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Jean-yves Exposito - One of the best experts on this subject based on the ideXlab platform.
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The Fibrillar Collagen family.
International Journal of Molecular Sciences, 2010Co-Authors: Jean-yves Exposito, Caroline Cluzel, Ulrich Valcourt, Claire LethiasAbstract:Collagens, or more precisely Collagen-based extracellular matrices, are often considered as a metazoan hallmark. Among the Collagens, Fibrillar Collagens are present from sponges to humans, and are involved in the formation of the well-known striated fibrils. In this review we discuss the different steps in the evolution of this protein family, from the formation of an ancestral Fibrillar Collagen gene to the formation of different clades. Genomic data from the choanoflagellate (sister group of Metazoa) Monosiga brevicollis, and from diploblast animals, have suggested that the formation of an ancestral α chain occurred before the metazoan radiation. Phylogenetic studies have suggested an early emergence of the three clades that were first described in mammals. Hence the duplication events leading to the formation of the A, B and C clades occurred before the eumetazoan radiation. Another important event has been the two rounds of “whole genome duplication” leading to the amplification of Fibrillar Collagen gene numbers, and the importance of this diversification in developmental processes. We will also discuss some other aspects of Fibrillar Collagen evolution such as the development of the molecular mechanisms involved in the formation of proCollagen molecules and of striated fibrils.
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demosponge and sea anemone Fibrillar Collagen diversity reveals the early emergence of a c clades and the maintenance of the modular structure of type v xi Collagens from sponge to human
Journal of Biological Chemistry, 2008Co-Authors: Jean-yves Exposito, Caroline Cluzel, Ulrich Valcourt, Claire Larroux, Claire Lethias, Bernhard M DegnanAbstract:Collagens are often considered a metazoan hallmark, with the fibril-forming Fibrillar Collagens present from sponges to human. From evolutionary studies, three Fibrillar Collagen clades (named A, B, and C) have been defined and shown to be present in mammals, whereas the emergence of the A and B clades predates the protostome/deuterostome split. Moreover, several C clade Fibrillar Collagen chains are present in some invertebrate deuterostome genomes but not in protostomes whose genomes have been sequenced. The newly sequenced genomes of the choanoflagellate Monosiga brevicollis, the demosponge Amphimedon queenslandica, and the cnidarians Hydra magnipapillata (Hydra) and Nematostella vectensis (sea anemone) allow us to have a better understanding of the origin and evolution of Fibrillar Collagens. Analysis of these genomes suggests that an ancestral Fibrillar Collagen gene arose at the dawn of the Metazoa, before the divergence of sponge and eumetazoan lineages. The duplication events leading to the formation of the three Fibrillar Collagen clades (A, B, and C) occurred before the eumetazoan radiation. Interestingly, only the B clade Fibrillar Collagens preserved their characteristic modular structure from sponge to human. This observation is compatible with the suggested primordial function of type V/XI Fibrillar Collagens in the initiation of the formation of the Collagen fibrils.
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Invertebrate data predict an early emergence of vertebrate Fibrillar Collagen clades and an anti-incest model.
Journal of Biological Chemistry, 2004Co-Authors: Abdel Aouacheria, Caroline Cluzel, Claire Lethias, Robert Garrone, Manolo Gouy, Jean-yves ExpositoAbstract:Fibrillar Collagens are involved in the formation of striated fibrils and are present from the first multicel-lular animals, sponges, to humans. Recently, a new evolutionary model for Fibrillar Collagens has been suggested (Boot-Handford, R. P., Tuckwell, D. S., Plumb, D. A., Farrington Rock, C., and Poulsom, R. (2003) J. Biol. Chem. 278, 31067–31077). In this model, a rare genomic event leads to the formation of the founder vertebrate Fibrillar Collagen gene prior to the early vertebrate ge-nome duplications and the radiation of the vertebrate Fibrillar Collagen clades (A, B, and C). Here, we present the modular structure of the Fibrillar Collagen chains present in different invertebrates from the protostome Anopheles gambiae to the chordate Ciona intestinalis. From their modular structure and the use of a triple helix instead of C-propeptide sequences in phylogenetic analyses, we were able to show that the divergence of A and B clades arose early during evolution because chains related to these clades are present in protos-tomes. Moreover, the event leading to the divergence of B and C clades from a founder gene arose before the appearance of vertebrates; altogether these data contradict the Boot-Handford model. Moreover, they indicate that all the key steps required for the formation of fibrils of variable structure and functionality arose step by step during invertebrate evolution.
