Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: EC:4.6.1.1 (adenylate cyclase)
19,190 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The VIP receptor cloned from rat lung (VIP1 receptor from the group of the PACAP-VIP type II receptors) was inserted into a mammalian expression vector and stably transfected into Chinese hamster ovary cells (CHO). Two clones were selected, expressing respectively a high (850 +/- 50 fmol/mg protein, for clone 3) and a low (100 +/- 30 fmol/mg protein for clone 16) number of receptors. Both clones had the same apparent Kd value of binding for VIP and related peptides. The receptor expressed had the same binding properties as the natural VIP receptor, judged from the relative potency of VIP and PACAP analogues and fragments. The EC50 value of adenylate cyclase activation were 3 to 10 fold lower in clone 3 than in 16. The values observed in clone 16 were closer to the binding Kd values. The differences between the two clones were explained by the existence of spare receptors in clone 3, since: (a) the relative efficacy of some fragments were lower in clone 16 than in clone 3; (b) pretreatment of the cells with VIP reduced the number of receptors in both clones and increased the EC50 value for VIP in clone 3 but decreased peptide efficacy in clone 16 without significant change of the EC50 value.
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PMID:Properties of the VIP-PACAP type II receptor stably expressed in CHO cells. 771 73

In the present study, the effects of vasoactive intestinal peptide (VIP) and the pituitary adenylate cyclase-activating polypeptides, PACAP27 and PACAP38, in a concentration range from 10(-13) to 10(-6) mol/L were studied in vitro on the spontaneous and dexamethasone (DEX)-induced apoptosis in rat thymocytes. The results show that VIP and both PACAPs inhibit significantly and in a similar way the DNA fragmentation characteristic of glucocorticoid-induced apoptosis and increase the cell survival of thymocytes, with a maximal effect observed at 10(-8) to 10(-9) mol/L. This study showed the ability of the VIP-receptor (VIP-R) antagonist [N-Ac-Tyr1,D-Phe2]-GRF(1-29) amide to partially reverse the inhibitory effect of VIP and both PACAPs on DEX-induced apoptosis, providing evidence for a specific VIP1-R-mediated response and supporting the involvement of a single receptor for the three neuropeptides. Phenotypic analysis showed that VIP, PACAP27, and PACAP38 protect predominantly CD4+CD8+ thymocytes from glucocorticoid-induced apoptosis. These findings suggest that these neuropeptides could be involved in intrathymic T-cell maturation.
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PMID:Vasoactive intestinal peptide and pituitary adenylate cyclase-activating polypeptides (PACAP27) and PACAP38) protect CD4+CD8+ thymocytes from glucocorticoid-induced apoptosis. 865 28

The capability of rat pituitary cells to express receptors for pituitary adenylate cyclase activating polypeptide (PACAP) and VIP was evaluated by binding studies and measurement of adenylate cyclase activity on whole gland preparations and by reverse transcriptase-polymerase chain reaction (TR-PCR) using specific primers on preparations from isolated cell populations enriched in PRL- and GH-producing cells. Data obtained on whole gland preparations indicated that selective PACAP receptors (PACAP Type I) predominated. The mRNA coding for PACAP Type I and for the non-selective PACAP receptors Type II VIP2 (but not VIP1) were identified. The mRNA coding for four different spliced variants of the PACAP Type I receptor were detected. In PRL producing cells, three variants and the VIP2 mRNA were detected, whereas in GH-producing cells the mRNA coding for the variant having a 28-amino acid insert (termed HOP) in the third intracellular loop was the only present.
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PMID:Differential alternative splicing of PACAP receptor in pituitary cell subpopulations. 867 20

The ability of secretin, PACAP-(1-27)-peptide, and ten hybrid peptides to recognize and activate the rat secretin and vasoactive intestinal polypeptide (PACAP type II VIP1) receptors was tested on recombinant Chinese hamster ovary (CHO) cell lines. PACAP had a 2500-fold lower affinity than secretin for the secretin receptor, and secretin had a 300-fold lower affinity than PACAP for the VIP1 receptor. Amino acids 8, 13, and 15 of the PACAP molecule contributed significantly to the low affinity of PACAP for the secretin receptor. The amino acids at positions 5, 9, 10, 15, 16, and unidentified amino acid(s) between positions 17-20 made limited contributions to the low affinity of secretin for the VIP1 receptor. To identify the receptor region that interacts with these amino acids, we constructed chimeric receptors, which consist either of the N-terminal extracellular part of the secretin receptor and the core of the VIP1 receptor (N-Sn/VIP1r) or the N-terminal extracellular part of the VIP1 receptor and the core of the secretin receptor (N-VIP1/Snr), and tested the ability of the hybrid ligands to activate the adenylate cyclase of CHO cells expressing these chimeric receptors. The N-Sn/VIP1 receptors had a higher affinity for secretin than for PACAP. The hybrid peptide 6 that consists of the PACAP-(1-8)-Sn-(9-15)-PACAP-(16-27)-peptide sequence had a 30-fold to 200-fold higher potency than either parent peptide for the chimeric receptor, which suggests that while the N- and/or C-terminal part of the peptide interact with the transmembrane domain of the receptor, the discriminator region 9-15 recognizes the extracellular N-terminal domain of the receptor. This was confirmed by the observation that, out of all the peptides tested, hybrid 6 had the weakest potency for activation of the N-VIP1/Sn chimeric receptors.
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PMID:Interaction of amino acid residues at positions 8-15 of secretin with the N-terminal domain of the secretin receptor. 870 39

