSP70蛋白家族成员聚成5大类。短指软珊瑚HSP70蛋白家族结构和保守基序分析中预测到了10条保守基序motif分为5个亚族。短指软珊瑚HSP70蛋白家族二级结构主要以α-螺旋和无规则卷曲为主,α-螺旋的含量占比大。28个HSP70家族蛋白中有25个预测到了N-糖基化位点,且位点个数在1~9范围内。28个HSP70家族蛋白均预测到磷酸化位点和O-糖基化位点,总个数分别在41~96和1~23范围内。本研究HSP70家族蛋白结果为今后珊瑚在应对全球升温胁迫中的适应机制等方面研究奠定了基础。

Heat shock protein 70(HSP70)is a highly conserved protein that plays a key role in protecting biological cells or tissues from heat or oxidative stress.Due to the continuous warming of the global environment and the widespread bleaching and death of corals,how corals respond to the stress resistance mechanism of continuous warming is a scientific research hotspot.However,current research on the characteristics of the HSP70 family in corals are relatively rare.In this study,28 members of the HSP70 family were identified by analysis of the Sinularia acuta protein sequences under high temperature stress,all of which were acidic hydrophilic proteins with relatively stable structure.Subcellular localization showed that HSP70 was mainly found in coral nuclei and cytoplasm,with lesser amount in mitochondria and endoplasmic reticulum.Signal peptide predictions showed that 26 of the 28 HSP70 members did not have signal peptides,most of them do not secrete proteins and did not have a transmembrane structure.The phylogenetic tree showed that the members of the S.acuta HSP70 family can be clustered into 5 classes.Analysis of the structure and conserved regions of the hsp70 gene family of S.acuta predicted 10 motifs which could be divided into 5 subfamilies.The main secondary structure of the HSP70 protein in S.acuta wasα-helix followed by random coiling.N-glycosylation sites were predicted in 25 of the 28 HSP70 family proteins,with the number of sites ranging from 1 to 9.All 28 HSP70 family proteins were predicted to have phosphorylation and O-glycosylation sites,with a total number in the range of 41~96 and 1~23,respectively.The results of this study on the HSP70 family lay the foundation for future research on the adaptive mechanisms of corals in response to global warming stress.