cDNA cloning of conotoxins with framework XII from several Conus species

• Published in: Acta biochimica et biophysica Sinica 2010-09, Vol.42 (9), p.656-661
• Main Authors: Liu, Zhuguo, Yu, Zheng, Liu, Na, Zhao, Chongjia, Hu, Jie, Dai, Qiuyun
• Format: Article
• Language: English
• Subjects: Amino Acid Sequence; Animals; Base Sequence; cDNA克隆; Cloning, Molecular; Cluster Analysis; Conotoxins - classification; Conotoxins - genetics; Conus Snail - classification; Conus Snail - genetics; Conus Snail - metabolism; Cysteine - genetics; DNA, Complementary - chemistry; DNA, Complementary - genetics; Molecular Sequence Data; Phylogeny; Protein Precursors - genetics; Protein Sorting Signals - genetics; Sequence Analysis, DNA; Sequence Homology, Amino Acid; Species Specificity; 信号肽序列; 信息产业部; 半胱氨酸; 芋螺毒素; 超家族
• ISSN: 1672-9145; 1745-7270
• DOI: 10.1093/abbs/gmq066

In our efforts for cloning novel I2-superfamily conotoxins using the signal peptide sequence, we identified a novel conotoxin Lt12.4 from Conus litteratus. This gene has a framework XII （-C-C-C-C-CC-C-C-）, which is distinct from the cysteine pattern I2-superfamily conotoxin （-C-C-CC- CC-C-C-）. Subsequently, we found the signal peptide sequence of Lt12.4 by 5′-RACE. Using this new sequence, we identified another five novel conotoxins with this cysteine pattern from four Conus species （Conus eburneus, Conus imperialis, Conus marmoreus, and C. litteratus）. These novel conotoxins have the same cysteine pattern as the reported GIa-TxX and GIa-MII, and may contain Gla residues. Furthermore, they have the highly conserved signal peptide and hypervariable mature peptide sequences, and widely exist in Conus species. Therefore, it could be defined as a new superfamily of E-conotoxins.