Thy-1 is a neuronal and glial surface antigen which interacts with matrix proteins and plasminogen activator.
Thy-1 antigen is expressed at high levels in the thymus and in adult brain of rodents however its function remains undetermined. We report that immobilised Thy-1 binds laminin, fibronectin and the less active precursor form of the tissue type plasminogen activator (t-PA) yet it does not bind urokinase. The incorporation of serine protease inhibitors within the experimental procedures suggested that Thy-1 bound to the lysine-containing, protein-binding domain of t-PA thus leaving the active site available to interact with other proteins. By using an immunocytochemical approach designed to maximally preserve Thy-1 antigenicity, we were able to demonstrate that in the adult rat peripheral nervous system (PNS) Thy-1 was seen to co-localise with laminin on the Schwann cell membranes and accumulated at the nodes of Ranvier within sciatic nerve. The only neuronal structures to express Thy-1 within the PNS were the unmyelinated nerve fibres. In the adult rat central nervous system (CNS), the most distinct and novel association of Thy-1 was its presence along the myelin forming glial cells and their fibres.
Liësi
P
P
Recombinant DNA Laboratory, University of Helsinki, Finland.
Salonen
E M
EM
Dahl
D
D
Vaheri
A
A
Richards
S J
SJ
D000818:Animals; D000954:Antigens, Surface / Q000378:metabolism*; D002478:Cells, Cultured; D005353:Fibronectins / Q000378:metabolism*; D007797:Laminin / Q000378:metabolism*; D009457:Neuroglia / Q000378:metabolism*; D009474:Neurons / Q000378:metabolism*; D051381:Rats; D018800:Thy-1 Antigens; D010959:Tissue Plasminogen Activator / Q000378:metabolism*
D000954:Antigens, Surface; D005353:Fibronectins; D007797:Laminin; D018800:Thy-1 Antigens; D010959:Tissue Plasminogen Activator