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Sea urchin Fibrillar Collagen 2α chain participates in heterotrimeric molecules of (1α)22α stoichiometry
Matrix Biology, 2000Co-Authors: Caroline Cluzel, Claire Lethias, Robert Garrone, Jean-yves ExpositoAbstract:Abstract In sea urchin, two Fibrillar Collagen chains (α1 and α2) have been characterized by molecular biology while two biochemically detected chains (α1 and α2) have been reported. Here, to determine the relationship between these results, Western-blotting and Edman degradation sequencing of the amino-termini of pepsinized sea urchin Fibrillar Collagen chains were performed. The data demonstrate that the 2α chain corresponds to the α2 chain and is involved in the formation of heterotrimeric molecules [(1α) 2 2α].
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Cloning of an annelid Fibrillar-Collagen gene and phylogenetic analysis of vertebrate and invertebrate Collagens
European Journal of Biochemistry, 1997Co-Authors: Fx Sicot, Jean-yves Exposito, Robert Garrone, M. Masselot, Jean S. Deutsch, Françoise GaillAbstract:Arenicola marina possesses cuticular and interstitial Collagens, which are mostly synthesised by its epidermis. A cDNA library was constructed from the body wall. This annelid cDNA library was screened with a sea-urchin-Collagen cDNA probe, and several overlapping clones were isolated. Nucleotide sequencing of these clones revealed an open reading frame of 2052 nucleotides. The translation product exhibits a triple helical domain of 138 Gly-Xaa-Yaa repeats followed by a 269-residue-long C-terminal non-Collagenous domain (C-propeptide). The triple helical domain exhibits an imperfection that has been previously described in a peptide produced by cyanogen bromide digestion (CNBr peptide) of A. marina interstitial Collagen. This imperfection occurs at the same place in the interstitial Collagen of the vestimen-tiferan Riftia pachyptila. This identifies the clone as coding for the C-terminal part of a Fibrillar Collagen chain. It was called Fam1α, for Fibrillar Collagen 1α chain of A. marina. The non-Collagenous domain possesses a structure similar to carboxy-terminal propeptides of Fibrillar pro-α chains. Only six conserved cysteine residues are observed in A. marina compared with seven or eight in all other known C-propeptides. This provides information on the importance of disulfide bonds in C-propeptide interactions and in the Collagen-assembly process. Phylogenetic studies indicate that the Fibrillar Collagen 1α chain of A. marina is homologous to the R. pachyptila interstitial Collagen and that the Fam1α gene evolved independently from the other a-chain genes. Complementary analyses indicate that the vertebrate Fibrillar Collagen family is composed of two monophyletic subgroups with a specific position of the Collagen type-V chains.
Michael R. Zile - One of the best experts on this subject based on the ideXlab platform.
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Age-dependent alterations in Fibrillar Collagen content and myocardial diastolic function: role of SPARC in post-synthetic proCollagen processing
American Journal of Physiology-heart and Circulatory Physiology, 2009Co-Authors: Amy D. Bradshaw, Catalin F. Baicu, Tyler J. Rentz, An O. Van Laer, D. Dirk Bonnema, Michael R. ZileAbstract:Advanced age, independent of concurrent cardiovascular disease, can be associated with increased extracellular matrix (ECM) Fibrillar Collagen content and abnormal diastolic function. However, the ...
