Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P56851 (epididymal)
 11,273 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Albumin enhances prostaglandin E2 (PGE2) binding to isolated epididymal adipocyte membrane and also binds PGE2 with low affinity. On the other hand, S-100, ovalbumin and albumin-stearate failed to bind PGE2, as shown by ultrafiltration, and also failed to enhance PGE2 binding to the isolated adipocyte membranes. These results suggested that albumin enhances PGE2 binding possibly by serving as a carrier for the prostaglandin molecules. 3 mM warfarin or 1 mM phenylbutazone inhibited PGE2 binding to albumin by 70% and 95%, respectively, but both drugs failed to affect the enhancement of PGE2 binding to the isolated adipocyte membrane in the presence of albumin. These results exclude the possibility that PGE2 bound to albumin is more accessible to the prostaglandin receptor than free PGE2 in solution. Finally it is shown that fatty acid binding protein (FABP), a cytosolic protein which binds specifically PGE1 but not PGE2, enhances PGE1 and PGE2 binding to isolated adipocyte membranes similarly to albumin. The physiological implications of these findings are discussed.
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PMID:Fatty acid binding protein (FABP) modulates prostaglandin E binding to rat epididymal adipocyte membrane similarly to albumin. 210 54

We recently identified four isoforms of bovine prostaglandin E receptor EP3 subtype, which are coupled to different signaling pathways; EP3A is coupled to inhibition of adenylate cyclase, while EP3B and EP3C are coupled to its stimulation and EP3D is coupled to phosphatidylinositol turnover, in addition to the adenylate cyclase system (Namba, T., Sugimoto, Y., Negishi, M., Irie, A., Ushikubi, F., Kakizuka, Ito, S., A., Ichikawa, A., and Narumiya, S. (1993) Nature 365, 166-170). We examined here the identity of coupled G proteins and their regulation by one of the isoforms, EP3C, in the membranes of EP3C cDNA-transfected Chinese hamster ovary cells. M&B 28767, an EP3 agonist, stimulated the GTPase activity in the pertussis toxin (PT)-treated cell membrane, but inhibited it in the cholera toxin (CT)-treated cell membrane, while the agonist neither stimulated nor inhibited it in the both PT- and CT-treated cell membrane. In the PT- and CT-treated cell membrane reconstituted with various G proteins, M&B 28767 inhibited the GTPase activity of G(o), but stimulated that of Gs. On the other hand, M&B 28767 did not affect the GTPase activity of Gi1, Gi2, or Gi3. M&B 28767 increased the apparent affinity of G(o) for GDP without any change in that for GTP, as assessed by displacement of [35S]GTP gamma S (guanosine 5'-O-(3-thiotriphosphate)) binding to G(o). In contrast, M&B 28767 increased the apparent affinity of Gs for GTP but decreased that for GDP. These results demonstrated that the EP3 receptor isoform is coupled to two different G proteins, and oppositely regulates their activities, inhibition of G(o), and stimulation of Gs.
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PMID:Opposite coupling of prostaglandin E receptor EP3C with Gs and G(o). Stimulation of Gs and inhibition of G(o). 825 19

We previously reported that the activation of prostaglandin E receptor EP3 subtype caused neurite retraction via small GTPase Rho in the EP3B receptor-expressing PC12 cells (Katoh, H., Negishi, M., and Ichikawa, A. (1996) J. Biol. Chem. 271, 29780-29784). However, a potential downstream effector of Rho that induces neurite retraction was not identified. Here we examined the morphological effect of p160 RhoA-binding kinase ROKalpha, a target for RhoA recently identified, on the nerve growth factor-differentiated PC12 cells. Microinjection of the catalytic domain of ROKalpha rapidly induced neurite retraction similar to that induced by microinjection of a constitutively active Rho, RhoV14, whereas microinjection of the kinase-deficient catalytic domain of ROKalpha did not induce neurite retraction. This morphological change was observed even though C3 exoenzyme, which was known to inactivate Rho, had been preinjected. On the other hand, microinjection of the Rho-binding domain or the pleckstrin homology domain of ROKalpha inhibited the EP3 receptor-induced neurite retraction. These results demonstrate that ROKalpha induces neurite retraction acting downstream of Rho in neuronal cells.
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PMID:p160 RhoA-binding kinase ROKalpha induces neurite retraction. 944 46