Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P01189 (beta-endorphin)
 21,003 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Membrane glycoproteins of neural cells play crucial roles in axon guidance, synaptogenesis, and neuronal transmission. We have here characterized membrane glycoproteins containing terminal alpha-mannose residues in rat brain membranes. Affinity purification using Galanthus nivalis agglutinin, that is highly specific for terminal alpha-mannose residues, revealed a 50-kDa protein as well as 80-kDa SHPS-1 and 45-kDa beta2 subunit of Na,K-ATPase in rat brain membranes. Combination of N-terminal peptide sequencing and mass spectrometry indicated that the 50-kDa protein was rat nucleotide pyrophosphatase-5 (NPP-5). In contrast to other NPPs, NPP-5 was a type-I transmembrane protein. Northern blot analysis showed that NPP-5 was highly expressed in brain, but also expressed in other peripheral tissues. However, we could not detect either the NPP activity or the lysophospholipase D activity in the immunoprecipitates with antibodies to NPP-5 from rat brain membranes. These data, therefore, suggest that NPP-5 is a neural oligomannosidic glycoprotein that may participate in neural cell communications.
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PMID:Characterization of nucleotide pyrophosphatase-5 as an oligomannosidic glycoprotein in rat brain. 1292 78

Autotaxin (ATX) or nucleotide pyrophosphatase/phosphodiesterase 2 (NPP2) is an NPP family member that promotes tumor cell motility, experimental metastasis, and angiogenesis. ATX primarily functions as a lysophospholipase D, generating the lipid mediator lysophosphatidic acid (LPA) from lysophosphatidylcholine. ATX uses a single catalytic site for the hydrolysis of both lipid and non-lipid phosphodiesters, but its regulation is not well understood. Using a new fluorescence resonance energy transfer-based phosphodiesterase sensor that reports ATX activity with high sensitivity, we show here that ATX is potently and specifically inhibited by LPA and sphingosine 1-phosphate (S1P) in a mixed-type manner (Ki approximately 10(-7) M). The homologous ecto-phosphodiesterase NPP1, which lacks lysophospholipase D activity, is insensitive to LPA and S1P. Our results suggest that, by repressing ATX activity, LPA can regulate its own biosynthesis in the extracellular environment, and they reveal a novel role for S1P as an inhibitor of ATX, in addition to its well established role as a receptor ligand.
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PMID:Inhibition of autotaxin by lysophosphatidic acid and sphingosine 1-phosphate. 1576 51

Autotaxin (ATX/NPP2) shows a nucleotide pyrophosphatase/phosphodiesterase and lysophospholipase D (lysoPLD) activity and is a member of a family of structurally-related mammalian ecto-nucleotide pyrophosphate/phosphodiesterases (E-NPP1-3). ATX is unique among E-NPP as it is secreted and not membrane-bound as are NPP1 and -3. The ATX gene activity is significantly higher in undifferentiated anaplastic (UTC) as compared to follicular (FTC) and papillary thyroid carcinomas (PTC) or goiter tissues. ATX also enhances the motility of thyroid tumor cells. We bio-engineered stable transfectants of the human thyroid carcinoma cell line FTC-238 expressing either bioactively-secreted (sATX) or membrane-anchored ATX (mATX) to identify the biological functions of ATX which critically depend on the E-NPP member being secreted and provide insight into the effects of high local ATX concentrations and cellular responses. An increased cell motility was exclusively observed with FTC-238 sATX transfectants, whereas membrane-anchored ATX appeared to impair motility. We identified IL-1beta as an upstream suppressor of ATX expression in FTC-238, ATX-mediated motility in FTC-238 and stable transfectants, with IL-1beta having the strongest motility-suppressive effect on FTC-238 sATX clones. sATX and mATX strongly increased the anchorage-independent colony formation of FTC-238 but the size and number of colonies formed in the soft agar were significantly smaller in FTC-238 mATX versus the FTC-238 sATX clones. The cancer-testis antigen BAGE was identified as a novel target gene of ATX in FTC-238. Transcript levels for BAGE were 6-fold higher in FTC-238 mATX versus sATX clones. Increased BAGE transcript levels were also detected in tissues of patients with UTC versus FTC, PTC or goiter tissues. In summary, enhanced tumor cell motility and tumorigenic capacity critically depended on sATX in thyroid carcinoma cells. Irrespective of its compartmentalization, the cancer-testis antigen BAGE was identified as a novel target gene of ATX in FTC-238 and a potential new tissue marker in UTC tissues, which we had previously shown to express high levels of ATX.
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PMID:The cellular localization of autotaxin impacts on its biological functions in human thyroid carcinoma cells. 1849 54