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Wenye Tjong - One of the best experts on this subject based on the ideXlab platform.
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the role of the RGD Motif in cd97 adgre5 and emr2 adgre2 modulated tumor angiogenesis
Biochemical and Biophysical Research Communications, 2019Co-Authors: Wenye TjongAbstract:Abstract CD97/ADGRE5, an adhesion G protein-coupled receptor (aGPCR), is highly expressed in several tumor cell types. CD97 has been shown to modulate tumorigenesis in part by promoting HUVEC migration, invasion and angiogenesis through the interaction with integrin α5β1 via its ectodomain RGD Motif. In this study, we show that CD97 could induce angiogenesis via an alternative RGD-independent mechanism. Overexpression of CD97 with the wild-type or mutant RGD Motif in HT1080 cells led to up-regulated MMP-9 and induced angiogenesis as revealed by the in vitro endothelial cell tube formation assay and in ovo chick chorioallantoic membrane assay. By contrast, expression of EMR2/ADGRE2, the CD97-homologous aGPCR that contains a corresponding SGD sequence, fails to induce angiogenesis due to lower MMP-9 expression. Interestingly, a single change of the SGD to RGD sequence allowed EMR2 to up-regulate MMP-9 expression, leading to enhanced angiogenesis. MMP-9 was shown to promote the proliferation, migration, and invasion of HUVEC partly by modulating the levels of VEGF, PIGF, and bFGF. Finally, we showed that the MMP-9 expression was in turn modulated by N-cadherin that was up-regulated by CD97 and EMR2/RGD. Our results indicate that two homologous aGPCRs, CD97 and EMR2, modulate angiogenesis and HUVEC proliferation, migration, and invasion through N-cadherin-regulated MMP-9 expression by RGD-independent and -dependent mechanisms, respectively.
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The role of the RGD Motif in CD97/ADGRE5-and EMR2/ADGRE2-modulated tumor angiogenesis
Biochemical and biophysical research communications, 2019Co-Authors: Wenye Tjong, Hsi-hsien LinAbstract:Abstract CD97/ADGRE5, an adhesion G protein-coupled receptor (aGPCR), is highly expressed in several tumor cell types. CD97 has been shown to modulate tumorigenesis in part by promoting HUVEC migration, invasion and angiogenesis through the interaction with integrin α5β1 via its ectodomain RGD Motif. In this study, we show that CD97 could induce angiogenesis via an alternative RGD-independent mechanism. Overexpression of CD97 with the wild-type or mutant RGD Motif in HT1080 cells led to up-regulated MMP-9 and induced angiogenesis as revealed by the in vitro endothelial cell tube formation assay and in ovo chick chorioallantoic membrane assay. By contrast, expression of EMR2/ADGRE2, the CD97-homologous aGPCR that contains a corresponding SGD sequence, fails to induce angiogenesis due to lower MMP-9 expression. Interestingly, a single change of the SGD to RGD sequence allowed EMR2 to up-regulate MMP-9 expression, leading to enhanced angiogenesis. MMP-9 was shown to promote the proliferation, migration, and invasion of HUVEC partly by modulating the levels of VEGF, PIGF, and bFGF. Finally, we showed that the MMP-9 expression was in turn modulated by N-cadherin that was up-regulated by CD97 and EMR2/RGD. Our results indicate that two homologous aGPCRs, CD97 and EMR2, modulate angiogenesis and HUVEC proliferation, migration, and invasion through N-cadherin-regulated MMP-9 expression by RGD-independent and -dependent mechanisms, respectively.
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the RGD Motif is involved in cd97 adgre5 promoted cell adhesion and viability of ht1080 cells
Scientific Reports, 2019Co-Authors: Wenye TjongAbstract:CD97/ADGRE5 is an adhesion G protein-coupled receptor (aGPCR) involved in tumor cell adhesion, migration, angiogenesis, and apoptosis. CD97 has been shown previously to stimulate angiogenesis by interacting with integrins on endothelial cells via an Arginine-Glycine-Aspartic acid (RGD) Motif. In this report, the role of the RGD Motif in tumor cell adhesion and apoptosis was investigated using a previously-established HT1080 cell-based system. We found that the RGD Motif is critical in CD97-promoted cell adhesion, in part due to the up-regulation of αvβ5 and α2β1 integrins, and that CD97 mediates its anti-apoptotic effect in extrinsic apoptosis via RGD-dependent cell adhesion. In contrast, CD97-modulated anti-apoptotic effect in intrinsic apoptosis is mediated by RGD-independent, N-cadherin-induced homotypic cell aggregation. Hence, CD97 promotes tumorigenesis via RGD-dependent and -independent mechanisms.