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pressure overload induced alterations in Fibrillar Collagen content and myocardial diastolic function role of secreted protein acidic and rich in cysteine sparc in post synthetic proCollagen processing
Circulation, 2009Co-Authors: Amy D. Bradshaw, Catalin F. Baicu, Tyler J. Rentz, An O. Van Laer, Janet M. Boggs, John M. Lacy, Michael R. ZileAbstract:Background— Chronic pressure overload causes myocardial hypertrophy, increased Fibrillar Collagen content, and abnormal diastolic function. We hypothesized that one determinant of these pressure overload–induced changes is the extracellular processing of newly synthesized proCollagen into mature Collagen fibrils. We further hypothesized that secreted protein acidic and rich in cysteine (SPARC) plays a key role in post–synthetic proCollagen processing in normal and pressure-overloaded myocardium. Methods and Results— To determine whether pressure overload–induced changes in Collagen content and diastolic function are affected by the absence of SPARC, age-matched wild-type (WT) and SPARC-null mice underwent either transverse aortic constriction (TAC) for 4 weeks or served as nonoperated controls. Left ventricular (LV) Collagen content was measured histologically by Collagen volume fraction, Collagen composition was measured by hydroxyproline assay as soluble Collagen (1 mol/L NaCl extractable) versus insoluble Collagen (mature cross-linked Collagen), and Collagen morphological structure was examined by scanning electron microscopy. SPARC expression was measured by immunoblot. LV, myocardial, and cardiomyocyte structure and function were assessed by echocardiographic, papillary muscle, and isolated cardiomyocyte studies. In WT mice, TAC increased LV mass, SPARC expression, myocardial diastolic stiffness, Fibrillar Collagen content, and soluble and insoluble Collagen. In SPARC-null mice, TAC increased LV mass to an extent similar to WT mice. In addition, in SPARC-null mice, TAC increased Fibrillar Collagen content, albeit significantly less than that seen in WT TAC mice. Furthermore, the proportion of LV Collagen that was insoluble was less in the SPARC-null TAC mice (86±2%) than in WT TAC mice (99±2%, P P P Conclusions— The absence of SPARC reduced pressure overload–induced alterations in extracellular matrix Fibrillar Collagen and diastolic function. These data support the hypothesis that SPARC plays a key role in post–synthetic proCollagen processing and the development of mature cross-linked Collagen fibrils in normal and pressure-overloaded myocardium.
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Pressure-Overload Induced Alterations in Fibrillar Collagen Content and Myocardial Diastolic Function: Role of SPARC in Post-Synthetic ProCollagen Processing
Circulation, 2008Co-Authors: Amy D. Bradshaw, Catalin F. Baicu, Tyler J. Rentz, An O. Van Laer, Janet M. Boggs, John M. Lacy, Michael R. ZileAbstract:Background Chronic pressure-overload (PO) causes myocardial hypertrophy, increased Fibrillar Collagen content, and abnormal diastolic function. We hypothesized that one determinant of these PO-induced changes is the extracellular processing of newly synthesized proCollagen into mature Collagen fibrils. We further hypothesized that SPARC (Secreted Protein Acidic and Rich in Cysteine) plays a key role in post-synthetic proCollagen processing in normal and PO myocardium.
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Inhibition of Collagen cross-linking: effects on Fibrillar Collagen and ventricular diastolic function
American Journal of Physiology-Heart and Circulatory Physiology, 1995Co-Authors: S. Kato, Francis G. Spinale, Ryuhei Tanaka, W. Johnson, G. Cooper, Michael R. ZileAbstract:The Fibrillar Collagen network is postulated to be a primary determinant of left ventricular diastolic stiffness. This hypothesis was tested by examining the structural and physiological effects of...
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Inhibition of Collagen cross-linking: effects on Fibrillar Collagen and ventricular diastolic function.
