Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P67775 (alpha isoform)
 797 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In this report, we define a muscle-specific marker, beta-enolase, that distinguishes proliferating myoblasts from different stages of development. Enolase exists as multiple isoforms and in the course of cardiac and skeletal muscle development the beta isoform progressively replaces the alpha isoform. In skeletal muscle, this change in gene expression, unlike most developmental changes in myogenic gene expression, is evident in undifferentiated myoblasts. Whereas myoblasts from fetal tissues express alpha-enolase mRNA, beta-enolase is the predominant mRNA expressed by myoblasts from postnatal tissues. Our results are consistent with the idea that distinct precursor myoblasts contribute to the diversity of fiber types characteristic of muscle tissue at different stages of development.
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PMID:Beta-enolase is a marker of human myoblast heterogeneity prior to differentiation. 133 35

By virtue of their capacity to bind plasminogen activators and plasminogen, to accelerate plasminogen activation and to protect bound plasmin from inactivation by alpha 2 antiplasmin, cells can harness the broad proteolytic activity of plasmin to their surface. Most cells bind plasminogen with a very high capacity, a relatively low affinity (Kd approximately 1 microM) and recognize the lysine binding sites of the molecule. Gangliosides serve as non-protein plasminogen binding sites, and a subset of membrane proteins with carboxy-terminal lysine residues also serve as receptors. The alpha isoform of enolase possesses a carboxy-terminal lysine and is a prominent plasminogen binding protein of cells. Cells of the monocytoid lineage, including peripheral blood monocytes, can markedly upregulate their expression of plasminogen receptors. The capacity to modulate expression of receptors for fibrinolytic components establishes an additional mechanism by which the cell-surface regulates the function of the plasminogen system.
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PMID:Cellular regulation of fibrinolysis. 165 42

The alpha isoform of enolase is a candidate plasminogen receptor on U937 monocytoid cells [Miles, L. A., Dahlberg, C. L., Plescia, J., Felez, J., Kato, K. & Plow, E. F. (1991) Biochemistry 30, 1682-1691]. In the present study, an enolase-related molecule was detected on the surfaces of peripheral blood monocytes and neutrophils by fluorescence-activated cell sorting. A mRNA transcript encoding a unique membrane form of an enolase-related molecule was not detected by Northern-blotting and primer-extension analyses, consistent with the cell-surface protein being authentic alpha-enolase. Both the alpha and beta isoforms of purified enolase, bound plasminogen with an affinity similar to that of the cell surface. Moreover, immunopurified alpha-enolase enhanced plasminogen activation by tissue plasminogen activator and blocked the binding of plasminogen to alpha 2-antiplasmin, mimicking functions arising from the association of plasminogen with cells. The interaction of the enolase isoforms with plasminogen was dependent upon recognition of the C-terminal lysyl residue of the enolases by the lysine-binding sites of plasminogen, as the interaction was blocked by (a) peptides with C-terminal lysine residues and (b) an antibody to the C-terminal aspect of enolase. A monoclonal antibody was developed, characterized and utilized to quantify the enolase molecules present on the surface of U937 cells. A substantial number of molecules, 1.8 x 10(6)/cell, was present, accounting for approximately 10% of the plasminogen-binding capacity of these cells. These studies clearly establish the role of enolase as a cell-surface plasminogen-binding site with profibrinolytic functions.
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PMID:The role of an enolase-related molecule in plasminogen binding to cells. 785 15

Anti-neutrophil cytoplasmic antibodies (ANCA) in sera from patients with clinically proven vasculitis have been described as reacting with proteins present in the granules of human neutrophils. We have studied sera from 59 ANCA positive patients to further characterize the antibody response. In addition to the antigens previously identified in the vasculitic syndromes (myeloperoxidase and serine proteinase 3) the majority of these sera contained antibodies that reacted with a cytosolic extract of neutrophils on Western blots. Nearly 40% of these sera had antibodies directed against a cytosolic protein(s) of molecular mass 48 kD. This protein was purified from neutrophil cytosol by ammonium sulphate fractionation, anion exchange and reverse phase chromatography. Amino acid sequence analysis of a proteolytic fragment of this protein identified it as alpha enolase. The anti-enolase antibodies only recognized the alpha isoform and were present in sera giving either a pANCA or cANCA staining pattern by indirect immunofluorescence. Antibodies to alpha enolase were also found in sera from patients with systemic lupus erythematosus, particularly those with renal disease. We conclude that the antibody response in ANCA positive vasculitis is not restricted to neutrophil granule proteins.
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PMID:Alpha-enolase: a novel cytosolic autoantigen in ANCA positive vasculitis. 845 67