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The RGD Motif is involved in CD97/ADGRE5-promoted cell adhesion and viability of HT1080 cells
Scientific Reports, 2019Co-Authors: Wenye TjongAbstract:CD97/ADGRE5 is an adhesion G protein-coupled receptor (aGPCR) involved in tumor cell adhesion, migration, angiogenesis, and apoptosis. CD97 has been shown previously to stimulate angiogenesis by interacting with integrins on endothelial cells via an Arginine-Glycine-Aspartic acid (RGD) Motif. In this report, the role of the RGD Motif in tumor cell adhesion and apoptosis was investigated using a previously-established HT1080 cell-based system. We found that the RGD Motif is critical in CD97-promoted cell adhesion, in part due to the up-regulation of αvβ5 and α2β1 integrins, and that CD97 mediates its anti-apoptotic effect in extrinsic apoptosis via RGD-dependent cell adhesion. In contrast, CD97-modulated anti-apoptotic effect in intrinsic apoptosis is mediated by RGD-independent, N-cadherin-induced homotypic cell aggregation. Hence, CD97 promotes tumorigenesis via RGD-dependent and -independent mechanisms.
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the RGD Motif is involved in cd97 adgre5 promoted cell adhesion and viability of ht1080 cells
Scientific Reports, 2019Co-Authors: Wenye TjongAbstract:CD97/ADGRE5 is an adhesion G protein-coupled receptor (aGPCR) involved in tumor cell adhesion, migration, angiogenesis, and apoptosis. CD97 has been shown previously to stimulate angiogenesis by interacting with integrins on endothelial cells via an Arginine-Glycine-Aspartic acid (RGD) Motif. In this report, the role of the RGD Motif in tumor cell adhesion and apoptosis was investigated using a previously-established HT1080 cell-based system. We found that the RGD Motif is critical in CD97-promoted cell adhesion, in part due to the up-regulation of αvβ5 and α2β1 integrins, and that CD97 mediates its anti-apoptotic effect in extrinsic apoptosis via RGD-dependent cell adhesion. In contrast, CD97-modulated anti-apoptotic effect in intrinsic apoptosis is mediated by RGD-independent, N-cadherin-induced homotypic cell aggregation. Hence, CD97 promotes tumorigenesis via RGD-dependent and -independent mechanisms.
Glyn Stanway - One of the best experts on this subject based on the ideXlab platform.
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Arginine-Glycine-Aspartic Acid Motif Is Critical for Human Parechovirus 1 Entry
Journal of virology, 2001Co-Authors: Yingmanee Boonyakiat, Pamela J. Hughes, Farideh Ghazi, Glyn StanwayAbstract:The human parechovirus 1 RGD Motif in VP1 was studied by mutagenesis. An RGD-to-RGE change gave only revertant viruses with a restored RGD, while deletion of GD was lethal and nonrevertable. Mutations at the +1 and +2 positions had some effect on growth properties and a +1 M-to-P change was lethal. These studies indicate that the RGD Motif plays a critical role in infectivity, presumably by interacting with integrins, and that downstream amino acids can have an influence on function.
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The Coxsackievirus A9 RGD Motif Is Not Essential for Virus Viability
Journal of virology, 1995Co-Authors: Pamela J. Hughes, C Horsnell, Timo Hyypiä, Glyn StanwayAbstract:An RGD (arginine-glycine-aspartic acid) Motif in coxsackievirus A9 has been implicated in internalization through an interaction with the integrin alpha v beta 3. We have produced a number of virus mutants, lacking the Motif, which have a small-plaque phenotype in LLC-Mk2 and A-Vero cells and are phenotypically normal in RD cells. Substitution of flanking amino acids also affected plaque size. The results suggest that interaction between the RGD Motif and alpha v beta 3 is not critical for virus viability in the cell lines tested and therefore that alternative regions of the CAV-9 capsid are involved in internalization.
