Direct cDNA cloning of novel conopeptide precursors of the O-superfamily.
Conotoxins from the venom of marine cone snails (genus Conus) represent large families of proteins exhibiting a similar precursor organization, but highly diverse pharmacological activities. A directed PCR-based approach using primers according to the conserved signal sequence was applied to investigate the diversity of conotoxins from the O-superfamily. Using 3' RACE, cDNA sequences encoding precursor peptides were identified in five Conus species (Conus capitaneus, Conus imperialis, Conusstriatus, Conus vexillum and Conus virgo). In all cases, the sequence of the signal region exhibited high conservancy, whereas the sequence of the mature peptides was either almost identical or highly divergent among the five species. These findings demonstrate that beside a common genetic pattern divergent evolution of toxins occurred in a highly mutating peptide family.
Kauferstein
Silke
S
Zentrum der Rechtsmedizin, University of Frankfurt, Kennedyallee 104, D-60596 Frankfurt, Germany. kauferstein@em.uni.frankfurt.de
Melaun
Christian
C
Mebs
Dietrich
D
D000595:Amino Acid Sequence; D000818:Animals; D003001:Cloning, Molecular; D020916:Conotoxins / Q000737:chemistry* / Q000235:genetics*; D004247:DNA / Q000378:metabolism; D018076:DNA, Complementary / Q000378:metabolism; D019143:Evolution, Molecular; D015723:Gene Library; D008969:Molecular Sequence Data; D008974:Mollusca; D008978:Mollusk Venoms / Q000737:chemistry*; D005810:Multigene Family; D010455:Peptides / Q000737:chemistry* / Q000235:genetics; D010802:Phylogeny; D021382:Protein Sorting Signals; D017386:Sequence Homology, Amino Acid; D012908:Snails
D020916:Conotoxins; D018076:DNA, Complementary; D008978:Mollusk Venoms; D010455:Peptides; D021382:Protein Sorting Signals; D004247:DNA