雨生红球藻虾青素酰基转移酶的鉴定与功能研究  

IDENTIFICATION AND FUNCTIONAL STUDY OF ASTAXANTHIN ACYLTRANSFERASE IN HAEMATOCOCCUS PLUVIALIS

作　　者：曹黎 马海燕 魏自旺 赵亮 伍小颖 严海龙 胡强[1] 韩丹翔[1] CAO Li;MA Hai-Yan;WEI Zi-Wang;ZHAO Liang;WU Xiao-Ying;YAN Hai-Long;HU Qiang;HAN Dan-Xiang(Center for Microalgal Biotechnology and Biofuels,Institute of Hydrobiology,Chinese Academy of Sciences,Wuhan 430072,China;University of Chinese Academy of Sciences,Beijing 100049,China)

机构地区：[1]中国科学院水生生物研究所藻类生物技术和生物能源中心,武汉430072 [2]中国科学院大学,北京100049

出　　处：《水生生物学报》2020年第5期1143-1151,共9页Acta Hydrobiologica Sinica

基　　金：国家自然科学基金(31570304)资助。

摘　　要：为研究雨生红球藻(Haematococcus pluvialis)的甘油二酯酰基转移酶(Diacylglycerol acyltransferase, DGAT)是否具有催化虾青素酰基化的功能,首先通过雨生红球藻的cDNA库克隆得到了一个II型DGAT编码区全长序列(DGTT2)。在甘油三酯(Triacylglycerol, TAG)合成缺陷型酵母Saccharomyces cerevisiae H1246中过表达DGTT2基因发现HpDGTT2不能回补H1246的表型,即不具有典型的DGAT功能。利用分离得到的雨生红球藻的内质网成功地建立了一个体外的虾青素酰基转移酶酶活测定体系,添加含有重组HpDGTT2的酵母细胞的微粒体后虾青素酯的含量显著高于对照,初步表明HpDGTT2具有催化雨生红球藻中虾青素酰基化功能。以上结果为进一步探索雨生红球藻中DGTT2的功能及深入理解虾青素合成在代谢水平的调控奠定了基础。This study aimed to unravel whether DGATs are involved in the biological processes of astaxanthin acylation in H.pluvialis.A type II DGAT-encoding gene,DGTT2,was identified in H.pluvialis NIES-144 through RNA-seq and cloned from the cDNA library.Overexpression of HpDGTT2 in the TAG-deficient Saccharomyces cerevisiae strain H1246 failed to rescue the TAG-deficient phenotype,indicating that HpDGTT2 cannot utilize diacylglycerol for TAG biosynthesis.Meanwhile,an in vitro enzymatic assay system for measuring astaxanthin:acyl-CoA acyltransferase activity was established successfully by using H.pluvialis endoplasmic reticulum membranes as crude enzymes.When the S.cerevisiae microsomes containing recombinant HpDGTT2 were incorporated into the system,the concentrations of a number of astaxanthin esters increased significantly compared with the control,which indicated that HpDGTT2 possesses astaxanthin acyltransferase activity.This study will provide a basis for further studies on the function and metabolic regulation of HpDGTT2 in astaxanthin biosynthesis.

关 键 词：雨生红球藻 虾青素 甘油二酯酰基转移酶 内质网 

分 类 号：Q344.1[生物学—遗传学]