Identification of a novel member of the pentraxin family in Xenopus laevis.
Pentraxins are a family of acute phase reactants. Two family members, C-reactive protein (CRP) and serum amyloid P component (SAP), are known in a range of mammalian species. CRP and SAP are both about 200 residues long, and arose from a gene duplication event, apparently before the divergence of the mammalian orders. To elucidate the origins of mammalian pentraxins, we have searched for pentraxin-coding genes in the amphibian Xenopus laevis. We have identified a gene determining a protein (XL-PXN1) which is about twice the size expected: the XL-PXN1 gene appears to be a fusion between regions encoding an amino-terminal peptide of unknown function and a carboxy-terminal pentraxin. The pentraxin domain is more divergent from CRP and SAP than they are from each other: it provides an outgroup for analysis of the evolution of mammalian pentraxins and confirms that putative CRP and SAP proteins partly characterized in non-vertebrate species cannot be true homologues of the mammalian proteins.
Seery
L T
LT
Department of Genetics, Trinity College, University of Dublin, Ireland.
Schoenberg
D R
DR
Barbaux
S
S
Sharp
P M
PM
Whitehead
A S
AS
D000209:Acute-Phase Proteins / Q000235:genetics*; D000595:Amino Acid Sequence; D000818:Animals; D002097:C-Reactive Protein / Q000235:genetics; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000302:isolation & purification; D006801:Humans; D008322:Mammals / Q000235:genetics; D008969:Molecular Sequence Data; D005810:Multigene Family; D009838:Oligodeoxyribonucleotides; D010802:Phylogeny; D016133:Polymerase Chain Reaction; D017386:Sequence Homology, Amino Acid; D000683:Serum Amyloid P-Component / Q000235:genetics; D014982:Xenopus laevis / Q000235:genetics*
D000209:Acute-Phase Proteins; D018076:DNA, Complementary; D009838:Oligodeoxyribonucleotides; D000683:Serum Amyloid P-Component; D002097:C-Reactive Protein