INCREASED EXPRESSION OF ALPHA-ENOLASE IN C-JUN TRANSFORMED RAT FIBROBLASTS WITHOUT INCREASED ACTIVATION OF PLASMINOGEN

Two-dimensional gel electrophoresis was used to identify polypeptides differentially expressed between normal and c-jun transformed rat fibr oblasts, The level of a 49 kDa polypeptide was 3-fold elevated in c-ju n transformed cells, Sequence analysis by ion trap mass spectrometry i dentified the polypeptide as rat alpha-enolase, Enolase functions as a cell surface receptor for plasminogen, suggesting that upregulation m ay increase plasminogen activation and cell surface proteolysis import ant for tumor growth, However, no difference was observed between norm al and transformed cells in formation of plasmin, suggesting that upre gulation of alpha-enolase may contribute to an increased metabolic cap acity, but not to increased plasminogen activation, (C) 1997 Federatio n of European Biochemical Societies.