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The nucleotide sequences of wild-type coxsackievirus A9 strains imply that an RGD Motif in VP1 is functionally significant
Journal of General Virology, 1992Co-Authors: Ki Ha Chang, Timo Hyypiä, Carol Day, Jackie Walker, Glyn StanwayAbstract:We have shown previously that, compared to other enteroviruses, the coxsackievirus A9 (CAV-9) prototype strain, Griggs, contains a C-terminal extension to the capsid protein VP1 and that within this extension there is an RGD (arginine-glycine-aspartic acid) Motif. To determine whether these features are found in other CAV-9 strains and therefore analyse whether they are likely to be functionally important, we have determined the nucleotide sequence of the appropriate region from five strains, isolated over a 25 year period. The results indicate that there is considerable diversity between the strains and there is little correlation between nucleotide sequence identity and date of isolation. All isolates exhibit the VP1 extension and although its amino acid sequence is otherwise variable, the RGD Motif is common to all. This conservation of sequence, within a region which can otherwise vary, implies that the RGD sequence must be functionally significant. The VP1 extension shows similarity to sequences found in foot-and-mouth-disease virus strains and to part of the precursor of the cellular protein, human transforming growth factor β, and the possible significance of these observations is discussed.
Horst Kessler - One of the best experts on this subject based on the ideXlab platform.
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The Cyclic Cystine Ladder of Theta-Defensins as a Stable, Bifunctional Scaffold: A Proof-of-Concept Study Using the Integrin-Binding RGD Motif.
Chembiochem : a European journal of chemical biology, 2014Co-Authors: Anne C. Conibear, K. Johan Rosengren, Alexander Bochen, Petar Stupar, Conan K. Wang, Horst KesslerAbstract:Peptides have the specificity and size required to target the protein-protein interactions involved in many diseases. Some cyclic peptides have been utilised as scaffolds for peptide drugs because of their stability; however, other cyclic peptide scaffolds remain to be explored. theta-Defensins are cyclic peptides from mammals; they are characterised by a cyclic cystine ladder Motif and have low haemolytic and cytotoxic activity. Here we demonstrate the potential of the cyclic cystine ladder as a scaffold for peptide drug design by introducing the integrin-binding Arg-Gly-Asp (RGD) Motif into the theta-defensin RTD-1. The most active analogue had an IC50 of 18 nm for the alpha(v)beta(3) integrin as well as high serum stability, thus demonstrating that a desired bioactivity can be imparted to the cyclic cystine ladder. This study highlights how theta-defensins can provide a stable and conformationally restrained scaffold for bioactive epitopes in a beta-strand or turn conformation. Furthermore, the symmetry of the cyclic cystine ladder presents the opportunity to design peptides with dual bioactive epitopes to increase activity and specificity.
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The Cyclic Cystine Ladder of Theta-Defensins as a Stable, Bifunctional Scaffold: A Proof-of-Concept Study Using the Integrin-Binding RGD Motif.
Chembiochem : a European journal of chemical biology, 2014Co-Authors: Anne C. Conibear, Horst Kessler, K. Johan Rosengren, Alexander Bochen, Petar Stupar, Conan K. Wang, David J. CraikAbstract:Peptides have the specificity and size required to target the protein-protein interactions involved in many diseases. Some cyclic peptides have been utilised as scaffolds for peptide drugs because of their stability; however, other cyclic peptide scaffolds remain to be explored. θ-Defensins are cyclic peptides from mammals; they are characterised by a cyclic cystine ladder Motif and have low haemolytic and cytotoxic activity. Here we demonstrate the potential of the cyclic cystine ladder as a scaffold for peptide drug design by introducing the integrin-binding Arg-Gly-Asp (RGD) Motif into the θ-defensin RTD-1. The most active analogue had an IC50 of 18 nM for the αv β3 integrin as well as high serum stability, thus demonstrating that a desired bioactivity can be imparted to the cyclic cystine ladder. This study highlights how θ-defensins can provide a stable and conformationally restrained scaffold for bioactive epitopes in a β-strand or turn conformation. Furthermore, the symmetry of the cyclic cystine ladder presents the opportunity to design peptides with dual bioactive epitopes to increase activity and specificity.
