Molecular Diversification of Peptide Toxins from the Tarantula Haplopelma hainanum (Ornithoctonus hainana) Venom Based on Transcriptomic, Peptidomic, and Genomic Analyses

Abstract

The tarantula Haplopelma hainanum (Ornithoctonus hainana) is a very venomous spider found widely in the hilly areas of Hainan province in southern China. Its venom contains a variety of toxic components with different pharmacological properties. In the present study, we used a venomic strategy for high-throughput identification of tarantula-venom peptides from H. hainanum. This strategy includes three different approaches: (i) transcriptomics, that is, EST-based cloning and PCR-based cloning plus DNA sequencing; (ii) peptidomics, that is, off-line multiple dimensional liquid chromatography coupled with mass spectrometry (MDLC-MS) plus peptide sequencing (direct Edman sequencing and bottom-up mass spectrometric sequencing); (iii) genomics, that is, genomic DNA cloning plus DNA sequencing. About 420 peptide toxins were detected by mass spectrometry, and 272 peptide precursors were deduced from cDNA and genomic DNA sequences. After redundancy removal, 192 mature sequences were identified by three approaches. This is the largest number of peptide toxin sequences identified from a spider species so far. On the basis of precursor sequence identity, peptide toxins from the tarantula H. hainanum venom can be classified into 11 superfamilies (and related families). Our results revealed that gene duplication and focal hypermutation may be responsible for the enormous molecular diversity in spider peptide toxins. The current work is an initial overview for the study of tarantula-venom peptides in parallel transcriptomic, peptidomic, and genomic analyses. It is hoped that this work will also provide an effective guide for high-throughput identification of peptide toxins from other spider species, especially tarantula species.

A comparative study of the molecular composition and electrophysiological activity of the venoms from two fishing spiders Dolomedes mizhoanus and Dolomedes sulfurous

“…Their studies demonstrated that the molecular weight distribution was bimodal in the 55 tarantula venoms, with the majority of peptides in the 3000-5000 Da mass range, and a second less pronounced group in the 6500-8500 Da range (Escoubas et al, 2006). Similar results were also obtained in our previous studies of venoms from Chinese tarantula spiders, such as Ornithoctonus hainana (Tang et al, 2010) and Chilobrachys jingzhao (Liao et al, 2007).…”

Weaponization of a Hormone: Convergent Recruitment of Hyperglycemic Hormone into the Venom of Arthropod Predators

“…A search of the recently published genome of the velvet spider Stegodyphus mimosarum (Araneomorphae) (Sanggaard et al, 2014), revealed an ITP/CHH-like gene (Genbank: AZAQ01021694.1) containing an unusually large intron ($9.7 kb) in the same position within the mature peptide as in S. maritima. Moreover, unlike araneomorph spiders (Krapcho et al, 1995), mygalomorphs appear to express intronless toxin genes Pineda et al, 2012;Tang et al, 2010), possibly indicating an inability to splice transcripts expressed in the toxin-producing regions of the venom gland.…”

Spider Transcriptomes from Venom Glands: Molecular Diversity of Ion Channel Toxins and Antimicrobial Peptide Transcripts

“…Remarkably, some of these peptides develop a dual function; that is, they have the ability to act as serine protease inhibitors and potassium channel blockers. The classical architecture of Kunitz-type peptides includes a short N-terminal 3 10 -helix, a C-terminal α-helix, and three strands of antiparallel β-structure, stabilized by three disulfide bridges linked as I-V, II-IV, and III-V (Vassilevski et al 2009;Tang et al 2010). …”

“…There are several reports concerning the description of sodium toxin precursors (NaTx precursors) based on analyses of cDNA from spider venom glands (Satake et al 2004;Jiang et al 2008a;Tang et al 2010). The molecular organization of such precursors (amino acid sequences deduced from cDNA) has been following the general prepropeptide architecture, which is submitted to post-translational processes in order to produce the mature toxin (Figs.…”