Bioinformatics Seminars

Bioinformatics Seminar

Time: 10:45am Tuesdays.
Level 7 Seminar Room 2, WEHI1

1 August 2017

Seminar Room 1

Venom composition, distribution & evolution in Australian endemic sea anemones

Michela Mitchell
WEHI Bioinformatics

Cnidarians (e.g. jelly fish, sea anemones and corals) deliver venoms containing toxins that can affect humans ranging from mild rashes to death. Venom peptides are of interest to the pharmaceutical industry as novel therapeutic leads for the treatment of autoimmune diseases such as Multiple Sclerosis. Sea anemone venom is also known to be cytotoxic to breast cancer cells. Despite the growing interest in sea anemone toxin peptides, there is a lack of knowledge regarding those found in endemic Australian species. Moreover, little is known regarding the distribution of peptides throughout discrete morphological regions of sea anemones.

Each discrete morphological region of a sea anemone, e.g. tentacles, acrorhagi and actinopharynx (throat) has a unique complement of cnidae (the organelles through which venom is delivered). In turn, each discrete morphological region performs a unique biological function and therefore it was hypothesised that they could have a unique peptide profile.

Using transcriptomic, peptidomic and MALDI-IMS (Matrix Absorption/Desorption Laser Imaging Mass Spectrometry) approaches, the composition of peptides throughout discrete morphological tissue regions has been investigated.

The preliminary transcriptome for Oulactis sp., identified novel peptides with homology to several known toxin protein families (e.g. ShK and PLA2). The distribution of peptides in two Oulactis species tissues has been used explored using MALDI-IMS. It was found that while some peptides are distributed ubiquitously throughout the sea anemone, others are restricted to discrete morphological regions. Furthermore, mass spectrometry showed that each morphological region has a unique peptide profile. Two peptides have been selected for structure determination by NMR and will be functionally characterisation. Transcriptomic studies have been extended to other cnidarian species from Australian waters. Sequences with a homology to select toxin families are being incorporated into chemical evolution studies.

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