Glycolytic enzyme the catalyzes the conversion of 2-phosphoglycerate to phosphoenolpyruvate (PubMed:29775581, PubMed:1369209). In addition to glycolysis, involved in various processes such as growth control, hypoxia tolerance and allergic responses (PubMed:2005901, PubMed:10802057, PubMed:12666133, PubMed:29775581). May also function in the intravascular and pericellular fibrinolytic system due to its ability to serve as a receptor and activator of plasminogen on the cell surface of several cell-types such as leukocytes and neurons (PubMed:12666133). Stimulates immunoglobulin production (PubMed:1369209). MBP1 binds to the myc promoter and acts as a transcriptional repressor. May be a tumor suppressor. (2R)-2-phosphoglycerate = H2O + phosphoenolpyruvate Binds two Mg(2+) per subunit. Required for catalysis and for stabilizing the dimer. Enolase activity is lost above pH 9.0. Immunoglobulin production stimulating activity is retained at pH 13.0. Carbohydrate degradation; glycolysis; pyruvate from D-glyceraldehyde 3-phosphate: step 4/5. Mammalian enolase is composed of 3 isozyme subunits, alpha, beta and gamma, which can form homodimers or heterodimers which are cell-type and development-specific (PubMed:18560153). ENO1 interacts with PLG in the neuronal plasma membrane and promotes its activation. The C-terminal lysine is required for this binding (PubMed:9308760). Isoform MBP-1 interacts with TRAPPC2B (PubMed:11134351). Interacts with ENO4 and PGAM2 (By similarity). Interacts with CMTM6 (PubMed:28813417). Can translocate to the plasma membrane in either the homodimeric (alpha/alpha) or heterodimeric (alpha/gamma) form. ENO1 is localized to the M line. The alpha/alpha homodimer is expressed in embryo and in most adult tissues. The alpha/beta heterodimer and the beta/beta homodimer are found in striated muscle, and the alpha/gamma heterodimer and the gamma/gamma homodimer in neurons. During ontogenesis, there is a transition from the alpha/alpha homodimer to the alpha/beta heterodimer in striated muscle cells, and to the alpha/gamma heterodimer in nerve cells. Induced in diffuse large cell lymphoma (DLCL) after treatment with the natural biological agent, Bryo1. Up-regulated in response to enterovirus 71 (EV71) infection (at protein level). ISGylated. Lysine 2-hydroxyisobutyrylation (Khib) by p300/EP300 activates the phosphopyruvate hydratase activity. Used as a diagnostic marker for many tumors and, in the heterodimeric form, alpha/gamma, as a marker for hypoxic brain injury after cardiac arrest. Also marker for endometriosis. Antibodies against alpha-enolase are present in sera from patients with cancer-associated retinopathy syndrome (CAR), a progressive blinding disease which occurs in the presence of systemic tumor growth, primarily small-cell carcinoma of the lung and other malignancies. Is identified as an autoantigen in Hashimoto encephalopathy (HE) a rare autoimmune disease associated with Hashimoto thyroiditis (HT). HT is a disorder in which destructive processes overcome the potential capacity of thyroid replacement leading to hypothyroidism. It is uncertain whether the alternative initiation site is at Met-94 or at Met-97. Belongs to the enolase family. Sequencing errors.