Functional domains of the C-terminus of the rat angiotensin AT1A receptor

1995 ◽  
Vol 291 (2) ◽  
pp. 135-141 ◽  
Author(s):  
Anthony J. Balmforth ◽  
Alison J. Lee ◽  
Balwinder P.S. Bajaj ◽  
Catherine J. Dickinson ◽  
Philip Warburton ◽  
...  
Keyword(s):  
Functional Domains ◽  
C Terminus ◽  
At1a Receptor

scholarly journals Fip1 Regulates the Activity of Poly(A) Polymerase through Multiple Interactions

2001 ◽  
Vol 21 (6) ◽  
pp. 2026-2037 ◽  
Author(s):  
Steffen Helmling ◽  
Alexander Zhelkovsky ◽  
Claire L. Moore
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Amino Acids ◽  
Rna Binding ◽  
Physiological Function ◽  
Regulatory Function ◽  
Functional Domains ◽  
Essential Component ◽  
C Terminus ◽  
Mrna Precursor ◽  
Multiple Interactions

ABSTRACT Fip1 is an essential component of the Saccharomyces cerevisiae polyadenylation machinery and the only protein known to interact directly with poly(A) polymerase (Pap1). Its association with Pap1 inhibits the extension of an oligo(A) primer by limiting access of the RNA substrate to the C-terminal RNA binding domain (C-RBD) of Pap1. We present here the identification of separate functional domains of Fip1. Amino acids 80 to 105 are required for binding to Pap1 and for the inhibition of Pap1 activity. This region is also essential for viability, suggesting that Fip1-mediated repression of Pap1 has a crucial physiological function. Amino acids 206 to 220 of Fip1 are needed for the interaction with the Yth1 subunit of the complex and for specific polyadenylation of the cleaved mRNA precursor. A third domain within amino acids 105 to 206 helps to limit RNA binding at the C-RBD of Pap1. Our data demonstrate that the C terminus of Fip1 is required to relieve the Fip1-mediated repression of Pap1 in specific polyadenylation. In the absence of this domain, Pap1 remains in an inhibited state. These findings show that Fip1 has a crucial regulatory function in the polyadenylation reaction by controlling the activity of poly(A) tail synthesis through multiple interactions within the polyadenylation complex.

scholarly journals Analysis of Functional Domains of theEnterococcus faecalis Pheromone-Induced Surface Protein Aggregation Substance

2001 ◽  
Vol 183 (19) ◽  
pp. 5659-5667 ◽  
Author(s):  
C. M. Waters ◽  
G. M. Dunny
Keyword(s):  
Cell Surface ◽  
High Efficiency ◽  
Cell Surface Hydrophobicity ◽  
Surface Protein ◽  
Cell Aggregation ◽  
Surface Hydrophobicity ◽  
Host Cells ◽  
Functional Domains ◽  
Aggregation Substance ◽  
C Terminus

ABSTRACT Pheromone-inducible aggregation substance (AS) proteins ofEnterococcus faecalis are essential for high-efficiency conjugation of the sex pheromone plasmids and also serve as virulence factors during host infection. A number of different functions have been attributed to AS in addition to bacterial cell aggregation, including adhesion to host cells, adhesion to fibrin, increased cell surface hydrophobicity, resistance to killing by polymorphonuclear leukocytes and macrophages, and increased vegetation size in an experimental endocarditis model. Relatively little information is available regarding the structure-activity relationship of AS. To identify functional domains, a library of 23 nonpolar 31-amino-acid insertions was constructed in Asc10, the AS encoded by the plasmid pCF10, using the transposons TnlacZ/in and TnphoA/in. Analysis of these insertions revealed a domain necessary for donor-recipient aggregation that extends further into the amino terminus of the protein than previously reported. In addition, insertions in the C terminus of the protein also reduced aggregation. As expected, the ability to aggregate correlates with efficient plasmid transfer. The results also indicated that an increase in cell surface hydrophobicity resulting from AS expression is not sufficient to mediate bacterial aggregation.

scholarly journals Genetic dissection of functional domains within the avian erythroblastosis virus v-erbA oncogene.

