Perlecan and Basement Membrane-Chondroitin Sulfate Proteoglycan (Bamacan) Are Two Basement Membrane Chondroitin/Dermatan Sulfate Proteoglycans in the Engelbreth-Holm-Swarm Tumor Matrix (*)
- From the (1)Department of Cell Biology Cell Adhesion & Matrix Research Center, University of Alabama at Birmingham, Birmingham, Alabama 35294 and
- (2)Collaborative Biomedical Products, Becton Dickinson Company, Bedford, Massachusetts 01730
- § To whom correspondence should be addressed: Dept. of Cell Biology, University of Alabama at Birmingham, VH 201C, University Blvd., Birmingham, AL 35294-0019. Tel.: 205-934-2626; Fax: 205-975-9956.
Abstract
The presence of proteoglycans bearing galactosaminoglycan chains has been reported, but none has been identified previously in the matrix of the Engelbreth-Holm-Swarm tumor, which is a source of several basement membrane components. This tumor matrix contains perlecan, a large, low buoyant density heparan sulfate proteoglycan, widespread in many basement membranes and connective tissues. We now identify two distinct proteoglycan species from this tumor source, which are substituted with galactosaminoglycans and which show basement membrane localization by immunohistochemistry. One species is perlecan but, in addition to being present as a heparan sulfate proteoglycan, it is also present as a hybrid molecule, with dermatan sulfate chains. A minor population of perlecan apparently lacks heparan sulfate chains totally, and some of this is substituted with chondroitin sulfate. The second species is immunologically related to basement membrane-chondroitin sulfate proteoglycan (BM-CSPG) and bears chondroitin sulfate chains. No BM-CSPG was detectable which was substituted with heparan sulfate chains. A combination of immunological and molecular approaches, including cDNA cloning, showed that perlecan and BM-CSPG are distinct in core protein structure. Both are, however, basement membrane components, although there are tissue-specific differences in their distribution.
Footnotes
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↵** Supported by a fellowship from the Helen Keller Eye Research Foundation.
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↵* This work was supported by National Institutes of Health Grant AR36457 (to J. R. C.). The costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore by hereby marked “advertisement” in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.
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↵1 The abbreviations used are:
- EHS
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Engelbreth-Holm-Swarm
- BM-CSPG
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basement membrane-chondroitin sulfate proteoglycan
- HSPG
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heparan sulfate proteoglycan
- DSPG
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dermatan sulfate proteoglycan
- PBS
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phosphate-buffered saline
- PAGE
-
polyacrylamide gel electrophoresis
- kb
-
kilobase(s).
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- Received August 31, 1995.
- Revision received January 23, 1996.
- © 1996 by The American Society for Biochemistry and Molecular Biology, Inc.
