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

Abstract

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.

Proprotein Convertase Processing Enhances Peroxidasin Activity to Reinforce Collagen IV

“…Expectedly, the peroxidasin-collagen IV-sulfilimine bond triad is conserved throughout the animal kingdom, where the evolution of basement membranes is thought to be a key step in the development of multicellular tissues. The multidomain structure of peroxidasin is mostly conserved in Bilateria, whereas there is a distinct lack of the C-terminal vWFC domain in Cnidaria (11). Interestingly, we find that a PC cleavage site between the catalytic and vWFC domains is predicted in nearly all Bilateria, adding further credence to the importance of this processing in regulation of Pxdn function (Fig.…”

“…Pxdn preferentially generates HOBr as a reactive intermediate to form sulfilimine cross-links in collagen IV, which represents the first known function for the element bromine (4,9). Given its critical function in the synthesis of basement membranes, it is no surprise that peroxidasin is found throughout the animal kingdom, whereas other animal heme peroxidases are restricted to vertebrates (10,11). In addition, unlike other members of the animal heme peroxidase family, Pxdn is a multidomain protein that contains a leucine-rich region followed by four immunoglobulin-like domains, the catalytic peroxidase domain, and a C terminal von Willebrand factor type C (vWFC) domain (7,12,13).…”

Multidomain Human Peroxidasin 1 Is a Highly Glycosylated and Stable Homotrimeric High Spin Ferric Peroxidase

“…Furthermore, it was shown that this unique covalent bond in basement membrane is a primordial innovation for tissue evolution (14). Moreover, very recently it could be demonstrated that bromide oxidation to hypobromous acid mediated by hsPxd01 is essential for the assembly of collagen IV scaffolds in tissue development and architecture (15).…”

‘Biogeneric’ developmental processes: drivers of major transitions in animal evolution

“…The appearance in certain metazoan lineages of the type IV collagen cross-linking enzyme peroxidasin was constitutive of the out-of-plane elasticity of epithelia, and consequently of morphogenesis [58]. Analogous acquisitions and transformations of ancient secreted proteins enabled the formation of the invasionreceptive and EMT-promoting ECMs conducive to a third germ layer.…”