Cornet Valérie, Henry Joël, Corre Erwan, Le Corguille Gildas, Zanuttini Bruno, Zatylny-Gaudin Céline
Université de Caen Basse-Normandie, IBFA, F-14032 Caen, France; UMR BOREA, MNHN, UPMC, CNRS-7208, IRD-207, UCBN, F-14032 Caen, France.
Université de Caen Basse-Normandie, IBFA, F-14032 Caen, France; UMR BOREA, MNHN, UPMC, CNRS-7208, IRD-207, UCBN, F-14032 Caen, France; Post Genomic Platform PROTEOGEN, Université de Caen Basse-Normandie, F-14032 Caen, France.
J Proteomics. 2014 Aug 28;108:209-22. doi: 10.1016/j.jprot.2014.05.019. Epub 2014 Jun 2.
We characterized the proteome of the posterior salivary glands of the cephalopod S. officinalis by combining de novo RNA sequencing and mass spectrometry. In silico analysis of the transcriptome revealed the occurrence of three main categories of proteins: enzymes, immune factors and toxins. Protein identification by SDS-PAGE and MALDI-TOF/TOF confirmed the occurrence of proteins essential to venom-like enzymes: peptidase S1 under four isoforms, phospholipase A2 and two toxins. The first toxin is a cystein rich secreted protein (CRISP), a common toxin found in all venomous animals. The second one is cephalotoxin, which is specific to decabrachia cephalopods. Secretions of the posterior salivary glands are transported to the cephalopodium; they are involved in prey catching but also in gamete storage, fertilization and egg-laying. The paralyzing activity and the antimicrobial effect of saliva suggest a dual role in predation and in immune defense in cuttlefish.
The originality of this study lies in the use of a transcriptomic approach (de novo RNA sequencing) coupled to a proteomic approach to get an overview of posterior salivary glands in S. officinalis. In cephalopods, these glands are involved in predation, more precisely in paralyzing preys and digesting them. Our in silico analysis equally reveals a role in immune defense as observed in mammals' saliva. Our study also shows the specificity of cuttlefish venom, with the identification of cephalotoxins, proteins that are not found in octopuses. Finally, we show that cuttlefish saliva is a complex mixture that has antibacterial and crippling properties, but no lethal effect.
我们通过将从头RNA测序和质谱分析相结合，对乌贼（Sepia officinalis）后唾液腺的蛋白质组进行了表征。转录组的计算机分析揭示了三类主要蛋白质的存在：酶、免疫因子和毒素。通过SDS-PAGE和MALDI-TOF/TOF进行的蛋白质鉴定证实了毒液样酶所必需的蛋白质的存在：四种同工型的肽酶S1、磷脂酶A2和两种毒素。第一种毒素是富含半胱氨酸的分泌蛋白（CRISP），这是在所有有毒动物中都能找到的一种常见毒素。第二种是头毒素，它是十足目头足类动物特有的。后唾液腺的分泌物被输送到头部；它们不仅参与捕食，还参与配子储存、受精和产卵。唾液的麻痹活性和抗菌作用表明其在乌贼的捕食和免疫防御中具有双重作用。
本研究的独特之处在于使用转录组学方法（从头RNA测序）与蛋白质组学方法相结合，以全面了解乌贼的后唾液腺。在头足类动物中，这些腺体参与捕食，更确切地说是使猎物麻痹并消化它们。我们的计算机分析同样揭示了其在免疫防御中的作用，这与在哺乳动物唾液中观察到的情况相同。我们的研究还显示了乌贼毒液的特异性，鉴定出了章鱼中不存在的头毒素蛋白。最后，我们表明乌贼唾液是一种具有抗菌和致残特性但无致死作用的复杂混合物。
