Phosphorylation of human plasminogen activators and plasminogen.
Plasminogen (PG), urokinase-type plasminogen activator (u-PA) and tissue-type PA (t-PA) are the main molecules involved in fibrinolysis and in many other physiological and pathological processes. In the present study we report that human t-PA, purified from human melanoma cells, and PG, purified from human plasma, both contain P-Tyr residues, as revealed by immunoblotting analyses with monoclonal anti-P-Tyr antibodies. In addition HPLC amino acid analysis of acid-hydrolyzed t-PA, PG and u-PA, shows that: (i) P-Ser and P-Tyr residues are present in t-PA; (ii) P-Thr and P-Tyr are present in PG; (iii) P-Ser, P-Thr and P-Tyr are present in u-PA. The utilization of monoclonal anti-P-Ser and anti-P-Thr antibodies in immunoblotting experiments has confirmed these data which indicate that phosphorylation is a common feature of PAs and of PG.
Barlati
S
S
Department of Biomedical Sciences and Biotechnologies, University of Brescia, Italy.
De Petro
G
G
Bona
C
C
Paracini
F
F
Tonelli
M
M
D000911:Antibodies, Monoclonal; D002851:Chromatography, High Pressure Liquid; D006801:Humans; D015151:Immunoblotting; D008545:Melanoma; D010766:Phosphorylation; D010768:Phosphoserine / Q000032:analysis / Q000378:metabolism; D019000:Phosphotyrosine; D010958:Plasminogen / Q000378:metabolism*; D010960:Plasminogen Activators / Q000378:metabolism*; D010959:Tissue Plasminogen Activator / Q000378:metabolism; D014407:Tumor Cells, Cultured; D014443:Tyrosine / Q000031:analogs & derivatives* / Q000032:analysis / Q000378:metabolism; D014568:Urokinase-Type Plasminogen Activator / Q000378:metabolism
D000911:Antibodies, Monoclonal; D010768:Phosphoserine; D019000:Phosphotyrosine; D014443:Tyrosine; D010958:Plasminogen; D010960:Plasminogen Activators; D010959:Tissue Plasminogen Activator; D014568:Urokinase-Type Plasminogen Activator