Elsevier

Toxicon

Volume 42, Issue 8, December 2003, Pages 841-854
Toxicon

Molecular evolution of myotoxic phospholipases A2 from snake venom

https://doi.org/10.1016/j.toxicon.2003.11.003Get rights and content

Abstract

After two decades of study, we draw the conclusion that venom-gland phospholipase A2 (PLA2) isozymes, including PLA2 myotoxins of Crotalinae snakes, have evolved in an accelerated manner to acquire their diverse physiological activities. In this review, we describe how accelerated evolution of venom PLA2 isozymes was discovered. This type of evolution is fundamental for other venom isozyme systems. Accelerated evolution of venom PLA2 isozyme genes is due to rapid change in exons, but not in introns and the flanking regions, being completely opposite to the case of the ordinary isozyme genes. The molecular mechanism by which proper base substitutions had occurred in the particular sites of venom isozyme genes is a puzzle to be solved in future studies. It should be noted that accelerated evolution occurred until the isozymes had acquired their particular function and, since then, they have evolved with less frequent mutation, possibly for functional conservation. We also found that interisland mutations occurred in venom PLA2 isozymes. The relationships between mutation and its driving force are speculative and the real mechanism remains a mystery.

Section snippets

Preface

Although snake venoms contain a number of bioactive proteins, phospholipase A2 (PLA2) isoforms constitute major toxic components. It is well known that snake venom PLA2s exhibit a variety of physiological activities in addition to intrinsic lipolytic action. From analysis of the cDNAs and genes encoding snake venom PLA2s, it became evident that they have evolved in an accelerated manner. Such accelerated evolution has rarely been known in general (ordinary) isozymes. Now it is thought that

Classification and amino acid sequences of snake venom PLA2s

PLA2 [EC 3.1.1.4] catalyzes the hydrolysis of the 2-acyl ester bond of 3-sn-phosphoglycerides with the requirement of Ca2+to produce 3-sn-lysophosphoglycerides and fatty acids. The amino acid sequences of over 200 PLA2s, in which about 170 are from snake venoms, had been determined up to 1997 (Danse et al., 1997). At present its number is still increasing. Most of them are classified into groups I and II based on the mode of disulfide pairings (Dufton and Hider, 1983). Group I PLA2s are found

Crystal structure of snake venom PLA2s

After the crystal structure of bovine pancreatic [Asp49]PLA2, which belongs to group I, was established by Dijkstra et al. (1981), those of group I [Asp49]PLA2s from the venoms of Naja naja atra (Scott et al., 1990), N. n. naja (Fremont et al., 1993), and Notechis s. scutatus (Westerlund et al., 1992), and of group II [Asp49]PLA2s from the venoms of Crotalus atrox (Brunie et al., 1985), Agkistrodon halys blomhoffii (Tomoo et al., 1994), T. flavoviridis (Suzuki et al., 1995), A. halys pallas (

Diverse physiological activities of snake venom PLA2s

Snake venom PLA2 isozymes are well known to exhibit a variety of physiological activities such as hemolysis (Kihara et al., 1992), myotoxicity (Gutierrez and Lomonte, 1997, Gopalakrishnakone et al., 1997), neurotoxicity (Bon, 1997, Gubensek et al., 1997, Fletcher and Rosenberg, 1997), anticoagulant activity (Evans and Kini, 1997), edema-inducing activity (Vishwanath et al., 1987, Wang and Teng, 1990, Liu et al., 1991, Tan et al., 1991, Yamaguchi et al., 2001), cardiotoxicity (Fletcher et al.,

Structures of the cDNAs and genes encoding venom PLA2 isozymes

Five cDNAs encoding T. flavoviridis (Tokunoshima) venom-gland PLA2 isozymes, PLA2, [Thr38]PLA2, PL-X′, BPI and BPII, were cloned and sequenced (Oda et al., 1990, Ogawa et al., 1992). It was clearly indicated by Northern blot analysis with these cDNAs and their 5′ or 3′ untranslated regions (UTRs) as probes that the mRNAs coding for these PLA2 isozymes are expressed only in the venom gland but not in other tissues such as heart, lung, liver, pancreas, kidneys, gall bladder, testis and ovaries (

