Post-secretory processing of peptide signals: a novel mechanism for the regulation of peptide hormone receptors

1997 ◽  
Vol 25 (3) ◽  
pp. 1011-1014 ◽  
Author(s):  
A. I. Smith ◽  
I. J. Clarke ◽  
R. A. Lew
Keyword(s):  
Hormone Receptors ◽  
Peptide Hormone ◽  
Peptide Signals ◽  
Peptide Hormone Receptors

Dual actions of lanthanides on ACTH-inhibited leak K+ channels

2002 ◽  
Vol 282 (6) ◽  
pp. E1255-E1266 ◽  
Author(s):  
John J. Enyeart ◽  
Lin Xu ◽  
Judith A. Enyeart
Keyword(s):  
Binding Sites ◽  
Hormone Receptors ◽  
Peptide Hormone ◽  
Receptor Activation ◽  
Zona Fasciculata ◽  
Ionic Radii ◽  
Whole Cell Patch Clamp ◽  
Acth Receptor ◽  
Dependent Inhibition ◽  
Peptide Hormone Receptors

Bovine adrenal zona fasciculata cells express background K+ channels ( I ACchannels) whose activity is potently inhibited by ACTH. In whole cell patch clamp recordings, it was discovered that the trivalent lanthanides (Ln3+s) lanthanum and ytterbium interact with two binding sites to modulate K+ flow through these channels. Despite large differences in ionic radii, these Ln3+s inhibited I AC channels half-maximally with IC50 values near 50 μM. In addition, these Ln3+s blocked and reversed ACTH-mediated inhibition of I AC K+ channels at similar concentrations. The Ln3+s did not alter inhibition of I AC by angiotensin II or cAMP. Ln3+-induced uncoupling of ACTH receptor activation from I AC inhibition was prevented by raising the external Ca2+ concentration from 2 to 10 mM. The divalent cation Ni2+ (500 μM) also blocked ACTH-dependent inhibition of I AC through a Ca2+-sensitive mechanism. The results are consistent with a model in which Ln3+s produce opposing actions on I AC K+ currents through two separate binding sites. In addition to directly inhibiting I AC, Ln3+s (and Ni2+) bind with high affinity to a Ca2+-selective site associated with the ACTH receptor. By displacing Ca2+ from this site, Ln3+s prevent ACTH from binding and accelerate its dissociation. These results identify Ln3+s as a relatively potent group of noncompetitive ACTH receptor antagonists. Allosteric actions of trivalent and divalent metal cations on hormone binding, mediated through Ca2+-specific sites, may be common to a variety of peptide hormone receptors.

Peptide Hormone Receptors

1977 ◽  
Vol 39 (1) ◽  
pp. 529-557 ◽  
Author(s):  
K J Catt ◽  
M L Dufau
Keyword(s):  
Hormone Receptors ◽  
Peptide Hormone ◽  
Peptide Hormone Receptors

scholarly journals EXPRESSION OF STEROID AND PEPTIDE HORMONE RECEPTORS, METABOLIC ENZYMES AND EMT-RELATED GENES IN PROSTATE TUMORS IN RELATION TO THE PRESENCE OF THE TMPRSS2/ERG FUSION

2018 ◽  
Vol 40 (2) ◽  
pp. 101-108 ◽  
Author(s):  
G V Gerashchenko ◽  
L V Mevs ◽  
L I Chashchina ◽  
M V Pikul ◽  
O P Gryzodub ◽  
...  
Keyword(s):  
Gene Expression ◽  
Prostate Cancer ◽  
Expression Pattern ◽  
Hormone Receptors ◽  
Expression Profiles ◽  
Gene Expression Profiles ◽  
Peptide Hormone ◽  
Metabolic Enzymes ◽  
Prostate Tumors ◽  
Peptide Hormone Receptors

