A unique covalent bond in basement membrane is a primordial innovation for tissue evolution

Proc Natl Acad Sci U S A. 2014 Jan 7;111(1):331-6. doi: 10.1073/pnas.1318499111. Epub 2013 Dec 16.


Basement membrane, a specialized ECM that underlies polarized epithelium of eumetazoans, provides signaling cues that regulate cell behavior and function in tissue genesis and homeostasis. A collagen IV scaffold, a major component, is essential for tissues and dysfunctional in several diseases. Studies of bovine and Drosophila tissues reveal that the scaffold is stabilized by sulfilimine chemical bonds (S = N) that covalently cross-link methionine and hydroxylysine residues at the interface of adjoining triple helical protomers. Peroxidasin, a heme peroxidase embedded in the basement membrane, produces hypohalous acid intermediates that oxidize methionine, forming the sulfilimine cross-link. We explored whether the sulfilimine cross-link is a fundamental requirement in the genesis and evolution of epithelial tissues by determining its occurrence and evolutionary origin in Eumetazoa and its essentiality in zebrafish development; 31 species, spanning 11 major phyla, were investigated for the occurrence of the sulfilimine cross-link by electrophoresis, MS, and multiple sequence alignment of de novo transcriptome and available genomic data for collagen IV and peroxidasin. The results show that the cross-link is conserved throughout Eumetazoa and arose at the divergence of Porifera and Cnidaria over 500 Mya. Also, peroxidasin, the enzyme that forms the bond, is evolutionarily conserved throughout Metazoa. Morpholino knockdown of peroxidasin in zebrafish revealed that the cross-link is essential for organogenesis. Collectively, our findings establish that the triad-a collagen IV scaffold with sulfilimine cross-links, peroxidasin, and hypohalous acids-is a primordial innovation of the ECM essential for organogenesis and tissue evolution.

Publication types

  • Research Support, American Recovery and Reinvestment Act
  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Basement Membrane / metabolism*
  • Biological Evolution*
  • Collagen Type IV / chemistry
  • Cross-Linking Reagents / chemistry
  • Drosophila melanogaster
  • Extracellular Matrix / metabolism
  • Extracellular Matrix Proteins / chemistry
  • Heme / chemistry
  • Imines / chemistry*
  • Mass Spectrometry
  • Molecular Sequence Data
  • Peptides / chemistry
  • Peroxidase / chemistry
  • Peroxidases / chemistry
  • Protein Structure, Tertiary
  • Sequence Analysis, RNA
  • Sequence Homology, Amino Acid
  • Sulfur Compounds / chemistry*
  • Zebrafish


  • Collagen Type IV
  • Cross-Linking Reagents
  • Extracellular Matrix Proteins
  • Imines
  • Peptides
  • Sulfur Compounds
  • sulfilimine
  • Heme
  • Peroxidases
  • peroxidasin
  • Peroxidase

Associated data

  • GENBANK/GAMX01000001
  • GENBANK/GAMX01000002
  • GENBANK/GAMY01000001
  • GENBANK/GAMY01000002
  • GENBANK/GAMZ01000002
  • GENBANK/GANA01000001
  • GENBANK/GANA01000002
  • GENBANK/GANB01000001
  • GENBANK/GANB01000002
  • GENBANK/GANC01000002
  • GENBANK/GAND01000001
  • GENBANK/GAND01000002