enolase-1, alpha enolase or phosphopyruvate hydratase

Formerly phosphopyruvate hydratase Function: - multifunctional enzyme - role in glycolysis - role in growth control, hypoxia tolerance & allergy - role in intravascular & pericellular fibrinolytic system due to its ability to serve as a receptor & activator of plasminogen on the cell surface of several cell-types including leukocytes & neurons (putative) - binds to the c-myc promoter & acts as a transcriptional repressor - may be a tumor suppressor - ENO1 interacts with PLG in the neuronal plasma membrane & promotes its activation; C-terminal lysine is required for binding - carbohydrate degradation, glycolysis, pyruvate from D-glyceraldehyde 3-phosphate: step 4/5 2-phospho-D-glycerate phosphoenolpyruvate + H₂O Cofactor: - Mg⁺², required for catalysis & for stabilizing the dimer Structure: - belongs to the enolase family - mammalian enolase is composed of 3 isozyme subunits, alpha, beta & gamma, which can form homodimers or heterodimers which are cell-type & development-specific Compartment: - cytoplasm, cell membrane, myofibril, sarcomere, M-band - can translocate to the plasma membrane in either the homodimeric (alpha/alpha) or heterodimeric (alpha/gamma) form - localized to the M-band - isoform MBP-1: nucleus Alternative initiation: - named isoforms=2 Expression: - alpha/alpha homodimer is expressed in embryo & in most adult tissues - alpha/beta heterodimer & beta/beta homodimer are found in striated muscle - the alpha/gamma heterodimer & the gamma/gamma homodimer are found in neurons - during ontogenesis, there is a transition from the alpha/alpha homodimer to the alpha/beta heterodimer in striated muscle cells, & to the alpha/gamma heterodimer in nerve cells Pathology: - induced in diffuse large cell lymphoma (DLCL) after treatment with the natural biological agent, Bryo1 - ENO1 is identified as an autoantigen in Hashimoto encephalopathy - antibodies against alpha-enolase are present in sera from patients with cancer-associated retinopathy syndrome (CAR) - used as a diagnostic marker for many tumors - in the heterodimeric form, alpha/gamma, as a marker for hypoxic brain injury after cardiac arrest - marker for endometriosis Genetics: - may be encoded by same gene that encodes tau crystallin

Specific

enolase-1 (p47) enolase-1, lung-specific (p49)

General

enolase (2-phospho-D-glycerate hydrolase) phosphoprotein

Properties

CONFIGURATION: dimer SIZE: entity length = 434 aa MW = 47 kD COMPARTMENT: cytoplasm cell nucleus MOTIF: CAR epitope {31-38} Tyr phosphorylation site {Y44} CAR epitope {56-63} MOTIF: Tyr phosphorylation site {Y57} Ser phosphorylation site {S63} Thr phosphorylation site {T72} c-myc promoter repression {97-237} MOTIF: binding site SITE: 158-158 FOR-BINDING-OF: Substrate binding site SITE: 167-167 FOR-BINDING-OF: Substrate glutamate residue {E210} Mg+2-binding site SITE: 245-245 Ser phosphorylation site {S263} Tyr phosphorylation site {Y287} Mg+2-binding site SITE: 293-293 MOTIF: binding site SITE: 293-293 FOR-BINDING-OF: Substrate Mg+2-binding site SITE: 318-318 MOTIF: binding site SITE: 318-318 FOR-BINDING-OF: Substrate lysine residue {K343} Substrate binding {370-373} binding site SITE: 394-394 FOR-BINDING-OF: Substrate PLG interaction {405-434}

Database Correlations

OMIM 172430 UniProt P06733 PFAM correlations Entrez Gene 2023 ENZYME 4.2.1.11