Processing of the Matricellular Protein Hevin in Mouse Brain Is Dependent on ADAMTS4

Matt S Weaver,Gail Workman,Marina Cardo-Vila,Wadih Arap,Renata Pasqualini,E Helene Sage

doi:10.1074/jbc.m109.070318

Abstract

The matricellular SPARC family member hevin (SPARC-like 1/SPARCL-1/SC1/Mast9) contributes to neural development and alters tumor progression in a range of mammalian models. The distribution of hevin in mouse tissues was reexamined with a novel monoclonal antibody that discriminates between hevin and its ortholog SPARC. We now report proteolysis of hevin in many tissues, with the most extensive processing in the brain. We demonstrate a cleavage site within the hevin sequence for the neural tissue proteinase ADAMTS4. Digestion of hevin by ADAMTS4 in vitro produced fragments similar to those present in brain lysates. Monoclonal antibodies revealed a SPARC-like fragment generated from hevin that was co-localized with ADAMTS4 in vivo. We show that proteolysis of hevin by ADAMTS4 in the mouse cerebellum is important for the normal development of this tissue. In conclusion, we have identified the fragmentation of hevin by ADAMTS4 in the mouse brain and propose that this specific proteolysis is integral to cell morphology and extracellular matrix deposition in the developing brain.

Highlights

Grants GM40711 and CA109559. □S The on-line version of this article contains supplemental Figs. 1 and 2. 1 To whom correspondence should be addressed: 1201 9th Ave., Seattle, WA throughout the murine brain [4, 5]
We demonstrated that the 12-54 monoclonal antibody detects the SPARC-like fragment (SLF) by immunoblot, whereas 12-155 detects only the full-length hevin (Fig. 3, panels B–D)
Hevin and SPARC exhibit significant protein similarity, tissue distribution, and apparent function, considerably less is known about the mechanisms controlling the distribution of hevin and its role in vivo

Summary

Introduction

Grants GM40711 and CA109559. □S The on-line version of this article (available at http://www.jbc.org) contains supplemental Figs. 1 and 2. 1 To whom correspondence should be addressed: 1201 9th Ave., Seattle, WA throughout the murine brain [4, 5]. Monoclonal rat antibody 12-155 served as the Routine sample analysis and identification of astrocytes/micronegative control antibody because of its reaction with hevin but glial cells were performed on serial sections of brain tissue with not with the SLF. We demonstrated that the 12-54 monoclonal antibody detects the SLF (but not the C-terminal peptide) by immunoblot, whereas 12-155 detects only the full-length hevin (Fig. 3, panels B–D).

Results

Conclusion