Proteomics of Cephalopod Venoms — ASN Events
  1. Schedule
  2. Lunch/Poster Session One
  3. Proteomics of Cephalopod Venoms

Proteomics of Cephalopod Venoms (#133)

Ira Cooke 1 , Nikeisha Caruana 2 , Brooke Whitelaw 2 , Pierre Faou 3 , Jan Strugnell 2
  1. Latrobe University / VLSCI, BUNDOORA, VIC, Australia
  2. Ecology, Environment and Evolution, La Trobe University, Bundoora, Vic, Australia
  3. Biochemistry, Latrobe University, Melbourne, VIC, 3086
Coleoid Cephalopods are a diverse molluscan sub-class that includes octopus, cuttlefish and squid.  There is strong morphological, behavioural and transcriptomic evidence to suggest that many cephalopod species use a potent cocktail of proteinaceous toxins for predation and/or defense.  Despite this, very few cephalopod proteins have been observed at the protein level and even fewer have been well characterised.  As a consequence they are a conspicuously under-represented group in the Uniprot toxins database and potentially a rich source of novel toxic proteins.

We present our findings based on bottom-up proteomics on venom glands and toxic secretions from three different cephalopod species (two octopus and one squid).  In order to perform this work we relied heavily on integrating information from transcriptomics and proteomics. For all organisms it was necessary to assemble high quality reference transcriptomes and transcriptome maps across multiple tissues. We used these to predict protein sequences and then further refined these predicted protein databases using proteogenomics.  New bioinformatic tools were developed to facilitate these analyses. All these tools are open source and are available via the user-friendly Galaxy platform.


Toxins were identified based on well known general features of toxins, including small size, high cysteine richness, existence of a signal and/or pro peptides and sometimes homology to known toxins.  Further evidence for toxicity was obtained from approximate quantitative protein expression estimates via intensity based absolute quantitation (iBAQ) in venomous secretions as well as relative expression in different tissues based on transcriptomic data.  


Our work highlights the important role that mass spectrometry based proteomics can play in the discovery of novel toxin molecules from poorly studied taxa, and describes the non-standard bioinformatic techniques that enable such work.