The transcriptome recipe for the venom cocktail of Tityus bahiensis scorpion

Abstract

Scorpion venom is a mixture of peptides, including antimicrobial, bradykinin-potentiating and anionic peptides and small to medium proteins, such as ion channel toxins, metalloproteinases and phospholipases that together cause severe clinical manifestation. Tityus bahiensis is the second most medically important scorpion species in Brazil and it is widely distributed in the country with the exception of the North Region. Here we sequenced and analyzed the transcripts from the venom glands of T. bahiensis, aiming at identifying and annotating venom gland expressed genes. A total of 116,027 long reads were generated by pyrosequencing and assembled in 2891 isotigs. An annotation process identified transcripts by similarity to known toxins, revealing that putative venom components represent 7.4% of gene expression. The major toxins identified are potassium and sodium channel toxins, whereas metalloproteinases showed an unexpected high abundance. Phylogenetic analysis of deduced metalloproteinases from T. bahiensis and other scorpions revealed a pattern of ancient and intraspecific gene expansions. Other venom molecules identified include antimicrobial, anionic and bradykinin-potentiating peptides, besides several putative new venom components. This report provides the first attempt to massively identify the venom components of this species and constitutes one of the few transcriptomic efforts on the genus Tityus.

Insights into the Hypertensive Effects of Tityus serrulatus Scorpion Venom: Purification of an Angiotensin-Converting Enzyme-Like Peptidase

“…venoms [6,9], although transcriptomic studies have identified other classes of enzymes as well [8,17]. Studies from our group have shown that Ts v proteases cleave mammal peptides in vitro, and that this activity is inhibited by high concentrations of commercially available antivenoms used in the treatment of envenomed patients in Brazil [16,18].…”

“…Also, functional ACE-like activity was detected in animal venoms of the fish-hunting cone snail [13], vampire snail [28], and solitary endoparasitic wasp [14]. In scorpions, ACE-like peptidases were detected by transcriptome analysis in Hottentotta judaicus [29], Tityus stigmurus [30], and Tityus bahiensis [17] venoms.…”

Scorpion Potassium Channel-blocking Defensin Highlights a Functional Link with Neurotoxin

“…Genomic, transcriptomic, and proteomic analyses have indicated that venoms contain diverse types of cysteinerich neurotoxins that block or modulate different types of ion channels that open and close to generate electrical signals for nerve cell communication (3)(4)(5)(6). The vast majority of scorpion toxins contain a core topology comprising ␣ helices connected to an antiparallel ␤ sheet stabilized by three or four disulfide bonds, termed the cystine-stabilized ␣/␤ motif, including ChTX 4 from the scorpion Leiurus quinquestriatus hebraeus (7) and BmKTX from the scorpion Mesobuthus martensii (8).…”

Purificação e caracterização de peptidases presentes no veneno do escorpião <i>Tityus serrulatus</i>.

“…venoms [6,9], although transcriptomic studies have identified other classes of enzymes as well [8,17]. Studies from our group have shown that Tsv proteases cleave mammal peptides in vitro, and that this activity is inhibited by high concentrations of commercially available antivenoms used in the treatment of envenomed patients in Brazil [16,18].…”

“…Also, functional ACE-like activity was detected in animal venoms of the fish-hunting cone snail [13], vampire snail [28], and solitary endoparasitic wasp [14]. In scorpions, ACE-like peptidases were detected by transcriptome analysis in Hottentotta judaicus [29], Tityus stigmurus [30], and Tityus bahiensis [17] venoms.…”