Characterization of LmTxLP11 and LmVP1.1 transcripts and genomic organizations: alternative splicing contributing to the diversity of scorpion venom peptides.

Scorpion venoms are rich resources of bioactive peptides with extreme variability. Multiple molecular mechanisms are involved in the diversity of scorpion venom peptides. However, alternative splicing, which plays a major role in the generation of proteomic and functional diversity in metazoan organisms, hasn't been reported in genes coding for scorpion venom peptides. In the EST analysis of venom peptide transcripts from scorpion Lychas mucronatus, we reported an alternative splicing event. Transcripts of LmTxLP11 and LmVP1.1 share identical 5' region. LmVP1.1 is a novel type of scorpion venom peptides constrained by one disulfide bridge, whereas LmTxLP11 is an extended version of LmVP1.1. By transcript alignment with its genomic sequence, it is found that both transcripts are generated from a single gene by alternative poly A site and terminal exon. The gene encoding LmTxLP11 and LmVP1.1 is the first one harboring three introns ever reported from scorpion venoms. This work demonstrates for the first time that alternative splicing is involved in regulating the diversity of scorpion venom peptides.