Biochemical, Transcriptomic and Proteomic Analyses of Digestion in the Scorpion Tityus serrulatus: Insights into Function and Evolution of Digestion in an Ancient Arthropod

Autor(es)

Fuzita, Felipe J. ^{[1, 2]} ; Pinkse, Martijn W. H. ^[3] ; Patane, Jose S. L. ^[4] ; Juliano, Maria A. ^[5] ; Verhaert, Peter D. E. M. ^[3] ; Lopes, Adriana R. ^[2]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Biotechnol Program, Sao Paulo - Brazil

^[2] Inst Butantan, Biochem & Biophys Lab, Sao Paulo - Brazil

^[3] Delft Univ Technol, Lab Analyt Biotechnol & Innovat Peptide Biol, Delft - Netherlands

^[4] Univ Sao Paulo, Inst Chem, Dept Biochem, Sao Paulo - Brazil

^[5] Univ Fed Sao Paulo, Dept Biophys, Sao Paulo - Brazil

• Tipo de documento: Artigo Científico
• Fonte: PLoS One; v. 10, n. 4 APR 15 2015.
• Citações Web of Science: 10

Resumo

Scorpions are among the oldest terrestrial arthropods and they have passed through small morphological changes during their evolutionary history on land. They are efficient predators capable of capturing and consuming large preys and due to envenomation these animals can become a human health challenge. Understanding the physiology of scorpions can not only lead to evolutionary insights but also is a crucial step in the development of control strategies. However, the digestive process in scorpions has been scarcely studied. In this work, we describe the combinatory use of next generation sequencing, proteomic analysis and biochemical assays in order to investigate the digestive process in the yellow scorpion Tityus serrulatus, mainly focusing in the initial protein digestion. The transcriptome generated database allowed the quantitative identification by mass spectrometry of different enzymes and proteins involved in digestion. All the results suggested that cysteine cathepsins play an important role in protein digestion. Two digestive cysteine cathepsins were isolated and characterized presenting acidic characteristics (pH optima and stability), zymogen conversion to the mature form after acidic activation and a cross-class inhibition by pepstatin. A more elucidative picture of the molecular mechanism of digestion in a scorpion was proposed based on our results from Tityus serrulatus. The midgut and midgut glands (MMG) are composed by secretory and digestive cells. In fasting animals, the secretory granules are ready for the next predation event, containing enzymes needed for alkaline extra-oral digestion which will compose the digestive fluid, such as trypsins, astacins and chitinase. The digestive vacuoles are filled with an acidic proteolytic cocktail to the intracellular digestion composed by cathepsins L, B, F, D and legumain. Other proteins as lipases, carbohydrases, ctenitoxins and a chitolectin with a perithrophin domain were also detected. Evolutionarily, a large gene duplication of cathepsin L occurred in Arachnida with the sequences from ticks being completely divergent from other arachnids probably due to the particular selective pressures over this group. (AU)

• Processo FAPESP: 05/02486-1 - A digestão em Arachnida e a regulação da atividade proteolítica
• Beneficiário: Adriana Rios Lopes
• Linha de fomento: Auxílio à Pesquisa - Regular
• Processo FAPESP: 06/03474-0 - Identificação de peptidases envolvidas na digestão em Tityus serrulatus
• Beneficiário: Felipe Jun Fuzita
• Linha de fomento: Bolsas no Brasil - Iniciação Científica