摘要
【目的】探究CrGPAT在莱茵衣藻(Chlamydomonas reinhardtii)油脂合成中的作用。【方法】通过RT-PCR方法克隆了莱茵衣藻CrGPAT基因,对其理化性质、信号肽、蛋白结构域、高级结构进行分析,构建系统发育树。采用荧光定量PCR检测CrGPAT基因表达量。【结果】结果表明,CrGPAT基因编码区全长为1233 bp,共编码410个氨基酸。GPAT相对分子质量为102 kDa,等电点为4.94,平均疏水性为0.805,脂肪系数为17.85,分子式为C_(3536)H_(5841)N_(1233)O_(1442)S_(415),不稳定指数为45.30,属于不稳定蛋白质,为非分泌蛋白且不具有信号肽和蛋白跨膜区。二级结构预测表明CrGPAT蛋白由4种结构组成,其中α螺旋占43.17%,是CrGPAT蛋白最主要的二级结构。同时,系统发育分析表明,CrGPAT与团藻(Volvox)亲缘关系最近。【结论】CrGPAT能够在衣藻体内正常表达且在缺氮条件下表达量会显著提高,为进一步提高莱茵衣藻体内油脂含量提供理论依据。
[Objective]GPAT(glycerol-3-phosphate acyltransferase)is a key enzyme in TAG synthesis pathway.To reveal its role in the oil synthesis of Chlamydomonas reinhardtii.[Methods]In this study,the CrGPAT gene was cloned by RT-PCR.The physical and chemical properties,signal peptide,protein domain and high-level structure were analyzed,and the phylogenetic tree was constructed.[Results]The full-length cDNA of this gene is 1233 bp,encodes a total of 410 amino acids.GPAT has a relative molecular mass of 102 kDa,an isoelectric point of 4.94,an average hydrophobicity of 0.805,a lipid coefficient of 17.85,a molecular formula of C_(3536)H_(5841)N_(1233)O_(1442)S_(415),and an instability index of 45.30,making it an unstable protein.It is a non-secretory protein and does not have a signal peptide or protein transmembrane region.The secondary structure prediction showed that CrGPAT protein consisted of four structures,among whichα-helix accounted for 43.17%and was the most dominant secondary structure of CrGPAT protein.According to the phylogentic tree,CrGPAT was closest relative to Volvox.[Conclusion]CrGPAT could be normally expressed in Chlamydomonas reinhardtii and its expression level was significantly increased under nitrogen deficiency conditions.This study lays a theoretical basis for further improving the lipid content in Chlamydomonas reinhardtii.
作者
贺志敏
张峻鑫
于丽平
胡康
石睿
黄体冉
杨明峰
HE Zhimin;ZHANG Junxin;YU Liping;HU Kang;SHI Rui;HUANG Tiran;YANG Mingfeng(College of Biological and Resource Environment,Beijing University of Agriculture,Beijing 102206,China)
出处
《北京农学院学报》
2023年第3期12-15,共4页
Journal of Beijing University of Agriculture
基金
北京市属高等学校高水平教学创新团队建设支持计划项目(BPHR20220211)。
