Discovery of Naturally Occurring Splice Variants of the Rat Histamine H3Receptor That Act as Dominant-Negative Isoforms

2006 ◽  
Vol 69 (4) ◽  
pp. 1194-1206 ◽  
Author(s):  
Remko A. Bakker ◽  
Adrian Flores Lozada ◽  
André van Marle ◽  
Fiona C. Shenton ◽  
Guillaume Drutel ◽  
...  
Cell Reports ◽  
2018 ◽  
Vol 25 (6) ◽  
pp. 1577-1592.e6 ◽  
Author(s):  
Marianna Aprile ◽  
Simona Cataldi ◽  
Maria Rosaria Ambrosio ◽  
Vittoria D’Esposito ◽  
Koini Lim ◽  
...  

Development ◽  
2000 ◽  
Vol 127 (9) ◽  
pp. 1845-1855 ◽  
Author(s):  
D.P. Rice ◽  
T. Aberg ◽  
Y. Chan ◽  
Z. Tang ◽  
P.J. Kettunen ◽  
...  

Mutations in the FGFR1-FGFR3 and TWIST genes are known to cause craniosynostosis, the former by constitutive activation and the latter by haploinsufficiency. Although clinically achieving the same end result, the premature fusion of the calvarial bones, it is not known whether these genes lie in the same or independent pathways during calvarial bone development and later in suture closure. We have previously shown that Fgfr2c is expressed at the osteogenic fronts of the developing calvarial bones and that, when FGF is applied via beads to the osteogenic fronts, suture closure is accelerated (Kim, H.-J., Rice, D. P. C., Kettunen, P. J. and Thesleff, I. (1998) Development 125, 1241–1251). In order to investigate further the role of FGF signalling during mouse calvarial bone and suture development, we have performed detailed expression analysis of the splicing variants of Fgfr1-Fgfr3 and Fgfr4, as well as their potential ligand Fgf2. The IIIc splice variants of Fgfr1-Fgfr3 as well as the IIIb variant of Fgfr2 being expressed by differentiating osteoblasts at the osteogenic fronts (E15). In comparison to Fgf9, Fgf2 showed a more restricted expression pattern being primarily expressed in the sutural mesenchyme between the osteogenic fronts. We also carried out a detailed expression analysis of the helix-loop-helix factors (HLH) Twist and Id1 during calvaria and suture development (E10-P6). Twist and Id1 were expressed by early preosteoblasts, in patterns that overlapped those of the FGF ligands, but as these cells differentiated their expression dramatically decreased. Signalling pathways were further studied in vitro, in E15 mouse calvarial explants. Beads soaked in FGF2 induced Twist and inhibited Bsp, a marker of functioning osteoblasts. Meanwhile, BMP2 upregulated Id1. Id1 is a dominant negative HLH thought to inhibit basic HLH such as Twist. In Drosophila, the FGF receptor FR1 is known to be downstream of Twist. We demonstrated that in Twist(+/)(−) mice, FGFR2 protein expression was altered. We propose a model of osteoblast differentiation integrating Twist and FGF in the same pathway, in which FGF acts both at early and late stages. Disruption of this pathway may lead to craniosynostosis.


FEBS Letters ◽  
2013 ◽  
Vol 587 (12) ◽  
pp. 1749-1753 ◽  
Author(s):  
Floriane M. Imhoff ◽  
Dee Yang ◽  
Suneeth F. Mathew ◽  
Andrew N. Clarkson ◽  
Yui Kawagishi ◽  
...  

PLoS ONE ◽  
2016 ◽  
Vol 11 (9) ◽  
pp. e0163328 ◽  
Author(s):  
Shaorong Zhao ◽  
Wei Liu ◽  
Yinghui Li ◽  
Pengjiang Liu ◽  
Shufang Li ◽  
...  

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 995-995
Author(s):  
Marrit Meier ◽  
Monique L. Den Boer ◽  
Jules P.P. Meijerink ◽  
Monique Passier ◽  
Elisabeth R. Van Wering ◽  
...  

Abstract Children with T-lineage Acute Lymphoblastic Leukemia (T-ALL) have a higher relapse-risk and are in-vitro more resistant to therapeutic drugs compared to ALL patients with a precursor-B phenotype. Cellular resistance to anti-cancer agents has previously shown to be associated with failure of P53 family member signaling by abrogation of P53 function due to loss-of-function mutations or dominant-negative inhibition by isoforms of P73 lacking (part of) the N-terminal transactivation domain (P73ΔEX2, P73ΔEX2/3, ΔN-P73 and ΔN’-P73). Since p53 mutations are not commonly found in T-ALL, we investigated the expression levels of p73 splice variants in relation to drug resistance in children with T-ALL. Splice variants were quantitatively measured at the mRNA level in leukemic cells of 55 T-ALL patients and mononuclear cells of 12 non-leukemic controls. TA-p73 (transactivation competent), p73Δex2, p73Δex2/3, ΔN-p73 and ΔN’-p73 were all found to be present at a relatively higher mRNA level in T-ALL patients than controls (P < 0.05 for all), suggesting that expression of the TP73 gene is deregulated in T-ALL. Resistance of T-ALL cells to the DNA damaging drug daunorubicin correlated with mRNA levels of the dominant-negative variants of p73, i.e. ΔN-p73 and ΔN’-p73 (Rs = 0.38, P = 0.03). In contrast, expression of none of the variants, including ΔN-p73 and ΔN’-p73, was related to resistance of T-ALL cells to non-DNA damaging drugs (prednisolone, vincristine and L-asparaginase). In conclusion, high expression of ΔN-p73 and ΔN’-p73 variants possibly contributes to resistance to DNA damaging drugs in childhood T-ALL.