Accelerated evolution of Crotalinae snake venom PLA2 isozyme genes

The evolutionary significance was noted for the nucleotide sequences of Crotalinae snake (T. flavoviridis, T. gramineus and T. okinavensis) venom PLA2 isozyme genes. Mathematical analysis was conducted for relevant pairs of PLA2 isozyme genes. The numbers of nucleotide substitutions per site (KN) for the noncoding regions, the numbers of nucleotide substitutions per synonymous site (KS), and the numbers of nucleotide substitutions per nonsynonymous site (KA) for the protein-coding regions were

Mechanism of accelerated evolution of snake venom PLA2 isozyme genes

A concept of accelerated evolution was led by several characteristics of the venom PLA2 isozyme genes: (1) the protein-coding regions, except for the signal sequence domain, are much more variable than the noncoding regions including introns, (2) the rates of nonsynonymous substitution are close to or greater than those of synonymous substitution in the protein-coding regions, and (3) the gene products exhibit diverse physiological activities. Two possibilities are considered for accelerated

Evolutionary relationships of Viperidae venom PLA2 isozymes

Phylogenetic trees were constructed for the nucleotide sequences of 11 Viperidae group II PLA2 cDNAs (Ogawa et al., 1995) according to the one-parameter method (Jukes and Cantor, 1969) and to the neighbor-joining algorithm (Saitou and Nei, 1987). A evolutionary tree constructed from the combined sequences of the 5′ and 3′ UTRs and the signal peptide-coding region is shown in Fig. 5. This tree shows that there are two groups, Crotalinae PLA2s and Viperinae PLA2s, which are evidently divided.

Interisland evolution of venom-gland PLA2 isozymes of T. flavoviridis snakes

T. flavoviridis snakes inhabit the southwestern islands of Japan: Amami-Oshima, Tokunoshima and Okinawa. Amami-Oshima is the northernmost and Tokunoshima island is 30 km south of Amami-Oshima. Okinawa island is located a further 120 km south of Tokunoshima island. These islands are thought to have been separated by eustacy (change in sea level) in the orogenic stage 1–2 million years ago (Hoshino, 1975). Since then, ancestral T. flavoviridis species in the former Okinawa continent were

References (97)

  • D.R Holland et al.

    The crystal structure of a lysine49 phospholipase A2 from the venom of the cottonmouth snake at 2.0 Å resolution

    J. Biol. Chem.

    (1990)
  • T.R John et al.

    Genomic sequences encoding the acidic and basic subunits of Mojave toxin: unusually high sequence identity of non-coding regions

    Gene

    (1994)
  • I.I Kaiser et al.

    The amino acid sequence of a myotoxic phospholipase A2 from the venom of Bothrops asper

    Arch. Biochem. Biophys.

    (1990)
  • D Kordis et al.

    Adaptive evolution of animal toxin multigene families

    Gene

    (2000)
  • R.M Kramer et al.

    Structure and properties of a human non-pancreatic phospholipase A2

    J. Biol. Chem.

    (1989)
  • K Kubo et al.

    Primary structures of human protein kinase C beta I and beta II differ only in their C-terminal sequences

    FEBS Lett.

    (1987)
  • C Kusunoki et al.

    Structure of genomic DNA for rat platelet phospholipase A2

    Biochim. Biophys. Acta

    (1990)
  • C.S Liu et al.

    The amino acid sequence and properties of an edema-inducing Lys-49 phospholipase A2 homolog from the venom of Trimeresurus mucrosquamatus

    Biochim. Biophys. Acta

    (1991)
  • J.M Maraganore et al.

    The lysine-49 phospholipase A2 from the venom of Agkistrodon piscivorus piscivorus. Relation of structure and function to other phospholipases A2

    J. Biol. Chem.

    (1986)
  • J.M Maraganore et al.

    A new class of phospholipase A2 with lysine in place of aspartate 49. Functional consequences for calcium and substrate binding

    J. Biol. Chem.

    (1984)
  • K Nakashima et al.

    Structures of genes encoding TATA box-binding proteins from Trimeresurus gramineus and T. flavoviridis snakes

    Gene

    (1995)
  • I Nobuhisa et al.

    Accelerated evolution of Trimeresurus okinavensis venom gland phospholipase A2 isozyme-encoding genes

    Gene

    (1996)
  • N Oda et al.

    Amino acid sequence of a phospholipase A2 from the venom of Trimeresurus gramineus (green habu snake)

    Toxicon

    (1991)
  • T Ohta et al.

