Molecular cloning, characterization and evolution of the gene encoding a new group of short‐chain α‐neurotoxins in an Australian elapid, <i>Pseudonaja textilis</i>

Gong, Nanling; Armugam, Arunmozhiarasi; Jeyaseelan, Kandiah

doi:10.1016/s0014-5793(00)01549-0

Cited by 39 publications

(28 citation statements)

References 26 publications

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“…The TIS has been assigned to adenosine (A +" ) at the same position ( Figure 5) as the TIS for PtSntx [18]. The TIS of Pt-bp was further confirmed by a putative TATA box located 31 bp immediately upstream of it.…”

Section: Tis and Regulatory Elements Of The Neurotoxin Genementioning

confidence: 77%

“…Primer-extension analysis was performed [18] to locate the transcription-initiation site (TIS) of the neurotoxin gene. The primer LPEXT (10 pmol ; 5h-GGCACACGATTGTCACCAC3h) was used, labelled at the 5h-end with [γ-$#P]ATP.…”

Section: Primer-extension Analysismentioning

confidence: 99%

“…The activity of the Lntx gene promoter was determined by both chloramphenicol acetyltransferase (CAT) assay and Real-Time PCR (PerkinElmer Applied Biosystems ; [18]). …”

Section: Promoter-activity Analysismentioning

confidence: 99%

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Cloning and characterization of the pseudonajatoxin b precursor

GONG

Armugam

Mirtschin³

et al. 2001

Biochemical Journal

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An Australian common brown snake, Pseudonaja textilis, is known to contain highly lethal neurotoxins. Among them, a long-chain α-neurotoxin, pseudonajatoxin b, has been identified. In this report, while presenting evidence for the presence of at least four such long-chain α-neurotoxins in the venom of P. textilis, we describe the characteristics of both the mRNA and the gene responsible for the synthesis of these neurotoxins. A precursor toxin synthesized from the gene has been identified as being capable of producing the isoforms possibly by post-translational modifications at its C-terminal end. Recombinant toxins corresponding to the precursor and its product have been found to possess similar binding affinities for muscular acetylcholine receptors (IC50 = 3×10−8 M) and a lethality, LD50, of 0.15μg/g in mice.

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Section: Tis and Regulatory Elements Of The Neurotoxin Genementioning

confidence: 77%

Section: Primer-extension Analysismentioning

confidence: 99%

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Cloning and characterization of the pseudonajatoxin b precursor

GONG

Armugam

Mirtschin³

et al. 2001

Biochemical Journal

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“…Advances in transcriptomic and proteomic technologies have contributed to the identification of some of the less abundant toxins within the venom of Australian snakes [19,20]. However, to date only a handful of full-length genomic sequences have been identified for Australian elapids toxins, most notably for the phospholipase A 2 (PLA 2 ) and neurotoxin families from P. textilis [21][22][23]. This study describes the cloning and comparative analysis of two types of kunitz inhibitor along with waprin toxin sequences from a total of eleven Australian elapid snakes, demonstrating a common evolutionary relationship between the three types of toxin.…”

Section: Introductionmentioning

confidence: 99%

Common evolution of waprin and kunitz-like toxin families in Australian venomous snakes

Pierre

Earl

Filippovich

et al. 2008

Cell. Mol. Life Sci.

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The venoms of Australian snakes contain a myriad of pharmacologically active toxin components. This study describes the identification and comparative analysis of two distinct toxin families, the kunitztype serine protease inhibitors and waprins, and demonstrates a previously unknown evolutionary link between the two. Multiple cDNA and full-length gene isoforms were cloned and shown to be composed of three exons separated by two introns. A high degree of identity was observed solely within the first exon which coded for the propeptide sequence and its cleavage site, and indicates that each toxin family has arisen from a gene duplication event followed by diversification only within the portion of the gene coding for the functional toxin. It is proposed that while the mechanism of toxin secretion is highly conserved, diversification of mature toxin sequences allows for the existence of multiple protein isoforms in the venom to adapt to variations within the prey environment.

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“…Not all the snakebites are fatal, yet they may result in the following conditions: permanent physical disability, including limb amputation; chronic ulceration; osteomyelitis with malignant transformation; chronic renal failure; chronic pituitary-adrenal insufficiency; A 2 (PLA 2 s) and cytotoxins (CTXs) are the major components in the venom of the Russell's viper and the Indian cobra, respectively. Both are known to be encoded by multigene families that have evolved through a process of gene duplication followed by accelerated evolution in the protein coding region (7,8,19,20). Therefore, they make a family of toxins with a highly conserved structural fold but widely varying surface amino acid residues.…”

mentioning

confidence: 99%

Molecular diversity in venom proteins of the Russell's viper (Daboia russellii russellii) and the Indian cobra (Naja naja) in Sri Lanka

et al. 2010

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To examine the molecular diversity of the venom proteins of the Russell's viper (Daboia russellii russellii) and the Indian cobra (Naja naja) in Sri Lanka, we isolated 38 venom proteins through a combination of anion exchange chromatography followed by reversed-phase high performance liquid chromatography. From the venom of D. r. russellii we isolated 15 proteins: 5 isozymes of phospholipase A 2 (PLA 2 ), 4 serine proteases, 2 C-type lectin-like proteins, 2 l-amino acid oxidases, 1 cysteine-rich secretory protein (CRISP), and 1 metalloproteinase. From the venom of N. naja we isolated 23 proteins: 10 isoforms of cytotoxins (CTX), 7 PLA 2 isozymes, 2 muscarinic toxinlike proteins, 2 CRISPs, 1 nerve growth factor, and 1 new thrombin-like serine protease. Most of these proteins contained new amino acid sequences for each species, indicating molecular diversity in venom proteins. The entire amino acid sequences of PLA 2 3 from D. r. russellii and CTX7 from N. naja were determined. Additionally, the polymorphic amino acid residues of PLA 2 3 were preferentially localized on the potential antigenic sites. While 2 types of PLA 2 (N and S types) were found in D. r. russellii (India) and D. r. siamensis (Java), all the PLA 2 s from D. r. siamensis (Burma) were N type, and those from D. r. russellii (Sri Lanka) were primarily S type.There are approximately 600 venomous species of snakes in the world. Although there are no accurate figures for the incidence of snakebites, at least 421,000 envenomings and 20,000 deaths are estimated to occur every year according to publications on snakebite and the World Health Organization (WHO) mortality database in 2008 (14). Snakebites caused by the families of Viperidae and Elapidae are particularly dangerous to humans. Not all the snakebites are fatal, yet they may result in the following conditions: permanent physical disability, including limb amputation; chronic ulceration; osteomyelitis with malignant transformation; chronic renal failure; chronic pituitary-adrenal insufficiency; Address correspondence to: Mieko Suzuki Division of Biomolecular Chemistry, Graduate School of Natural Sciences, Nagoya City University, Mizuho, Nagoya, 467-8501, Japan Tel: +81-52-872-5851, Fax: +81-52-872-5857 E-mail: m.suzuki@nsc.nagoya-cu.ac.jp To avoid confusion in terms of taxonomy, the following names were used in this paper:

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Molecular cloning, characterization and evolution of the gene encoding a new group of short‐chain α‐neurotoxins in an Australian elapid, Pseudonaja textilis

Cited by 39 publications

References 26 publications

Cloning and characterization of the pseudonajatoxin b precursor

Cloning and characterization of the pseudonajatoxin b precursor

Common evolution of waprin and kunitz-like toxin families in Australian venomous snakes

Molecular diversity in venom proteins of the Russell's viper (Daboia russellii russellii) and the Indian cobra (Naja naja) in Sri Lanka

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