Ligand-affinity cloning and structure of a cell surface heparan sulfate proteoglycan that binds basic fibroblast growth factor.
Expression cloning of cDNAs encoding a basic fibroblast growth factor (FGF) binding protein confirms previous hypotheses that this molecule is a cell-surface heparan sulfate proteoglycan. A cDNA library constructed from a hamster kidney cell line rich in FGF receptor activity was transfected into a human lymphoblastoid cell line. Clones expressing functional basic FGF binding proteins at their surfaces were enriched by panning on plastic dishes coated with human basic FGF. The amino acid sequence deduced from the isolated cDNAs revealed several interesting features, including hydrophobic signal and transmembrane domains that flank an extracellular region containing six potential attachment sites for glycosaminoglycan side chains. The structure also contains a short hydrophilic cytoplasmic tail sequence homologous to previously reported actin binding domains. Binding of basic FGF to cells expressing the binding protein could be inhibited by heparin and heparan sulfate but not by chondroitin sulfate, dermatan sulfate, or keratan sulfate. In addition to binding basic FGF, this protein or related surface proteins may function as an initial cellular attachment site for other growth factors and for viruses, such as herpes simplex virus.
Kiefer
M C
MC
Chiron Corporation, Emeryville, CA 94608.
Stephans
J C
JC
Crawford
K
K
Okino
K
K
Barr
P J
PJ
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002460:Cell Line; D011508:Chondroitin Sulfate Proteoglycans / Q000235:genetics* / Q000378:metabolism; D003001:Cloning, Molecular; D005346:Fibroblast Growth Factors / Q000378:metabolism*; D015723:Gene Library; D005822:Genetic Vectors; D006025:Glycosaminoglycans / Q000235:genetics*; D019812:Heparan Sulfate Proteoglycans; D006497:Heparan Sulfate / Q000235:genetics* / Q000378:metabolism; D006801:Humans; D008969:Molecular Sequence Data; D015345:Oligonucleotide Probes; D011485:Protein Binding; D011509:Proteoglycans / Q000235:genetics*; D015183:Restriction Mapping; D014162:Transfection
D011508:Chondroitin Sulfate Proteoglycans; D005346:Fibroblast Growth Factors; D006025:Glycosaminoglycans; D019812:Heparan Sulfate Proteoglycans; D006497:Heparan Sulfate; D015345:Oligonucleotide Probes; D011509:Proteoglycans