苦瓜McAGD8和小G蛋白McRABD2c基因全长cDNA的分离及序列分析

Isolation and Sequence Aanalysis Full-length of McAGD8 and Small GTPases Protein Gene McRABD2c in Momordica charantia

构建并筛选苦瓜成熟果实c DNA文库,分离获得2个全长c DNA序列(命名为McRABD2c和McAGD8)。序列分析结果表明:McAGD8长度为1 695 bp,含有1个1 209 bp开放阅读框,编码403个氨基酸,该蛋白含有1个保守的Arf GAP结构域,与黄瓜Cs AGD8-like具有90%的同源性,同甜瓜Cm AGD8具有89%的同源性。McRABD2c长度为1 166 bp,含有1个609 bp开放阅读框,推测编码202个氨基酸,该蛋白含有Rab家族保守的Rab SF(Rab SF1-Rab SF4)模体及特有的Rab F模体(Rab F1-Rab F5);5个G结构域和2个构象变构域(SwitchⅠ、SwitchⅡ)及C末端的CCX序列,同Cs RABD2C-like同源性高达99%。氨基酸同源比对及进化分析结果表明Mc RABD2属于小G蛋白,而McAGD8属于Arf小G蛋白下游的效应基因。

Constructing and screening the ripe fruit c DNA library of Momordica charantia, Two full-length c DNA was isolated and designated as McAGD8 and Mc RABD2 c separately. Sequence analysis showed that the McAGD8 is 1 695 bp in length with a complete 1 209 bp ORF and a Arf GAP domain, and encodes 403 amino acids. The comparison of deduced amino acids sequence revealed that the McAGD8 with 90% and 89% similarity respectively to the Cs AGD8-like of cucumber and Cm AGD8 of melon. The Mc RABD2 c is 1 166 bp in length with a complete 609 bp ORF, and encodes 202 amino acids. Mc RABD2 c protein included conserved Rab SF（Rab SF1-Rab SF4） and Rab F（ Rab F1-Rab F5） motif of Rab GTPases subfamily, and five signature motif of phosphate loop（ G1-G5）, two conformational switch（ Switch Ⅰ 、 Switch Ⅱ） and C-terminal cysteines motif CCX. The Mc RABD2 c showed 99% similarity with Cs RABD2C-like of cucumber. Amino acids similarity and phylogenetic analysis indicated that Mc RABD2 c is a small GTP-binding protein of Rab family, McAGD8 is a downstream effector of small GTP-binding protein Arf family.