Aim: To analyze an expression pattern of the steroid and peptide hormone receptors, metabolic enzymes and EMT-related genes in prostate tumors in relation to the presence of the TMPRSS2/ERG fusion; and to examine a putative correlation between gene expression and clinical characteristics, to define the molecular subtypes of prostate cancer. Materials and Methods: The relative gene expression (RE) of 33 transcripts (27 genes) and the presence/absence of the TMPRSS2/ERG fusion were analyzed by a quantitative PCR. 37 prostate cancer tissues (T) paired with conventionally normal prostate tissue (CNT) and 21 samples of prostate adenomas were investigated. RE changes were calculated, using different protocols of statistics. Results: We demonstrated differences in RE of seven genes between tumors and CNT, as was calculated, using the 2−ΔCT model and the Wilcoxon matched paired test. Five genes (ESR1, KRT18, MKI67, MMP9, PCA3) showed altered expression in adenocarcinomas, in which the TMPRSS2/ERG fusion was detected. Two genes (INSR, isoform B and HOTAIR) expressed differently in tumors without fusion. Comparison of the gene expression pattern in adenomas, CNT and adenocarcinomas demonstrated that in adenocarcinomas, bearing the TMPRSS2/ ERG fusion, genes KRT18, PCA3, and SCHLAP1 expressed differently. At the same time, we detected differences in RE of AR (isoform 2), MMP9, PRLR and HOTAIR in adenocarcinomas without the TMPRSS2/ERG fusion. Two genes (ESR1 and SRD5A2) showed differences in RE in both adenocarcinoma groups. Fourteen genes, namely AR (isoforms 1 and 2), CDH1, OCLN, NKX3-1, XIAP, GCR (ins AG), INSR (isoform A), IGF1R, IGF1R tr, PRLR, PRL, VDR and SRD5A2 showed correlation between RE and tumor stage. RE of four genes (CDH2, ESR2, VDR and SRD5A2) correlated with differentiation status of tumors (Gleason score). Using the K-means clustering, we could cluster adenocarcinomas in three groups, according to gene expression profiles. A specific subtype of prostate tumors is characterized by the activated ERG signaling, due to the presence of TMPRSS2/ERG fusion, and also by high levels of the androgen receptor, prolactin, IGF, INSR and PCA3. Conclusions: We have found the specific differences in expression of the steroid and peptide hormone receptors, metabolic enzymes and EMT-related genes, depending on the presence/absence of the TMPRSS2/ERG fusion in prostate adenocarcinomas, CNT and adenomas. We showed three different gene expression profiles of prostate adenocarcinomas. One of them is characteristic for adenocarcinomas with the TMPRSS2/ERG fusion. Further experiments are needed to confirm these data in a larger cohort of patients.

scholarly journals Mechanistic insight into a peptide hormone signaling complex mediating floral organ abscission

eLife ◽  
2016 ◽  
Vol 5 ◽  
Author(s):  
Julia Santiago ◽  
Benjamin Brandt ◽  
Mari Wildhagen ◽  
Ulrich Hohmann ◽  
Ludwig A Hothorn ◽  
...  
Keyword(s):  
Hormone Receptors ◽  
Peptide Hormone ◽  
Binding Pocket ◽  
Binding Mode ◽  
Floral Organ ◽  
Activation Mechanism ◽  
Signaling Complex ◽  
Floral Abscission ◽  
Peptide Hormone Receptors ◽  
Insight Into

Plants constantly renew during their life cycle and thus require to shed senescent and damaged organs. Floral abscission is controlled by the leucine-rich repeat receptor kinase (LRR-RK) HAESA and the peptide hormone IDA. It is unknown how expression of IDA in the abscission zone leads to HAESA activation. Here we show that IDA is sensed directly by the HAESA ectodomain. Crystal structures of HAESA in complex with IDA reveal a hormone binding pocket that accommodates an active dodecamer peptide. A central hydroxyproline residue anchors IDA to the receptor. The HAESA co-receptor SERK1, a positive regulator of the floral abscission pathway, allows for high-affinity sensing of the peptide hormone by binding to an Arg-His-Asn motif in IDA. This sequence pattern is conserved among diverse plant peptides, suggesting that plant peptide hormone receptors may share a common ligand binding mode and activation mechanism.

Peptide Hormone Receptors

1991 ◽  
pp. 143-157 ◽  
Author(s):  
J. Lloyd ◽  
R. Tibolt ◽  
G. V. Childs
Keyword(s):  
Hormone Receptors ◽  
Peptide Hormone ◽  
Peptide Hormone Receptors
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