The expression of the pituitary adenylate cyclase-activating polypeptide/vasoactive intestinal polypeptide (PACAP/VIP) receptor subtypes was evaluated in the normal rat pituitary gland and in different rat spontaneous transplantable SMtTW tumours (SMtTW2 which expresses prolactin (PRL), SMtTW10 which expresses GH and SMtTW3 which expresses both PRL and GH) by measurement of PACAP/VIP-stimulated adenylate cyclase activity and detection of the presence of mRNA coding for the different receptor forms. In normal glands, the order of potency of the peptides suggested that adenylate cyclase activity was mediated through interaction with PACAP selective receptors (PACAP I receptors); mRNAs coding for the PACAP I receptor, but also for the PACAP II VIP2 receptor, were detected. In SMtTW2 tumours, the functional response was close to that observed in the presence of PACAP II VIP2 receptors; mRNAs coding for PACAP I and PACAP II VIP1 and PACAP II VIP2 receptors were detected. In the SMtTW10 tumours, the functional response was complex but compatible with the involvement of PACAP I and PACAP II receptors; mRNAs coding for the PACAP I and PACAP II VIP1 receptors were detected. In the SMtTW3 tumour, the profile was similar to that of the normal pituitary gland and the mRNA coding for the PACAP I receptor only was detected. Thus, while the control of normal pituitary gland adenylate cyclase activity by PACAP and VIP was mediated by PACAP-selective receptors, in spontaneous transplantable tumours a variable profile was observed and PACAP, as well as VIP1 and VIP2 receptors, may contribute to the responses.
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PMID:Pituitary adenylate cyclase-activating polypeptide/vasoactive intestinal polypeptide receptor subtypes are differently expressed in rat transplanted pituitary tumours (SMtTW) and in the normal gland. 878 82

We stably transfected Chinese hamster ovary (CHO) cells with the recombinant human vasoactive intestinal peptide (VIP)1 receptor. A clone referred to as Clone 15 was isolated and studied for receptor properties. The following data were obtained: (1) one class of binding site was identified by Scatchard analysis of [125I]VIP binding to cell membranes with a Kd of 0.41 nM and a Bmax of 1.62 pmol/mg protein; (2) the constant Ki for the inhibition of [125I]VIP binding by VIP and related peptides was: VIP (0.9 nM) = pituitary adenylate cyclase-activating peptide (PACAP)-27 (1.3 nM) < PACAP-38 (6.8 nM) < helodermin (46.0 nM) < human growth hormone-releasing factor (GRF) (0.6 microM) < peptide histidine methionineamide (2.0 microM) < secretin (> 10 microM); (3) cross-linking experiments using [125I]VIP identified a single M(r) 67000 recombinant receptor; (4) VIP stimulated cAMP production in Clone 15 cells with an EC50 of 0.20 nM; (5) some previously described VIP receptor antagonists including [4-Cl-D-Phe6, Leu17]VIP, [Ac-Tyr1,D-Phe2]GRF-(1-29) amide and VIP-(10-28) inhibited [125I]VIP binding with a Ki of 0.7, 1.6 and 2.5 microM, respectively. They failed to stimulate cAMP production in Clone 15 cells and inhibited, at least partially, the VIP (0.3 nM)-evoked cAMP production; (6) exposure of Clone 15 cells to 10 nM VIP for 24 h resulted in a sharp decrease in Bmax in Clone 15 cells (0.43 vs. 1.62 pmol/mg protein in control cells) and in the potency and efficacy of VIP in stimulating cAMP. Moreover, immunofluorescence studies using confocal microscopy indicated that the receptor was internalized and sequestered in vesicular structures within the cells. It is concluded that Clone 15 cells provide a valuable tool to further characterize various functional and pharmacological aspects of the human VIP1 receptor.
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PMID:Stable expression of the recombinant human VIP1 receptor in clonal Chinese hamster ovary cells: pharmacological, functional and molecular properties. 879 Oct 9

Pituitary adenylate cyclase-activating polypeptide (PACAP) analogues were tested for their ability to occupy the recombinant selective PACAP receptors (PACAP type I receptors) and the non-selective PACAP-vasoactive intestinal polypeptide (VIP) receptors (PACAP type II, VIP1 and PACAP type II, VIP2 receptors), stably transfected and expressed in Chinese hamster ovary cells. Their capacity to stimulate the adenylate cyclase activity was also measured. The synthetic analogues tested were peptides shortened at the carboxyl terminus by the removal of 1-4 amino acids (PACAP-26 to PACAP-23). All the peptides discriminated the 3 receptor subtypes and had the highest affinity for the VIP1 receptors, and the lowest affinity for the VIP2 receptors; PACAP-25 having the highest ability to discriminate the VIP1 and VIP2 receptors. All the peptides tested were full agonists on the PACAP I and VIP1 receptors; PACAP-25 and -26 were partial agonists on VIP2 receptors and may be appropriate tools to establish the receptor subtype involved in a given cellular response.
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PMID:C-terminally shortened pituitary adenylate cyclase-activating peptides (PACAP) discriminate PACAP I, PACAP II-VIP1 and PACAP II-VIP2 recombinant receptors. 879 75

