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
Query: EC:4.6.1.1 (
adenylate cyclase
)
19,190
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
Using PC12 cells as an in vitro model system, we have identified a series of transcripts induced through activation of the leptin receptor. On the basis of kinetic studies, two distinct gene sets could be discerned: signal transducer and activator of transciption-3 (STAT-3), suppressor of cytokine signalling-3 (SOCS-3),
MT-II
(metallothionein-II), the serine/threonine kinase fibroblast-growth-factor-inducible kinase (Fnk) and modulator recognition factor (MRF-1), which are immediate early response genes, and pancreatitis-associated protein I (PAP I), squalene epoxidase, uridine diphosphate glucuronosyltransferase and annexin VIII, which are late induced target genes. At late time points a strong co-stimulation with beta-nerve growth factor or with the
adenylate cyclase
activator forskolin was observed. To assess the validity of the PC12-cell model system, we examined the effect of leptin administration on the gene transcription of STAT-3,
MT-II
, Fnk and PAP I in vivo. Leptin treatment of leptin-deficient ob/ob mice increased the STAT-3, SOCS-3,
MT-II
and Fnk mRNA, and MT-I protein levels in liver, whereas, in jejunum, expression of PAP I mRNA was down-regulated. Furthermore, administration of leptin to starved wild-type mice enhanced the expression of
MT-II
and Fnk mRNA in liver, but decreased
MT-II
and PAP I mRNA expression in jejunum. These findings may help to explain the obese phenotype observed in some colonies of MT-I- and
MT-II
-null mice and/or the observation that leptin protects against tumour-necrosis-factor toxicity in vivo.
...
PMID:Identification and expression analysis of leptin-regulated immediate early response and late target genes. 1079 13
Differentiation of the physiological role of the melanocortin receptor 5 MC5R from that of other melanocortin receptors will require development of high affinity and selective antagonists. To date, a few synthetic antagonist ligands active at hMC5 receptor are available, but most do not have appreciable selectivity. With the aim to gain more potent and selective antagonists for the MC5R ligands, we have designed, synthesized, and pharmacologically characterized a series of alkylthioaryl-bridged macrocyclic peptide analogues derived from
MT-II
and SHU9119. These 20-membered macrocycles were synthesized by a tandem combination using solid phase peptide synthesis and microwave-assisted reactions. Biological assays for binding affinities and
adenylate cyclase
activities for the hMC1R, hMC3R, hMC4R, and hMC5R showed that three analogues, compounds, 9, 4, and 7, are selective antagonists at the hMC5 receptor. In particular, compound 9(PG-20N) is a selective and competitive hMC5R antagonist, with IC 50 of 130 +/- 11 nM, and a pA 2 value of 8.3, and represents an important tool for further biological investigations of the hMC5R. Compounds 4 and 7 (PG14N, PG17N) show potent and selective allosteric inhibition at hMC5R with IC 50 values of 38 +/- 3 nM and 58 +/- 6 nM, respectively. Compound 9 will be used to further investigate and more clearly understand the physiological roles played by the MC5 receptor in humans and other animals.
...
PMID:Design and microwave-assisted synthesis of novel macrocyclic peptides active at melanocortin receptors: discovery of potent and selective hMC5R receptor antagonists. 1841 16