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the RGD Motif in fibronectin is essential for development but dispensable for fibril assembly
Journal of Cell Biology, 2007Co-Authors: Seiichiro Takahashi, Michael Leiss, Tomoo Ohashi, Tomoe Kitao, Dominik Heckmann, Horst Kessler, Alexander Pfeifer, Markus Moser, Junichi Takagi, Harold P EricksonAbstract:Fibronectin (FN) is secreted as a disulfide-bonded FN dimer. Each subunit contains three types of repeating modules: FN-I, FN-II, and FN-III. The interactions of α5β1 or αv integrins with the RGD Motif of FN-III repeat 10 (FN-III10) are considered an essential step in the assembly of FN fibrils. To test this hypothesis in vivo, we replaced the RGD Motif with the inactive RGE in mice. FN-RGE homozygous embryos die at embryonic day 10 with shortened posterior trunk, absent tail bud–derived somites, and severe vascular defects resembling the phenotype of α5 integrin–deficient mice. Surprisingly, the absence of a functional RGD Motif in FN did not compromise assembly of an FN matrix in mutant embryos or on mutant cells. Matrix assembly assays and solid-phase binding assays reveal that αvβ3 integrin assembles FN-RGE by binding an isoDGR Motif in FN-I5, which is generated by the nonenzymatic rearrangement of asparagines (N) into an iso-aspartate (iso-D). Our findings demonstrate that FN contains a novel Motif for integrin binding and fibril formation whose activity is controlled by amino acid modification.
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the RGD Motif in fibronectin is essential for development but dispensable for fibril assembly
Journal of Cell Biology, 2007Co-Authors: Seiichiro Takahashi, Michael Leiss, Tomoo Ohashi, Tomoe Kitao, Dominik Heckmann, Horst Kessler, Alexander Pfeifer, Markus Moser, Junichi Takagi, Harold P EricksonAbstract:Fibronectin (FN) is secreted as a disulfide-bonded FN dimer. Each subunit contains three types of repeating modules: FN-I, FN-II, and FN-III. The interactions of alpha5beta1 or alphav integrins with the RGD Motif of FN-III repeat 10 (FN-III10) are considered an essential step in the assembly of FN fibrils. To test this hypothesis in vivo, we replaced the RGD Motif with the inactive RGE in mice. FN-RGE homozygous embryos die at embryonic day 10 with shortened posterior trunk, absent tail bud-derived somites, and severe vascular defects resembling the phenotype of alpha5 integrin-deficient mice. Surprisingly, the absence of a functional RGD Motif in FN did not compromise assembly of an FN matrix in mutant embryos or on mutant cells. Matrix assembly assays and solid-phase binding assays reveal that alphavbeta3 integrin assembles FN-RGE by binding an isoDGR Motif in FN-I5, which is generated by the nonenzymatic rearrangement of asparagines (N) into an iso-aspartate (iso-D). Our findings demonstrate that FN contains a novel Motif for integrin binding and fibril formation whose activity is controlled by amino acid modification.
Woei Jer Chuang - One of the best experts on this subject based on the ideXlab platform.
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Effect of P to A Mutation of the N-Terminal Residue Adjacent to the RGD Motif on Rhodostomin: Importance of Dynamics in Integrin Recognition
PloS one, 2012Co-Authors: Jia Hau Shiu, Chiu Yueh Chen, Yi-chun Chen, Yao Tsung Chang, Yung Sheng Chang, Chun Hao Huang, Woei Jer ChuangAbstract:Rhodostomin (Rho) is an RGD protein that specifically inhibits integrins. We found that Rho mutants with the P48A mutation 4.4–11.5 times more actively inhibited integrin α5β1. Structural analysis showed that they have a similar 3D conformation for the RGD loop. Docking analysis also showed no difference between their interactions with integrin α5β1. However, the backbone dynamics of RGD residues were different. The values of the R2 relaxation parameter for Rho residues R49 and D51 were 39% and 54% higher than those of the P48A mutant, which caused differences in S2, Rex, and τe. The S2 values of the P48A mutant residues R49, G50, and D51 were 29%, 14%, and 28% lower than those of Rho. The Rex values of Rho residues R49 and D51 were 0.91 s−1 and 1.42 s−1; however, no Rex was found for those of the P48A mutant. The τe values of Rho residues R49 and D51 were 9.5 and 5.1 times lower than those of P48A mutant. Mutational study showed that integrin α5β1 prefers its ligands to contain (G/A)RGD but not PRGD sequences for binding. These results demonstrate that the N-terminal proline residue adjacent to the RGD Motif affect its function and dynamics, which suggests that the dynamic properties of the RGD Motif may be important in Rho's interaction with integrin α5β1.