Enolase is a glycolytic enzyme whose amino acid sequence is highly conserved across a wide range of animal species. In mammals, enolase is known to be a dimeric protein composed of distinct but closely related subunits: alpha (non-neuronal), beta (muscle-specific), and gamma (neuron-specific). However, little information is available on the primary sequence of enolase in invertebrates. Here we report the isolation of two overlapping cDNA clones and the putative primary structure of the enzyme from the squid (Loligo pealii) nervous system. The composite sequence of those cDNA clones is 1575 bp and contains the entire coding region (1302 bp), as well as 66 and 207 bp of 5' and 3' untranslated sequence, respectively. Cross-species comparison of enolase primary structure reveals that squid enolase shares over 70% sequence identity to vertebrate forms of the enzyme. The greatest degree of sequence similarity was manifest to the alpha isoform of the human homologue. Results of Northern analysis revealed a single 1.6 kb mRNA species, the relative abundance of which differs approximately 10-fold between various tissues. Interestingly, evidence derived from in situ hybridization and polymerase chain reaction experiments indicate that the mRNA encoding enolase is present in the squid giant axon.
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PMID:Characterization of squid enolase mRNA: sequence analysis, tissue distribution, and axonal localization. 858 50

We report the presence and distribution of alpha (ubiquitous) and gamma (neuron-specific) subunits of the dimeric glycolytic enzyme enolase (2-phospho-D-glycerate hydrolase) in cultured neural cells. The gamma gamma enolase is found in vivo at high levels only in neurons and neuroendocrine cells. Neuronal cells in culture also contain relatively high levels of alpha gamma and gamma gamma enolase. Here we show, by enzymatic and immunological techniques, that the gamma subunit also is expressed in cultured rat astrocytes and meningeal fibroblasts and, as we previously reported, in oligodendrocytes. Both neuron-specific isoforms alpha gamma and gamma gamma are expressed in all these cells, but the alpha alpha isoform accounts for the major part of total enolase activity. The sum of alpha gamma and gamma gamma enolase activities increases with time in culture. i.e. maturation processes, reaching the highest level in oligodendrocytes (40% of total enolase activity) and 15 and 10% of total enzymatic activity in astrocytes and fibroblasts, respectively. The gamma enolase transcripts were found not only in cultured neuronal cells but also in cultured oligodendrocytes astrocytes, and meningeal fibroblasts. Our data indicate that neuron-specific enolase should be used with caution as a specific marker for neuronal cell differentiation.
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PMID:A comparative study of the distribution of alpha- and gamma-enolase subunits in cultured rat neural cells and fibroblasts. 917 37

We examined the expression and localisation of enolase (2-phospho-D-glycerate hydrolase) in differentiating rat spermatogenic cells. We found that enolase is most abundant in mature spermatozoa and in residual cytoplasmic bodies detached from elongating spermatids with little to no enolase detected in meiotic primary spermatocytes and round spermatids. We localised enolase mostly to the tail of mature spermatozoa by immunoblotting and by immunofluorescence. RT-PCR analysis of differentiating spermatogenic cells detected only the alpha isoform of enolase. As several glycolytic enzymes are known to associate with microtubules prepared from brain, we investigated the association of enolase with brain and testis microtubules. We found that only a small fraction of testis and brain-derived cytosolic enolase (4.9% and 11.2%, respectively) co-sediments with microtubules stabilised in the presence of taxol. In the presence of certain nucleotides in excess (3 mM ATP, CTP, GTP and ITP) the association of enolase with microtubules was disrupted, however, this was not the case for UTP. This observation is consistent with the finding that in the presence of 0.5 mM AMP-PNP, a nonhydrolysable analogue of ATP, there is an increased association of enolase with microtubules. We propose that the nucleotide-dependent association of enolase with microtubules regulates enzyme activity by linking energy production to utilisation.
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PMID:The glycolytic enzyme enolase is present in sperm tail and displays nucleotide-dependent association with microtubules. 1072 18

We have analyzed the proteomes of two human melanoma cell lines (A375 and 526), and of the human melanocytes, (FOM 78), by two-dimensional electrophoresis (2D-PAGE) and liquid chromatography - tandem mass spectrometry (LC-MS/MS). Our comparative proteomic analysis revealed that six proteins were over-expressed in both melanoma cell lines as compared to melanocytes: galectin-1, inosine-5'-monophosphate dehydrogenase 2, serine/threonine-protein phosphatase 2A 65 kDa regulatory subunit A alpha isoform, protein DJ-1, cyclophilin A and cofilin-1. We show, for the first time, that only specific isoforms of these molecules are over-expressed in melanoma. Different protein profiles were also found between each individual melanoma cell line and the melanocytes. s-Methyl-5-thioadenosine phosphorylase, ubiquitin and ribosomal protein S27 a precursor, the basic form of protein DJ-1, annexin a1, proliferation associated protein 2g4, isoform alfa-enolase of alfa-enolase, protein disulfide-isomerase precursor, and elongation factor 2 were more strongly expressed in A375 cells compared to melanocytes. In 526 cells, 60s acidic ribosomal protein p1 and calreticulin precursor were more highly expressed than in melanocytes. These molecular differences may help in better understanding melanoma development and its different responsiveness to therapies. The identified proteins could be exploited as biomarkers or therapeutic targets for melanoma.
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PMID:Characterization of human melanoma cell lines and melanocytes by proteome analysis. 2185 57