    Gene conversion generates hypervariability at the variable regions of kallikreins and their inhibitors

    Mol. Phylogenet. Evol.

    (1992)
  • M Orita et al.

    Rapid and sensitive detection of point mutations and DNA polymorphisms using the polymerase chain reaction

    Genomics

    (1989)
  • J Pungercar et al.

    Cloning and nucleotide sequence of a cDNA encoding ammodytoxin A, the most toxic phospholipase A2 from the venom of long-nosed viper (Vipera ammodytes)

    Toxicon

    (1991)
  • A Randolph et al.

    Crotalus atrox phospholipase A2: amino acid sequence and studies on the functions of the N-terminal region

    J. Biol. Chem.

    (1982)
  • D.L Scott et al.

    Crystallographic and biochemical studies of the (inactive) Lys-49 phospholipase A2 from the venom of Agkistrodon piscivorus piscivorus

    J. Biol. Chem.

    (1992)
  • J.J Seilhamer et al.

    Cloning and recombinant expression of phospholipase A2 present in rheumatoid arthritic synovial fluid

    J. Biol. Chem.

    (1989)
  • A Tani et al.

    Characterization, primary structure and molecular evolution of anticoagulant protein from Agkistrodon actus venom

    Toxicon

    (2002)
  • J.P Wang et al.

    Comparison of the enzymatic and edema-producing activities of two venom phospholipase A2 enzymes

    Eur. J. Pharmacol.

    (1990)
  • Y.M Wang et al.

    Molecular cloning and deduced primary structures of acidic and basic phospholipases A2 from the venom of Deinagkistrodon acutus

    Toxicon

    (1996)
  • X.Q Wang et al.

    Crystal structure of an acidic phospholipase A2 from the venom of Agkistrodon halys pallas at 2.0 Å resolution

    J. Mol. Biol.

    (1996)
  • Y Yamaguchi et al.

    Characterization, amino acid sequence and evolution of edema-inducing, basic phospholipase A2 from Trimeresurus flavoviridis venom

    Toxicon

    (2001)
  • K Yoshizumi et al.

    Purification and amino acid sequence of basic protein I, a lysine-49-phospholipase A2 with low activity, from the venom of Trimeresurus flavoviridis (habu snake)

    Toxicon

    (1990)
  • R.K Arni et al.

    Structure of a calcium-independent phospholipase-like myotoxic protein from Bothrops asper venom

    Acta Crystallogr.

    (1995)
  • C Bon

    Multicomponent neurotoxic phospholipases A2

  • R Breathnach et al.

    Related ovalbumin gene: evidence for a leader sequence in mRNA and DNA sequences at the exon–intron boundaries

    Proc. Natl Acad. Sci. USA

    (1978)
  • L.N Chen et al.

    Isolation and characterization of a toxic phospholipase A2 from the venom of the Taiwan habu (Trimeresurus mucrosquamatus)

    Biotech. Appl. Biochem.

    (1994)
  • T Chijiwa et al.

    Regional evolution of venom-gland phospholipase A2 isoenzymes of Trimeresurus flavoviridis snakes in the southwestern islands of Japan

    Biochem. J.

    (2000)
  • T Chijiwa et al.

    Interisland mutation of a novel phospholipase A2 from Trimeresurus flavoviridis venom and evolution of Crotalinae group II phospholipases A2

    J. Mol. Evol.

    (2003)
  • T Chijiwa et al.

    Interisland evolution of Trimeresurus flavoviridis venom phospholipase A2 isozymes

    J. Mol. Evol.

    (2003)
  • J.M Danse et al.

    Molecular biology of snake venom phospholipases A2

  • C Diaz et al.

    Purification and characterization of myotoxin IV, a phospholipase A2 variant, from Bothrops asper snake venom

    J. Natural Toxins

    (1995)
  • B.W Dijkstra et al.

    Structure of bovine pancreatic phospholipase A2 at 1.7 Å resolution

    J. Mol. Biol.

    (1981)
  • M.J Dufton et al.

    Classification of phospholipases A2 according to sequence. Evolutionary and pharmacological implications

    Eur. J. Biochem.

    (1983)
  • H.J Evans et al.

    The anticoagulant effects of snake venom phospholipases A2

  • E.A.M Fleer et al.

    The primary structure of bovine pancreatic phospholipase A2

    Eur. J. Biochem.

    (1978)
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