Isolation and partial characterization of a cell-surface heparan sulfate proteoglycan from embryonic rat spinal cord.
Cell-surface heparan sulfate proteoglycans (HSPGs) are potential mediators of neuronal cell adhesion, spreading, and neurite outgrowth on various extra-cellular matrix molecules. One possible site of HSPG attachment is a heparin binding domain of fibronectin, which is present in the synthetic peptide FN-C/H II. In this study, HSPGs extracted from embryonic rat spinal cord by detergent were purified by ion-exchange chromatography, gel filtration, and affinity chromatography on an agarose column coupled with FN-C/H II conjugated to ovalbumin (OA). Heparitinase treatment of the iodinated HSPG fraction led to the appearance of a major protein core with a molecular size of 72 kDa, as determined by reducing SDS-PAGE. The intact proteoglycan has a molecular size of approximately 150-165 kDa, containing heparan sulfate glycosaminoglycan chains of about 10-15 kDa. Anti-HSPG antibodies recognized the 72 kDa core protein by immunoblotting, and stained the surface of spinal cord neurons, oligodendrocytes, and a subset of astrocytes. These results identify a cell-surface HSPG that may mediate neuron-substratum or neuron-glia interactions in embryonic central nervous system.
Department of Cell Biology, University of Minnesota, Minneapolis 55455.
J M
JM
Giuseppetti
J B
JB
McCarthy
P C
PC
Letourneau
D000595:Amino Acid Sequence; D000818:Animals; D001665:Binding Sites; D002448:Cell Adhesion; D002845:Chromatography / Q000379:methods; D005353:Fibronectins / Q000737:chemistry / Q000378:metabolism; D019812:Heparan Sulfate Proteoglycans; D006497:Heparan Sulfate / Q000737:chemistry / Q000276:immunology / Q000302:isolation & purification*; D008856:Microscopy, Fluorescence; D008969:Molecular Sequence Data; D008970:Molecular Weight; D009024:Morphogenesis; D009474:Neurons / Q000737:chemistry*; D010446:Peptide Fragments / Q000138:chemical synthesis / Q000378:metabolism; D011509:Proteoglycans / Q000737:chemistry / Q000276:immunology / Q000302:isolation & purification*; D051381:Rats; D017207:Rats, Sprague-Dawley; D017469:Receptors, Fibronectin / Q000378:metabolism*; D013116:Spinal Cord / Q000737:chemistry* / Q000196:embryology*
D005353:Fibronectins; D019812:Heparan Sulfate Proteoglycans; D006497:Heparan Sulfate; D010446:Peptide Fragments; D011509:Proteoglycans; D017469:Receptors, Fibronectin