The American journal of physiology, 1995Co-Authors: S. Kato, Francis G. Spinale, Ryuhei Tanaka, W. Johnson, G. Cooper, Michael R. ZileAbstract:The Fibrillar Collagen network is postulated to be a primary determinant of left ventricular diastolic stiffness. This hypothesis was tested by examining the structural and physiological effects of a reduction in Fibrillar Collagen content and cross-linking in the intact left ventricle. Collagen cross-linking was inhibited by treating five normal adult pigs with beta-aminopropionitrile (BAPN; 10 g/day po) for 6 wk; five normal untreated pigs served as controls. Left ventricular volume, mass, and function were determined by simultaneous echocardiography and catheterization. Chamber stiffness, defined by pressure vs. volume data, and myocardial stiffness, defined by stress vs. dimension data, were determined from variably loaded beats during dextran infusion. Collagen distribution (% area) and integrity (% confluence) were determined by light microscopy. Collagen content was measured by hydroxyproline assay, and Collagen cross-linking was measured by salt extraction. BAPN decreased Collagen distribution (% area decreased from 12 +/- 1% in control to 7 +/- 1% in BAPN, P < 0.05), Collagen integrity (% confluence decreased from 8 +/- 1% in control to 4 +/- 1% in BAPN, P < 0.05), Collagen content (from 36 +/- 2 mg/g dry wt in control to 27 +/- 2 mg/g dry wt in BAPN, P < 0.05), and Collagen cross-linking (extractable Collagen increased from 21 +/- 2% in control to 28 +/- 2% in BAPN, P < 0.05). BAPN decreased chamber stiffness (0.13 +/- 0.02 in control to 0.06 +/- 0.01 in BAPN, P < 0.05) and myocardial stiffness (10.4 +/- 0.5 in control to 6.6 +/- 0.5 in BAPN, P < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)
Caroline Cluzel - One of the best experts on this subject based on the ideXlab platform.
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The Fibrillar Collagen family.
International Journal of Molecular Sciences, 2010Co-Authors: Jean-yves Exposito, Caroline Cluzel, Ulrich Valcourt, Claire LethiasAbstract:Collagens, or more precisely Collagen-based extracellular matrices, are often considered as a metazoan hallmark. Among the Collagens, Fibrillar Collagens are present from sponges to humans, and are involved in the formation of the well-known striated fibrils. In this review we discuss the different steps in the evolution of this protein family, from the formation of an ancestral Fibrillar Collagen gene to the formation of different clades. Genomic data from the choanoflagellate (sister group of Metazoa) Monosiga brevicollis, and from diploblast animals, have suggested that the formation of an ancestral α chain occurred before the metazoan radiation. Phylogenetic studies have suggested an early emergence of the three clades that were first described in mammals. Hence the duplication events leading to the formation of the A, B and C clades occurred before the eumetazoan radiation. Another important event has been the two rounds of “whole genome duplication” leading to the amplification of Fibrillar Collagen gene numbers, and the importance of this diversification in developmental processes. We will also discuss some other aspects of Fibrillar Collagen evolution such as the development of the molecular mechanisms involved in the formation of proCollagen molecules and of striated fibrils.
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demosponge and sea anemone Fibrillar Collagen diversity reveals the early emergence of a c clades and the maintenance of the modular structure of type v xi Collagens from sponge to human
Journal of Biological Chemistry, 2008Co-Authors: Jean-yves Exposito, Caroline Cluzel, Ulrich Valcourt, Claire Larroux, Claire Lethias, Bernhard M DegnanAbstract:Collagens are often considered a metazoan hallmark, with the fibril-forming Fibrillar Collagens present from sponges to human. From evolutionary studies, three Fibrillar Collagen clades (named A, B, and C) have been defined and shown to be present in mammals, whereas the emergence of the A and B clades predates the protostome/deuterostome split. Moreover, several C clade Fibrillar Collagen chains are present in some invertebrate deuterostome genomes but not in protostomes whose genomes have been sequenced. The newly sequenced genomes of the choanoflagellate Monosiga brevicollis, the demosponge Amphimedon queenslandica, and the cnidarians Hydra magnipapillata (Hydra) and Nematostella vectensis (sea anemone) allow us to have a better understanding of the origin and evolution of Fibrillar Collagens. Analysis of these genomes suggests that an ancestral Fibrillar Collagen gene arose at the dawn of the Metazoa, before the divergence of sponge and eumetazoan lineages. The duplication events leading to the formation of the three Fibrillar Collagen clades (A, B, and C) occurred before the eumetazoan radiation. Interestingly, only the B clade Fibrillar Collagens preserved their characteristic modular structure from sponge to human. This observation is compatible with the suggested primordial function of type V/XI Fibrillar Collagens in the initiation of the formation of the Collagen fibrils.