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Effect of D to E mutation of the RGD Motif in rhodostomin on its activity, structure, and dynamics: importance of the interactions between the D residue and integrin.
Proteins, 2009Co-Authors: Chiu Yueh Chen, Jia Hau Shiu, Yi-chun Chen, Yen Chin Chen, Yu-chen Liu, Yao Husn Hsieh, Wen Yih Jeng, Ming Jer Tang, Woei Jer ChuangAbstract:Rhodostomin (Rho) is a snake venom protein containing an RGD Motif that specifically inhibits the integrin-binding function. Rho produced in Pichia pastoris inhibits platelet aggregation with a K(I) of 78 nM as potent as native Rho. In contrast, its D51E mutant inhibits platelet aggregation with a K(I) of 49 muM. Structural analysis of Rho and its D51E mutant showed that they have the same tertiary fold with three two-stranded antiparallel beta-sheets. There are no structural backbone differences between the RG[D/E] loop which extends outward from the protein core and the RG[D/E] sequence at its apex in a four-residue RG[D/E]M type I turn. Two minor differences between Rho and its D51E mutant were only found from their backbone dynamics and 3D structures. The R(2) value of E51 is 13% higher than that of the D51 residue. A difference in the charge separation of 1.76 A was found between the sidechains of positive (R49) and negative residues (D51 or E51).The docking of Rho into integrin alphavbeta3 showed that the backbone amide and carbonyl groups of the D51 residue of Rho were formed hydrogen bonds with the integrin residues R216 and R214, respectively. In contrast, these hydrogen bonds were absent in the D51E mutant-integrin complex. Our findings suggest that the interactions between both the sidechain and backbone of the D residue of RGD-containing ligands and integrin are important for their binding.
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Solution structure of γ‐bungarotoxin: The functional significance of amino acid residues flanking the RGD Motif in integrin binding
Proteins, 2004Co-Authors: Jia Hau Shiu, Chiu Yueh Chen, Yi-chun Chen, Long Sen Chang, Yen Chin Chen, Yu-chen Liu, Woei Jer ChuangAbstract:Gamma-bungarotoxin, a snake venom protein isolated from Bungarus multicinctus, contains 68 amino acids, including 10 cysteine residues and a TAVRGDGP sequence at positions 30-37. The solution structure of gamma-bungarotoxin has been determined by nuclear magnetic resonance (NMR) spectroscopy. The structure is similar to that of the short-chain neurotoxins that contain three loops extending from a disulfide-bridged core. The tripeptide Arg-Gly-Asp (RGD) sequence is located at the apex of the flexible loop and is similar to that of other RGD-containing proteins. However, gamma-bungarotoxin only inhibits platelet aggregations with an IC50 of 34 microM. To understand its weak activity in inhibiting platelet aggregation, we mutated the RGD loop sequences of rhodostomin, a potent platelet aggregation inhibitor, from RIPRGDMP to TAVRGDGP, resulting in a 196-fold decrease in activity. In addition, the average Calpha-to-Calpha distance between R33 and G36 of gamma-bungarotoxin is 6.02 A, i.e., shorter than that of other RGD-containing proteins that range from 6.55 to 7.46 A. These results suggested that the amino acid residues flanking the RGD Motif might control the width of the RGD loop. This structural difference may be responsible for its decrease in platelet aggregation inhibition compared with other RGD-containing proteins.
