CD44 anchors the assembly of matrilysin/MMP-7 with heparin-binding epidermal growth factor precursor and ErbB4 and regulates female reproductive organ remodeling
- Molecular Pathology Unit, Massachusetts General Hospital, and Department of Pathology, Harvard Medical School, Boston, Massachusetts 02129, USA; 1Department of Biochemistry and Molecular Biology, University of Miami School of Medicine, Miami, Florida 33101, USA; 2Pfizer Central Research, Groton, Connecticut 06340, USA
Abstract
CD44 is a facultative proteoglycan implicated in cell adhesion and trafficking, as well as in tumor survival and progression. We demonstrate here that CD44 heparan sulfate proteoglycan (CD44HSPG) recruits proteolytically active matrix metalloproteinase 7 (matrilysin, MMP-7) and heparin-binding epidermal growth factor precursor (pro-HB-EGF) to form a complex on the surface of tumor cell lines, postpartum uterine and lactating mammary gland epithelium, and uterine smooth muscle. The HB-EGF precursor within this complex is processed by MMP-7, and the resulting mature HB-EGF engages and activates its receptor, ErbB4, leading to, among other events, cell survival. In CD44−/− mice, postpartum uterine involution is accelerated and maintenance of lactation is impaired. In both uterine and mammary epithelia of these mice, MMP-7 localization is altered and pro-HB-EGF processing as well as ErbB4 activation are decreased. Our observations provide a mechanism for the assembly and function of a cell surface complex composed of CD44HSPG, MMP 7, HB-EGF, and ErbB4 that may play an important role in the regulation of physiological tissue remodeling.
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Footnotes
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↵3 Corresponding author.
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E-MAIL stamenko{at}helix.mgh.harvard.edu; FAX (617)726-5684.
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Article and publication are at http://www.genesdev.org/cgi/doi/10.1101/gad.925702.
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- Received July 3, 2001.
- Accepted December 10, 2001.
- Cold Spring Harbor Laboratory Press