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Invertebrate data predict an early emergence of vertebrate Fibrillar Collagen clades and an anti-incest model.
Journal of Biological Chemistry, 2004Co-Authors: Abdel Aouacheria, Caroline Cluzel, Claire Lethias, Robert Garrone, Manolo Gouy, Jean-yves ExpositoAbstract:Fibrillar Collagens are involved in the formation of striated fibrils and are present from the first multicel-lular animals, sponges, to humans. Recently, a new evolutionary model for Fibrillar Collagens has been suggested (Boot-Handford, R. P., Tuckwell, D. S., Plumb, D. A., Farrington Rock, C., and Poulsom, R. (2003) J. Biol. Chem. 278, 31067–31077). In this model, a rare genomic event leads to the formation of the founder vertebrate Fibrillar Collagen gene prior to the early vertebrate ge-nome duplications and the radiation of the vertebrate Fibrillar Collagen clades (A, B, and C). Here, we present the modular structure of the Fibrillar Collagen chains present in different invertebrates from the protostome Anopheles gambiae to the chordate Ciona intestinalis. From their modular structure and the use of a triple helix instead of C-propeptide sequences in phylogenetic analyses, we were able to show that the divergence of A and B clades arose early during evolution because chains related to these clades are present in protos-tomes. Moreover, the event leading to the divergence of B and C clades from a founder gene arose before the appearance of vertebrates; altogether these data contradict the Boot-Handford model. Moreover, they indicate that all the key steps required for the formation of fibrils of variable structure and functionality arose step by step during invertebrate evolution.
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Sea urchin Fibrillar Collagen 2α chain participates in heterotrimeric molecules of (1α)22α stoichiometry
Matrix Biology, 2000Co-Authors: Caroline Cluzel, Claire Lethias, Robert Garrone, Jean-yves ExpositoAbstract:Abstract In sea urchin, two Fibrillar Collagen chains (α1 and α2) have been characterized by molecular biology while two biochemically detected chains (α1 and α2) have been reported. Here, to determine the relationship between these results, Western-blotting and Edman degradation sequencing of the amino-termini of pepsinized sea urchin Fibrillar Collagen chains were performed. The data demonstrate that the 2α chain corresponds to the α2 chain and is involved in the formation of heterotrimeric molecules [(1α) 2 2α].
Yves A Declerck - One of the best experts on this subject based on the ideXlab platform.
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The cyclin-dependent kinase inhibitors p15INK4B and p21CIP1 are critical regulators of Fibrillar Collagen-induced tumor cell cycle arrest.
Journal of Biological Chemistry, 2007Co-Authors: Steven J. Wall, Zhi-duan Zhong, Yves A DeclerckAbstract:Abstract The extracellular matrix is a crucial component in determining cell fate. Fibrillar Collagen in its native form inhibits cell proliferation, whereas in its monomeric form it stimulates proliferation. The observation of elevated levels of p27KIP1 in cells plated in the presence of Fibrillar Collagen has led to the assumption that this kinase inhibitor was responsible for cell cycle arrest on Fibrillar Collagen. Here we provide evidence that p15INK4b, rather than p27KIP1, is the cyclin-dependent kinase inhibitor responsible for G0/G1 arrest of human melanoma cells grown on Fibrillar Collagen. Additionally, we demonstrate that Fibrillar Collagen can also arrest cells at the G2 phase, which is mediated in part by p21CIP1. Our data, in addition to identifying cyclin-dependent kinase inhibitors important in cell cycle arrest mediated by Fibrillar Collagen, demonstrate the complexity of cell cycle regulation and indicate that modulating a single cyclin-dependent kinase inhibitor does not disrupt cell proliferation in the presence of Fibrillar Collagen.
