Transcriptomic and Proteomic Analysis of the Tentacles and Mucus of Anthopleura dowii Verrill, 1869.

Santos Ramírez-Carreto,Johanna Bernaldez-Sarabia,Rosario Vera-Estrella,Tobías Portillo-Bobadilla,Enrique Rudiño-Piñera,Estefanía Rodríguez,Claudia Rodríguez-Almazán,Jerome J Verleyen,Alexei Licea-Navarro

doi:10.3390/md17080436

Abstract

Sea anemone venom contains a complex and diverse arsenal of peptides and proteins of pharmacological and biotechnological interest, however, only venom from a few species has been explored from a global perspective to date. In the present study, we identified the polypeptides present in the venom of the sea anemone Anthopleura dowii Verrill, 1869 through a transcriptomic and proteomic analysis of the tentacles and the proteomic profile of the secreted mucus. In our transcriptomic results, we identified 261 polypeptides related to or predicted to be secreted in the venom, including proteases, neurotoxins that could act as either potassium (K+) or sodium (Na+) channels inhibitors, protease inhibitors, phospholipases A2, and other polypeptides. Our proteomic data allowed the identification of 156 polypeptides—48 exclusively identified in the mucus, 20 in the tentacles, and 88 in both protein samples. Only 23 polypeptides identified by tandem mass spectrometry (MS/MS) were related to the venom and 21 exclusively identified in the mucus, most corresponding to neurotoxins and hydrolases. Our data contribute to the knowledge of evolutionary and venomic analyses of cnidarians, particularly of sea anemones.

Highlights

Sea anemones are among the oldest animals with the ability to produce venom, which is used in defense, depredation, and intra-specific competition [1,2]
In order to explore the components of the venom from the transcriptome data and to generate a database to complement our proteomic mucus and tentacle data, we selected transcripts with higher identity with protein databases using a protein query (BLASTP) that were linked to components of the venom in our automatically generated annotation, and analyzed their corresponding amino acid sequences in detail one by one
Using existing information on the components of the venom of sea anemones, as well as that obtained from our data analyses, we describe a set of sequences of peptides and proteins with pharmacological potential exclusively identified in the transcriptome of the tentacle of A. dowii

Summary

Introduction

Sea anemones are among the oldest animals with the ability to produce venom, which is used in defense, depredation, and intra-specific competition [1,2]. Mar. Drugs 2019, 17, 436 anemones concentrate their venom in structures called cnidae, distributed across the different regions of the polyp (tentacles, acrorhagi, actinopharynx, column, mesenterial filaments), but with major abundances in the tentacles [3,4,5]. The most frequently studied sea anemone toxin is the ShK toxin from Stichodactyla helianthus [10]. This peptide has the ability to block the Kv1.3 channels of T lymphocytes, inhibiting their activation and acting as an immunosuppressant [11,12]. The analgesic polypeptides 1-3 (APHC1-3) from sea anemone Heteractis crispa inhibit the pain vanilloid receptor (TRPV1), which is involved in conditions such as peripheral neuropathic pain, epilepsy and cancer pain [15,16,17]

Methods

Results

Conclusion