1988 ◽  
Vol 8 (10) ◽  
pp. 4510-4517 ◽  
Author(s):  
M L Privalsky ◽  
P Boucher ◽  
A Koning ◽  
C Judelson
Keyword(s):  
Hormone Receptors ◽  
Target Genes ◽  
Thyroid Hormone Receptor ◽  
Steroid Hormone Receptors ◽  
Site Directed Mutagenesis ◽  
Functional Domains ◽  
Genetic Dissection ◽  
Coding Region ◽  
C Terminus ◽  
Avian Erythroblastosis Virus

The avian erythroblastosis virus v-erbA locus potentiates the oncogenic transformation of erythroid and fibroblast cells and is derived from a host cell gene encoding a thyroid hormone receptor. We report here the use of site-directed mutagenesis to identify and characterize functional domains within the v-erbA protein. Genetic lesions introduced into a putative hinge region or at the extreme C-terminus of the v-erbA coding domain had no significant effect on the biological activity of this polypeptide. In contrast, mutations introduced within the cysteine-lysine-arginine-rich center of the v-erbA coding region, a DNA-binding domain in the thyroid and steroid hormone receptors, abolished or severely compromised the ability of the viral protein to function. Our results suggest that the mechanism of action of the v-erbA protein in establishing the neoplastic phenotype is closely related to its ability to interact with DNA, presumably thereby altering expression of host target genes by either mimicking or interfering with the action of the normal c-erbA gene product.

Josephin domain-containing proteins from a variety of species are active de-ubiquitination enzymes

2007 ◽  
Vol 388 (9) ◽  
pp. 973-978 ◽  
Author(s):  
Nikolay Tzvetkov ◽  
Peter Breuer
Keyword(s):  
Plasmodium Falciparum ◽  
Enzyme Activity ◽  
Neurodegenerative Disease ◽  
Spinocerebellar Ataxia ◽  
Spinocerebellar Ataxia Type ◽  
Functional Domains ◽  
Spinocerebellar Ataxia Type 3 ◽  
C Terminus ◽  
Human Proteins ◽  
Type 3

Abstract The neurodegenerative disease spinocerebellar ataxia type 3 (SCA3) is caused by the presence of an extended polyglutamine stretch (polyQ) in the unstructured C-terminus of the human ataxin-3 (AT3) protein. The structured N-terminal Josephin domain (JD) of AT3 is conserved within a novel family of potential ubiquitin proteases, the JD-containing proteins, which are sub-divided into two groups termed ataxins and Josephins. These AT3 orthologs are encoded by the genomes of organisms ranging from Plasmodium falciparum to humans, with most species possessing more than one homolog. While Josephins consist of JDs alone, ataxins contain additional functional domains that may influence their enzyme activity. Here, we show that the enzyme activity of human AT3 (hAT3) is not affected by the length of polyQ in its C-terminus, even when it is in the range associated with SCA3. We also show that JDs of all human proteins with homology to AT3 and its homologs from various species possess de-ubiquitination activity. These results establish JD-containing proteins as a novel family of active de-ubiquitination enzymes with wide phylogenic distribution.

scholarly journals Identification of protein kinase C phosphorylation sites in the angiotensin II (AT1A) receptor

1999 ◽  
Vol 343 (3) ◽  
pp. 637-644 ◽  
Author(s):  
Hongwei QIAN ◽  
Luisa PIPOLO ◽  
Walter G. THOMAS
Keyword(s):  
Protein Kinase C ◽  
Angiotensin Ii ◽  
Protein Kinase ◽  
Single Mutation ◽  
Wild Type ◽  
Receptor Phosphorylation ◽  
Kinase C ◽  
C Terminus ◽  
At1a Receptor ◽  
Mutant Receptors

Protein kinase C (PKC) phosphorylates the C-terminus of the type 1 angiotensin II receptor (AT1), although the exact site(s) of phosphorylation are unidentified. In the present study, we examined the phosphorylation of epitope-tagged wild-type AT1A receptors, transiently expressed in Chinese hamster ovary K1 cells, in response to angiotensin II (AngII) and following selective activation and inhibition of PKC. This phosphorylation was compared with mutant receptors where C-terminal serine residues (Ser331, Ser338 and Ser348) within three putative PKC consensus sites were replaced with alanine, either individually or in combination. Stimulation by AngII or the phorbol ester PMA to activate PKC induced an increase in phosphorylation of the wild-type AT1A receptor, which was prevented by truncation of the receptor C-terminus to remove the last 34 amino acids, including Ser331, Ser338 and Ser348. Whereas single alanine mutation (Ser331Ala, Ser338Ala and Ser348Ala) resulted in decreased receptor phosphorylation, no single mutant completely inhibited either AngII- or PMA-induced phosphorylation. Combined mutation of the three PKC consensus sites caused an ≈ 70% reduction in PMA-mediated phosphorylation. The ≈ 60% reduction in AngII (1 μM)-induced phosphorylation of this triple mutant and the partial inhibition of wild-type receptor phosphorylation by bisindolylmaleimide, a specific PKC inhibitor, suggest a significant contribution of PKC to agonist-stimulated regulation. The ratio of PKC to total receptor phosphorylation was greatest at low doses of AngII (1 nM), consistent with the idea that PKC phosphorylates and regulates receptor function at low levels of stimulation, whereas phosphorylation by other kinases is more prevalent at high levels of agonist stimulation. To determine if a single PKC site is favoured when the contribution of PKC varies, the phosphorylation of wild-type and mutant receptors was examined over a range of AngII concentrations (0, 1, 10 and 100 nM). At all AngII concentrations, single mutation of Ser331, Ser338 or Ser348 was incapable of completely preventing receptor phosphorylation, suggesting no clear preference for PKC consensus-site utilization. Together, these results indicate a redundancy in PKC phosphorylation of the AT1A receptor, whereby all three consensus sites are utilized to some degree following homologous (AngII) and heterologous (PMA) stimulation. The contribution of PKC phosphorylation to receptor regulation is unclear, but multiple PKC phosphorylation of the AT1A receptor may allow independent and/or complementary events to occur at the three separate sites of the C-terminus.