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The Cyclin-dependent Kinase Inhibitors p15 INK4B and p21 CIP1 Are Critical Regulators of Fibrillar Collagen-induced Tumor
2007Co-Authors: Steven J. Wall, Zhi-duan Zhong, Yves A DeclerckAbstract:.Ourdata,inadditiontoidentifyingcyclin-dependentkinaseinhibitorsimportantincellcyclearrestmediated by Fibrillar Collagen, demonstrate the complexity ofcellcycleregulationandindicatethatmodulatingasinglecyclin-dependentkinaseinhibitordoesnotdisruptcellproliferationinthe presence of Fibrillar Collagen.
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discoidin domain receptor 2 mediates tumor cell cycle arrest induced by Fibrillar Collagen
Journal of Biological Chemistry, 2005Co-Authors: Steven J. Wall, Zena Werb, Erica Werner, Yves A DeclerckAbstract:Abstract During malignant invasion tumor cells establish contact with extracellular matrix proteins, including Fibrillar Collagen. In addition to providing a physical barrier against invasion, Fibrillar Collagen also restricts cell proliferation. It has been assumed that the growth regulatory activity of Fibrillar Collagen is the result of an indirect restrictive effect on cell spreading and cytoskeletal organization. Here we provide evidence for a direct inhibitory effect of Fibrillar Collagen on proliferation of human melanoma and fibrosarcoma cells that involves activation of the tyrosine kinase discoidin domain receptor 2 and is independent of effects on cell spreading. Cells plated in the presence of Fibrillar Collagen were growth arrested in the G0/G1 phase of the cell cycle. However treatment with the tyrosine kinase inhibitor genistein, down-regulation of discoidin domain receptor 2, or Collagen deglycosylation that prevents discoidin domain receptor 2 activation allowed cells to enter the cell cycle in the presence of Fibrillar Collagen without a requirement for spreading and actin organization. Our data provide evidence for a novel direct mechanism by which cell contact with Fibrillar Collagen restricts proliferation.
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Contact with Fibrillar Collagen inhibits melanoma cell proliferation by up-regulating p27KIP1.
Proceedings of the National Academy of Sciences, 2000Co-Authors: Patrick Henriet, Zhi-duan Zhong, Peter C. Brooks, Kenneth I. Weinberg, Yves A DeclerckAbstract:It is known that the extracellular matrix regulates normal cell proliferation, and it is assumed that anchorage-independent malignant cells escape this regulatory function. Here we demonstrate that human M24met melanoma cells remain responsive to growth regulatory signals that result from contact with type I Collagen and that the effect on proliferation depends on the physical structure of the Collagen. On polymerized Fibrillar Collagen, M24met cells are growth arrested at the G1/S checkpoint and maintain high levels of p27KIP1 mRNA and protein. In contrast, on nonFibrillar (denatured) Collagen, the cells enter the cell cycle, and p27KIP1 is down-regulated. These growth regulatory effects involve contact between type I Collagen and the Collagen-binding integrin α2β1, which appears restricted in the presence of Fibrillar Collagen. Thus melanoma cells remain sensitive to negative growth regulatory signals originating from Fibrillar Collagen, and the proteolytic degradation of fibrils is a mechanism allowing tumor cells to escape these restrictive signals.
Claire Lethias - One of the best experts on this subject based on the ideXlab platform.
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The Fibrillar Collagen family.
International Journal of Molecular Sciences, 2010Co-Authors: Jean-yves Exposito, Caroline Cluzel, Ulrich Valcourt, Claire LethiasAbstract:Collagens, or more precisely Collagen-based extracellular matrices, are often considered as a metazoan hallmark. Among the Collagens, Fibrillar Collagens are present from sponges to humans, and are involved in the formation of the well-known striated fibrils. In this review we discuss the different steps in the evolution of this protein family, from the formation of an ancestral Fibrillar Collagen gene to the formation of different clades. Genomic data from the choanoflagellate (sister group of Metazoa) Monosiga brevicollis, and from diploblast animals, have suggested that the formation of an ancestral α chain occurred before the metazoan radiation. Phylogenetic studies have suggested an early emergence of the three clades that were first described in mammals. Hence the duplication events leading to the formation of the A, B and C clades occurred before the eumetazoan radiation. Another important event has been the two rounds of “whole genome duplication” leading to the amplification of Fibrillar Collagen gene numbers, and the importance of this diversification in developmental processes. We will also discuss some other aspects of Fibrillar Collagen evolution such as the development of the molecular mechanisms involved in the formation of proCollagen molecules and of striated fibrils.