Pituitary adenylate cyclase-activating peptide (PACAP) is present and synthesized in the testis in large amounts. Messenger RNA encoding the peptide is expressed in a stage specific manner in the developing germ cells. PACAP regulates a variety of physiological actions, among them, paracrine modulation of spermatogenesis. The PACAP peptides are potential ligands of at least three receptor types, the type I PACAP receptor, VIP1 and VIP2 receptors. Although PACAP27 binding sites have found in the testis, the receptor at which it acts has not been identified. We used in situ hybridization with riboprobes to identify the PACAP binding receptor present in the testis. Neither type I PACAP receptor, nor VIP1 receptor mRNA was present within the germ cells. Using the VIP2 receptor probe there was strong labelling within some cross sections of the seminiferous tubuli, while others were not labelled. The in situ results were also confirmed using reverse-transcription PCR (RT-PCR). Our data suggest that PACAP mediates its possible paracrine effect in the testis through the VIP2 receptor.
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PMID:PACAP acts through VIP type 2 receptors in the rat testis. 883 57

C-terminally truncated secretin and VIP molecules were synthesized, and their ability to occupy the recombinant secretin and VIP1 receptors stably expressed in Chinese hamster ovary (CHO) cells and to stimulate adenylate cyclase activity was studied. On secretin receptors, secretin (1-26) and secretin (1-24) were 10- and 50-fold less potent but as efficient as secretin (1-27); VIP (1-27) was as potent and efficient as VIP (1-28), and VIP (1-26) and VIP (1-25) were both 100-fold less potent. On VIP1 receptor, VIP (1-28) and VIP (1-27) were equipotent and VIP (1-26) and VIP (1-25) were 10- and 300-fold less potent, respectively; secretin (1-27) and secretin (1-26) were of equally low affinity and 10-fold more potent than secretin (1-24). Thus, the secretin and the VIP1 receptors had different selectivity profiles for the recognition of C-terminally truncated secretin and VIP derivatives. The chimeric receptors consisting in the N-terminal part of the secretin receptor on the core of the VIP1 receptor (N-Sn/VIP1.r) and in the N-terminal part of the VIP1 receptor on the core of the secretin receptor (N-VIP1/Sn.r) exhibited the selectivity pattern of the secretin and VIP1 receptors, respectively. The results suggest that the C-terminal end of secretin and VIP interacts with the N-terminal domain of the secretin and VIP receptors.
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PMID:The C-terminus ends of secretin and VIP interact with the N-terminal domains of their receptors. 884 73

We analyzed the functional and binding properties of the "normal" pituitary adenylate cyclase-activating polypeptide (N-PACAP) type I, PACAP type II/vasoactive intestinal peptide (VIP)1, and chimeric N-PACAP/VIP1 receptors expressed in Chinese hamster ovary cells. The binding properties of the three receptors were investigated using three radioiodinated tracers: 125I-VIP, 125I-PACAP-27, and 125I-PACAP-29 (125I-PACAP-27-Gly28,Lys29-amide). The three tracers labeled very different receptor densities; 125I-PACAP-29 labeled more receptors than either 125I-VIP or 125I-PACAP-27 in the three cell lines. Analysis of the competition curves suggested that the three tracers labeled in a different manner three PACAP I receptor states, two PACAP II/VIP1 receptor states, and three chimeric N-PACAP/VIP1 receptor states in transfected Chinese hamster ovary cells. The previously described PACAP1A and PACAP1B receptors, which differ by their affinities for PACAP-27 and PACAP-38, actually correspond to different PACAP I receptor states. The three receptors were able to increase adenylate cyclase activity when activated by PACAP-38, PACAP-27, or VIP. In contrast with the two parent receptors, the chimeric N-PACAP/VIP1 receptor was activated by PACAP-38 at lower concentrations than PACAP-27, suggesting that the amino-terminal and core receptor domains influence each other and that the conformation of one or both domains was altered in the chimeric compared with wild-type receptors. Comparison of the binding and functional properties of three clones expressing different chimeric N-PACAP/VIP1 receptors densities indicated that 125I-PACAP-29 was necessary to correctly estimate the receptor number and that 125I-PACAP-27 or 125I-VIP labeled only a fraction of the functional receptors. We suspect (but could not demonstrate) that this might also be true for PACAP I and PACAP II/VIP1 receptors.
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PMID:Properties of the pituitary adenylate cyclase-activating polypeptide I and II receptors, vasoactive intestinal peptide1, and chimeric amino-terminal pituitary adenylate cyclase-activating polypeptide/vasoactive intestinal peptide1 receptors: evidence for multiple receptor states. 896 82


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