Identification of the topology and functional domains of PAQR10

2012 ◽  
Vol 443 (3) ◽  
pp. 643-653 ◽  
Author(s):  
Ting Jin ◽  
Daqian Xu ◽  
Qiurong Ding ◽  
Yixuan Zhang ◽  
Chenqian Mao ◽  
...  
Keyword(s):  
Golgi Apparatus ◽  
Integral Membrane Protein ◽  
Proximal Region ◽  
Functional Domains ◽  
Golgi Localization ◽  
Erk Phosphorylation ◽  
C Terminus ◽  
Extracellular Signal ◽  
N Terminus ◽  
Membrane Proximal Region

PAQR10 (progestin and adipoQ receptor 10) is a Golgi-localized protein that is able to enhance the retention and activation of Ras proteins in the Golgi apparatus, subsequently leading to a sustained ERK (extracellular-signal-regulated kinase) signalling. However, little is known about the topology and functional domains of PAQR10. In the present study, we extensively dissected and analysed the structure of PAQR10. The topology analysis reveals that PAQR10 is an integral membrane protein with its N-terminus facing the cytosol. Multiple domains, including the membrane-proximal region at the N-terminus, the membrane-proximal region at the C-terminus and the three loops facing the cytosol, were found to be required for PAQR10 to reside in the Golgi apparatus, to stimulate ERK phosphorylation and to tether Ras to the Golgi apparatus. Furthermore, when PAQR10 was artificially forced to be expressed in the endoplasmic reticulum, it could neither mobilize Ras to the Golgi apparatus nor increase ERK phosphorylation. Finally, the PAQR10 mutants that lost Golgi localization failed to promote differentiation of PC12 cells. Collectively, the results of the present study indicate that Golgi localization is indispensable for PAQR10 to implement its regulatory functions in the Ras signalling cascade.

scholarly journals Identification of Key Functional Domains in the C Terminus of the K+-Cl– Cotransporters

2006 ◽  
Vol 281 (23) ◽  
pp. 15959-15969 ◽  
Author(s):  
Marc J. Bergeron ◽  
Édith Gagnon ◽  
Luc Caron ◽  
Paul Isenring
Keyword(s):  
Functional Domains ◽  
C Terminus

Genetic dissection of functional domains within the avian erythroblastosis virus v-erbA oncogene

1988 ◽  
Vol 8 (10) ◽  
pp. 4510-4517
Author(s):  
M L Privalsky ◽  
P Boucher ◽  
A Koning ◽  
C Judelson
Keyword(s):  
Hormone Receptors ◽  
Target Genes ◽  
Thyroid Hormone Receptor ◽  
Steroid Hormone Receptors ◽  
Site Directed Mutagenesis ◽  
Functional Domains ◽  
Genetic Dissection ◽  
Coding Region ◽  
C Terminus ◽  
Avian Erythroblastosis Virus

The avian erythroblastosis virus v-erbA locus potentiates the oncogenic transformation of erythroid and fibroblast cells and is derived from a host cell gene encoding a thyroid hormone receptor. We report here the use of site-directed mutagenesis to identify and characterize functional domains within the v-erbA protein. Genetic lesions introduced into a putative hinge region or at the extreme C-terminus of the v-erbA coding domain had no significant effect on the biological activity of this polypeptide. In contrast, mutations introduced within the cysteine-lysine-arginine-rich center of the v-erbA coding region, a DNA-binding domain in the thyroid and steroid hormone receptors, abolished or severely compromised the ability of the viral protein to function. Our results suggest that the mechanism of action of the v-erbA protein in establishing the neoplastic phenotype is closely related to its ability to interact with DNA, presumably thereby altering expression of host target genes by either mimicking or interfering with the action of the normal c-erbA gene product.

Sign in / Sign up

Export Citation Format

Share Document