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demosponge and sea anemone Fibrillar Collagen diversity reveals the early emergence of a c clades and the maintenance of the modular structure of type v xi Collagens from sponge to human
Journal of Biological Chemistry, 2008Co-Authors: Jean-yves Exposito, Caroline Cluzel, Ulrich Valcourt, Claire Larroux, Claire Lethias, Bernhard M DegnanAbstract:Collagens are often considered a metazoan hallmark, with the fibril-forming Fibrillar Collagens present from sponges to human. From evolutionary studies, three Fibrillar Collagen clades (named A, B, and C) have been defined and shown to be present in mammals, whereas the emergence of the A and B clades predates the protostome/deuterostome split. Moreover, several C clade Fibrillar Collagen chains are present in some invertebrate deuterostome genomes but not in protostomes whose genomes have been sequenced. The newly sequenced genomes of the choanoflagellate Monosiga brevicollis, the demosponge Amphimedon queenslandica, and the cnidarians Hydra magnipapillata (Hydra) and Nematostella vectensis (sea anemone) allow us to have a better understanding of the origin and evolution of Fibrillar Collagens. Analysis of these genomes suggests that an ancestral Fibrillar Collagen gene arose at the dawn of the Metazoa, before the divergence of sponge and eumetazoan lineages. The duplication events leading to the formation of the three Fibrillar Collagen clades (A, B, and C) occurred before the eumetazoan radiation. Interestingly, only the B clade Fibrillar Collagens preserved their characteristic modular structure from sponge to human. This observation is compatible with the suggested primordial function of type V/XI Fibrillar Collagens in the initiation of the formation of the Collagen fibrils.
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Invertebrate data predict an early emergence of vertebrate Fibrillar Collagen clades and an anti-incest model.
Journal of Biological Chemistry, 2004Co-Authors: Abdel Aouacheria, Caroline Cluzel, Claire Lethias, Robert Garrone, Manolo Gouy, Jean-yves ExpositoAbstract:Fibrillar Collagens are involved in the formation of striated fibrils and are present from the first multicel-lular animals, sponges, to humans. Recently, a new evolutionary model for Fibrillar Collagens has been suggested (Boot-Handford, R. P., Tuckwell, D. S., Plumb, D. A., Farrington Rock, C., and Poulsom, R. (2003) J. Biol. Chem. 278, 31067–31077). In this model, a rare genomic event leads to the formation of the founder vertebrate Fibrillar Collagen gene prior to the early vertebrate ge-nome duplications and the radiation of the vertebrate Fibrillar Collagen clades (A, B, and C). Here, we present the modular structure of the Fibrillar Collagen chains present in different invertebrates from the protostome Anopheles gambiae to the chordate Ciona intestinalis. From their modular structure and the use of a triple helix instead of C-propeptide sequences in phylogenetic analyses, we were able to show that the divergence of A and B clades arose early during evolution because chains related to these clades are present in protos-tomes. Moreover, the event leading to the divergence of B and C clades from a founder gene arose before the appearance of vertebrates; altogether these data contradict the Boot-Handford model. Moreover, they indicate that all the key steps required for the formation of fibrils of variable structure and functionality arose step by step during invertebrate evolution.
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Sea urchin Fibrillar Collagen 2α chain participates in heterotrimeric molecules of (1α)22α stoichiometry
Matrix Biology, 2000Co-Authors: Caroline Cluzel, Claire Lethias, Robert Garrone, Jean-yves ExpositoAbstract:Abstract In sea urchin, two Fibrillar Collagen chains (α1 and α2) have been characterized by molecular biology while two biochemically detected chains (α1 and α2) have been reported. Here, to determine the relationship between these results, Western-blotting and Edman degradation sequencing of the amino-termini of pepsinized sea urchin Fibrillar Collagen chains were performed. The data demonstrate that the 2α chain corresponds to the α2 chain and is involved in the formation of heterotrimeric molecules [(1α) 2 2α].