Isolation and cellular localization of the decorin endocytosis receptor.
The small dermatan sulfate proteoglycans decorin and biglycan are efficiently internalized by a variety of cells of mesenchymal origin. This process is modulated, at least under tissue culture conditions, by cell surface-associated heparan sulfate proteoglycans. Receptor proteins of 51 and 26 kDa, respectively, bind to leucine-rich repeat structures of the core proteins of the small proteoglycans but also to highly sulfated domains of heparan sulfate. The 51 kDa protein was purified from rat brain tissue by subcellular fractionation, heparin affinity chromatography and subsequent SDS-PAGE, and was used for raising a polyclonal antiserum. Affinity-purified antibodies also recognize the 26 kDa protein and a few other low molecular weight proteins, suggesting that these proteins represent proteolytic degradation products of the 51 kDa receptor. By confocal laser microscopy, it could be demonstrated that the affinity-purified antibody reacted at 0 degree C with a protein that became internalized and was transported to a perinuclear compartment during 15 min of incubation at 37 degrees C. These findings provide direct evidence that the receptor protein(s) are internalized together with the ligand and reach an endosomal compartment where further sorting can occur.
Hausser
H
H
Institute of Physiological Chemistry and Pathobiochemistry, University of Münster, Germany.
Wedekind
P
P
Sperber
T
T
Peters
R
R
Hasilik
A
A
Kresse
H
H
D000818:Animals; D002458:Cell Fractionation; D002462:Cell Membrane / Q000737:chemistry; D002478:Cells, Cultured; D002846:Chromatography, Affinity; D058575:Decorin; D004591:Electrophoresis, Polyacrylamide Gel; D004705:Endocytosis; D016326:Extracellular Matrix Proteins; D005455:Fluorescent Antibody Technique; D006801:Humans; D011509:Proteoglycans / Q000378:metabolism*; D051381:Rats; D017978:Receptors, Growth Factor / Q000032:analysis / Q000276:immunology / Q000302:isolation & purification / Q000378:metabolism*
C546878:DCN protein, human; C546880:Dcn protein, rat; D058575:Decorin; D016326:Extracellular Matrix Proteins; D011509:Proteoglycans; D017978:Receptors, Growth Factor; C069389:decorin receptor