Distribution of beta-enolase in normal and tumor rat cells.

Enolase - a glycolytic enzyme is also expressed on the surface of eukaryotic cells such as macrophages, neutrophils, endothelial, neuronal, tumor cells. Surface enolase as plasminogen receptor plays an important role in myogenesis, tumorgenesis and angiogenesis. Determination of enolase localization in the cell lines may give rise to the elucidation of its receptor function in tumor cells. The cellular localization of the muscle-specific isoform of the enolase in normal rat cardiomyocytes (H9c2, an embryonic rat heart-derived cell line) and a rat sarcoma (R1) cell line is reported here. Immunocytochemical assays showed that this enolase isoform is freely diffused in the sarcoplasm of rat cells. The evident location of enolase molecules on the perinuclear surface is observed in immunofluorescence assays. Enolase localization on the surface of some intact normal rat cardiomyocytes was also observed. This surface protein maintains enolase catalytic activity