Chicken gizzard 5'-nucleotidase is a receptor for the extracellular matrix component fibronectin.
The smooth muscle cells of chicken gizzard harbor the ectoenzyme 5'-nucleotidase. The purified enzyme was reconstituted into 3H-labeled proteoliposomes which were used as a model to study the association of a membrane protein with fibronectin. We demonstrated that the binding process between proteoliposomes and fibronectin has the qualities of a receptor-ligand interaction, i.e., is saturable and specific. In contrast to the association of fibronectin with integrins, the interaction with 5'-nucleotidase does not require divalent metal ions. Synthetic peptides containing the RGD-sequence or a monoclonal antibody interfering with binding of other receptors to the cell-binding domain of fibronectin did not abolish the interaction with 5'-nucleotidase. This indicates that the RGDS-sequence does not represent the major contact site for the AMPase and that the 5'-nucleotidase belongs to a separate class of fibronectin receptors with distinct properties as compared to the integrins.
Stochaj
U
U
Institut für Anatomie und Zellbiologie der Universität, Marburg/Bundesrepublik Deutschland.
Richter
H
H
Mannherz
H G
HG
D015720:5'-Nucleotidase / Q000378:metabolism / Q000502:physiology*; D000595:Amino Acid Sequence; D000818:Animals; D002645:Chickens; D005353:Fibronectins / Q000378:metabolism*; D005895:Gizzard, Avian / Q000201:enzymology*; D006358:Hot Temperature; D007700:Kinetics; D008081:Liposomes; D008670:Metals; D008969:Molecular Sequence Data; D017469:Receptors, Fibronectin; D011971:Receptors, Immunologic
D005353:Fibronectins; D008081:Liposomes; D008670:Metals; D017469:Receptors, Fibronectin; D011971:Receptors, Immunologic; D015720:5'-Nucleotidase