2007 ◽  
Vol 38 (1) ◽  
pp. 91-98 ◽  
Author(s):  
Henk Russcher ◽  
Virgil A S H Dalm ◽  
Frank H de Jong ◽  
Albert O Brinkmann ◽  
Leo J Hofland ◽  
...  

The glucocorticoid receptor (GR) is widely expressed in various tissues throughout the human body. At least three different 3′-splice variants of the GR have been reported: GR-α, which is functionally active; GR-β, which is a dominant negative inhibitor of GR-α function; and GR-P, which is thought to activate the function of GR-α. At least seven different variants for exon 1 exist, 1A–1F and 1H, each with its own promoter. In this study, we explored if tissue-specific splicing of the 3′-end variants of the GR is influenced by alternative promoter usage. cDNAs of different tissues and cell lines were used to investigate which part of transcripts carrying each of the three major variants for exons 1, 1A, 1B, or 1C, encodes for the splice variants GR-α, GR-β, and GR-P. Our data demonstrate that the expression of GR-α is preferentially regulated by promoter 1C and that for the expression of GR-P promoter 1B is predominantly used. This indicates that regulation of GR splice variants could partly occur through selective use of the multiple promoters, and that this is another way to sensitize cells and tissues to the different activities of the GR isoforms.


2008 ◽  
Vol 414 (1) ◽  
pp. 121-131 ◽  
Author(s):  
Richard M. van Rijn ◽  
André van Marle ◽  
Paul L. Chazot ◽  
Ellen Langemeijer ◽  
Yongjun Qin ◽  
...  

The H4R (histamine H4 receptor) is the latest identified member of the histamine receptor subfamily of GPCRs (G-protein-coupled receptors) with potential functional implications in inflammatory diseases and cancer. The H4R is primarily expressed in eosinophils and mast cells and has the highest homology with the H3R. The occurrence of at least twenty different hH3R (human H3R) isoforms led us to investigate the possible existence of H4R splice variants. In the present paper, we report on the cloning of the first two alternatively spliced H4R isoforms from CD34+ cord blood-cell-derived eosinophils and mast cells. These H4R splice variants are localized predominantly intracellularly when expressed recombinantly in mammalian cells. We failed to detect any ligand binding, H4R–ligand induced signalling or constitutive activity for these H4R splice variants. However, when co-expressed with full-length H4R [H4R(390) (H4R isoform of 390 amino acids)], the H4R splice variants have a dominant negative effect on the surface expression of H4R(390). We detected H4R(390)–H4R splice varianthetero-oligomers by employing both biochemical (immunoprecipitation and cell-surface labelling) and biophysical [time-resolved FRET (fluorescence resonance energy transfer)] techniques. mRNAs encoding the H4R splice variants were detected in various cell types and expressed at similar levels to the full-length H4R(390) mRNA in, for example, pre-monocytes. We conclude that the H4R splice variants described here have a dominant negative effect on H4R(390) functionality, as they are able to retain H4R(390) intracellularly and inactivate a population of H4R(390), presumably via hetero-oligomerization.


2013 ◽  
Vol 4 (1-2) ◽  
pp. 26-38 ◽  
Author(s):  
M. Peng ◽  
Z. Yang ◽  
H. Zhang ◽  
L. Jaafar ◽  
G. Wang ◽  
...  

2010 ◽  
Vol 104 (1) ◽  
pp. 439-448 ◽  
Author(s):  
Donald Beqollari ◽  
Paul J. Kammermeier

Metabotropic glutamate receptors (mGluRs) form covalently linked homodimers and contain large, N-terminal extracellular ligand binding, “venus fly trap” (VFT) domains. These domains, when expressed separately, are secreted as disulfide linked dimers and can dimerize with full-length receptors. mGluR splice variants have been described that contain only this domain, but the consequences of their interaction on receptor signaling have not been explored. Here it is shown that an mGluR1 mutant containing only the VFT is retained on the cell surface when a full-length receptor is co-expressed. Further, when expressed in rat superior cervical ganglion (SCG) neurons and modulation of native calcium currents is used as an assay for receptor activity, the VFT acts as a dominant negative with respect to mGluR1 signaling. Although full-length mGluR1 and mGluR5 are not known to heterodimerize, the mGluR5 VFT partially occludes mGluR1 signaling and the mGluR1 VFT potently occludes mGluR5 signaling in SCG neurons. In addition, an mGluR1 point mutant, mGluR1 C140G, which cannot covalently dimerize, functions like the wild-type receptor when expressed alone. The C140G mutant is inhibited by the mGluR1 VFT construct but does not retain the mGluR1 VFT on the cell surface, suggesting that the loss of C140 renders the interaction reversible. Finally, a peptide designed to disrupt mGluR1 dimerization reduced signaling through the C140G mutant receptor, but only when applied intracellularly for several hours, indicating that loss of signaling requires disruption of dimerization prior to plasma membrane insertion.


Retrovirology ◽  
2012 ◽  
Vol 9 (1) ◽  
pp. 86 ◽  
Author(s):  
Sarah Welbourn ◽  
Eri Miyagi ◽  
Tommy E White ◽  
Felipe Diaz-Griffero ◽  
Klaus Strebel

Sign in / Sign up

Export Citation Format

Share Document