Complexes of matrilin-1 and biglycan or decorin connect collagen VI microfibrils to both collagen II and aggrecan.
Native supramolecular assemblies containing collagen VI microfibrils and associated extracellular matrix proteins were isolated from Swarm rat chondrosarcoma tissue. Their composition and spatial organization were characterized by electron microscopy and immunological detection of molecular constituents. The small leucine-rich repeat (LRR) proteoglycans biglycan and decorin were bound to the N-terminal region of collagen VI. Chondroadherin, another member of the LRR family, was identified both at the N and C termini of collagen VI. Matrilin-1, -3, and -4 were found in complexes with biglycan or decorin at the N terminus. The interactions between collagen VI, biglycan, decorin, and matrilin-1 were studied in detail and revealed a biglycan/matrilin-1 or decorin/matrilin-1 complex acting as a linkage between collagen VI microfibrils and aggrecan or alternatively collagen II. The complexes between matrilin-1 and biglycan or decorin were also reconstituted in vitro. Colocalization of collagen VI and the different ligands in the pericellular matrix of cultured chondrosarcoma cells supported the physiological relevance of the observed interactions in matrix assembly.
Wiberg
Charlotte
C
Department of Cell and Molecular Biology, University of Lund, BMC, S-221 84 Lund, Sweden.
Klatt
Andreas R
AR
Wagener
Raimund
R
Paulsson
Mats
M
Bateman
John F
JF
Heinegård
Dick
D
Mörgelin
Matthias
M
D053674:Aggrecans; D000818:Animals; D058578:Biglycan; D002478:Cells, Cultured; D019902:Chondrocytes / Q000737:chemistry; D024043:Collagen Type II / Q000737:chemistry*; D024142:Collagen Type VI / Q000737:chemistry*; D058575:Decorin; D005109:Extracellular Matrix / Q000737:chemistry; D016326:Extracellular Matrix Proteins / Q000737:chemistry*; D006023:Glycoproteins / Q000737:chemistry*; D037181:Lectins, C-Type; D000090263:Leucine-Rich Repeat Proteins; D064235:Matrilin Proteins; D020894:Microfibrils / Q000737:chemistry*; D008854:Microscopy, Electron; D011506:Proteins / Q000737:chemistry; D011509:Proteoglycans / Q000737:chemistry*; D051381:Rats
C508321:Acan protein, rat; D053674:Aggrecans; C546886:Bgn protein, rat; D058578:Biglycan; D024043:Collagen Type II; D024142:Collagen Type VI; C546880:Dcn protein, rat; D058575:Decorin; D016326:Extracellular Matrix Proteins; D006023:Glycoproteins; D037181:Lectins, C-Type; D000090263:Leucine-Rich Repeat Proteins; D064235:Matrilin Proteins; D011506:Proteins; D011509:Proteoglycans