Clusterin, an abundant serum factor, is a possible negative regulator of MT6-MMP/MMP-25 produced by neutrophils.

Journal article

MT6-MMP/MMP-25 is the latest member of the membrane-type matrix metalloproteinase (MT-MMP) subgroup in the MMP family and is expressed in neutrophils and some brain tumors. The proteolytic activity of MT6-MMP has been studied using recombinant catalytic fragments and shown to degrade several components of the extracellular matrix. However, the activity is possibly modulated further by the C-terminal hemopexin-like domain, because some MMPs are known to interact with other proteins through this domain. To explore the possible function of this domain, we purified a recombinant MT6-MMP with the hemopexin-like domain as a soluble form using a Madin-Darby canine kidney cell line as a producer. Mature and soluble MT6-MMP processed at the furin motif was purified as a 45-kDa protein together with a 46-kDa protein having a single cleavage in the hemopexin-like domain. Interestingly, 73- and 70-kDa proteins were co-purified with the soluble MT6-MMP by forming stable complexes. They were identified as clusterin, a major component of serum, by N-terminal amino acid sequencing. MT1-MMP that also has a hemopexin-like domain did not form a complex with clusterin. MT6-MMP forming a complex with clusterin was detected in human neutrophils as well. The enzyme activity of the soluble MT6-MMP was inactive in the clusterin complex. Purified clusterin was inhibitory against the activity of soluble MT6-MMP. On the other hand, it had no effect on the activities of MMP-2 and soluble MT1-MMP. Because clusterin is an abundant protein in the body fluid in tissues, it may act as a negative regulator of MT6-MMP in vivo.

Authors: Matsuda, A; Itoh, Y; Koshikawa, N; Akizawa, T; Yana, I

• Publication status: Published
• Journal: Journal of biological chemistry
• Volume: 278
• Issue: 38
• Pages: 36350-36357
• Publication date: 2003-09-01
• DOI: 10.1074/jbc.m301509200
• EISSN: 1083-351X
• ISSN: 0021-9258
• Language: English
• Keywords: Neutrophils; Electrophoresis, Polyacrylamide Gel; Precipitin Tests; Epitopes; Hydrogen-Ion Concentration; Plasmids; DNA, Complementary; Silver Staining; Genetic Vectors; Glycoproteins; Matrix Metalloproteinases, Membrane-Associated; COS Cells; Molecular Chaperones; Clusterin; Transfection; Protein Structure, Tertiary; Models, Genetic; Matrix Metalloproteinases; Cell Line; Blotting, Western; Catalytic Domain; Time Factors; Protein Binding; Chromatography, Gel; GPI-Linked Proteins; Humans; Furin; Gene Expression Regulation; Amino Acid Motifs; Cell Line, Tumor; Dogs; Kinetics; Recombinant Proteins; Animals; Dose-Response Relationship, Drug