Combined extracellular matrix cross-linking activity of the peroxidase MLT-7 and the dual oxidase BLI-3 is critical for post-embryonic viability in Caenorhabditis elegans

Thein, M. C., Winter, A. D., Stepek, G., McCormack, G., Stapleton, G., Johnstone, I. L. and Page, A. P. (2009) Combined extracellular matrix cross-linking activity of the peroxidase MLT-7 and the dual oxidase BLI-3 is critical for post-embryonic viability in Caenorhabditis elegans. Journal of Biological Chemistry, 284(26), pp. 17549-17563. (doi: 10.1074/jbc.M900831200)

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Publisher's URL: http://dx.doi.org/10.1074/jbc.M900831200

Abstract

The nematode cuticle is a protective collagenous extracellular matrix that is modified, cross-linked, and processed by a number of key enzymes. This Ecdysozoan-specific structure is synthesized repeatedly and allows growth and development in a linked degradative and biosynthetic process known as molting. A targeted RNA interference screen using a cuticle collagen marker has been employed to identify components of the cuticle biosynthetic pathway. We have characterized an essential peroxidase, MoLT-7 (MLT-7), that is responsible for proper cuticle molting and re-synthesis. MLT-7 is an active, inhibitable peroxidase that is expressed in the cuticle-synthesizing hypodermis coincident with each larval molt. mlt-7 mutants show a range of body morphology defects, most notably molt, dumpy, and early larval stage arrest phenotypes that can all be complemented with a wild type copy of mlt-7. The cuticles of these mutants lacks di-tyrosine cross-links, becomes permeable to dye and accessible to tyrosine iodination, and have aberrant collagen protein expression patterns. Overexpression of MLT-7 causes mutant phenotypes further supporting its proposed enzymatic role. In combination with BLI-3, an H2O2-generating NADPH dual oxidase, MLT-7 is essential for post-embryonic development. Disruption of mlt-7, and particularly bli-3, via RNA interference also causes dramatic changes to the in vivo cross-linking patterns of the cuticle collagens DPY-13 and COL-12. This points toward a functionally cooperative relationship for these two hypodermally expressed proteins that is essential for collagen cross-linking and proper extracellular matrix formation.

Item Type:Articles
Status:Published
Refereed:Yes
Glasgow Author(s) Enlighten ID:Stapleton, Dr Genevieve and Johnstone, Professor Iain and McCormack, Ms Gillian and Page, Professor Tony and Stepek, Dr Gillian and Winter, Dr Alan
Authors: Thein, M. C., Winter, A. D., Stepek, G., McCormack, G., Stapleton, G., Johnstone, I. L., and Page, A. P.
Subjects:Q Science > QH Natural history > QH345 Biochemistry
College/School:College of Medical Veterinary and Life Sciences > School of Life Sciences
College of Medical Veterinary and Life Sciences > Institute of Infection Immunity and Inflammation
Journal Name:Journal of Biological Chemistry
Journal Abbr.:J Biol Chem.
Publisher:American Society for Biochemistry and Molecular Biology, Inc.
ISSN:0021-9258
ISSN (Online):1083-351X
Published Online:30 April 2009
Copyright Holders:Copyright © 2009 American Society for Biochemistry and Molecular Biology
First Published:First published in Journal of Biological Chemistry 284(26):17549-17563
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Project CodeAward NoProject NamePrincipal InvestigatorFunder's NameFunder RefLead Dept
393191A genetic analysis of the response to the presence of glycine substitution mutant collagen in C. elegansIain JohnstoneMedical Research Council (MRC)G0401202Life Sciences Biomolecular Science
229993The Molecular Enzymology of Collagen Assembly and Post-Translational Modification: a Nematode Model SystemAntony PageMedical Research Council (MRC)G117/476Infection Immunity and Inflammation Life Sciences