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solution structure of γ bungarotoxin the functional significance of amino acid residues flanking the RGD Motif in integrin binding
Proteins, 2004Co-Authors: Jia Hau Shiu, Chiu Yueh Chen, Yi-chun Chen, Long Sen Chang, Yen Chin Chen, Yu-chen Liu, Woei Jer ChuangAbstract:Gamma-bungarotoxin, a snake venom protein isolated from Bungarus multicinctus, contains 68 amino acids, including 10 cysteine residues and a TAVRGDGP sequence at positions 30-37. The solution structure of gamma-bungarotoxin has been determined by nuclear magnetic resonance (NMR) spectroscopy. The structure is similar to that of the short-chain neurotoxins that contain three loops extending from a disulfide-bridged core. The tripeptide Arg-Gly-Asp (RGD) sequence is located at the apex of the flexible loop and is similar to that of other RGD-containing proteins. However, gamma-bungarotoxin only inhibits platelet aggregations with an IC50 of 34 microM. To understand its weak activity in inhibiting platelet aggregation, we mutated the RGD loop sequences of rhodostomin, a potent platelet aggregation inhibitor, from RIPRGDMP to TAVRGDGP, resulting in a 196-fold decrease in activity. In addition, the average Calpha-to-Calpha distance between R33 and G36 of gamma-bungarotoxin is 6.02 A, i.e., shorter than that of other RGD-containing proteins that range from 6.55 to 7.46 A. These results suggested that the amino acid residues flanking the RGD Motif might control the width of the RGD loop. This structural difference may be responsible for its decrease in platelet aggregation inhibition compared with other RGD-containing proteins.
Ki Ha Chang - One of the best experts on this subject based on the ideXlab platform.
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The nucleotide sequences of wild-type coxsackievirus A9 strains imply that an RGD Motif in VP1 is functionally significant
Journal of General Virology, 1992Co-Authors: Ki Ha Chang, Timo Hyypiä, Carol Day, Jackie Walker, Glyn StanwayAbstract:We have shown previously that, compared to other enteroviruses, the coxsackievirus A9 (CAV-9) prototype strain, Griggs, contains a C-terminal extension to the capsid protein VP1 and that within this extension there is an RGD (arginine-glycine-aspartic acid) Motif. To determine whether these features are found in other CAV-9 strains and therefore analyse whether they are likely to be functionally important, we have determined the nucleotide sequence of the appropriate region from five strains, isolated over a 25 year period. The results indicate that there is considerable diversity between the strains and there is little correlation between nucleotide sequence identity and date of isolation. All isolates exhibit the VP1 extension and although its amino acid sequence is otherwise variable, the RGD Motif is common to all. This conservation of sequence, within a region which can otherwise vary, implies that the RGD sequence must be functionally significant. The VP1 extension shows similarity to sequences found in foot-and-mouth-disease virus strains and to part of the precursor of the cellular protein, human transforming growth factor β, and the possible significance of these observations is discussed.
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The nucleotide sequences of wild-type coxsackievirus A9 strains imply that an RGD Motif in VP1 is functionally significant.
The Journal of general virology, 1992Co-Authors: Ki Ha Chang, Carol Day, Jackie Walker, T Hyypiä, G StanwayAbstract:We have shown previously that, compared to other enteroviruses, the coxsackievirus A9 (CAV-9) prototype strain, Griggs, contains a C-terminal extension to the capsid protein VP1 and that within this extension there is an RGD (arginine-glycine-aspartic acid) Motif. To determine whether these features are found in other CAV-9 strains and therefore analyse whether they are likely to be functionally important, we have determined the nucleotide sequence of the appropriate region from five strains, isolated over a 25 year period. The results indicate that there is considerable diversity between the strains and there is little correlation between nucleotide sequence identity and date of isolation. All isolates exhibit the VP1 extension and although its amino acid sequence is otherwise variable, the RGD Motif is common to all. This conservation of sequence, within a region which can otherwise vary, implies that the RGD sequence must be functionally significant. The VP1 extension shows similarity to sequences found in foot-and-mouth-disease virus strains and to part of the precursor of the cellular protein, human transforming growth factor beta, and the possible significance of these observations is discussed.
