Characterization of the interaction between the transcription factors human polyamine modulated factor (PMF-1) and NF-E2-related factor 2 (Nrf-2) in the transcriptional regulation of the spermidine/spermine N1-acetyltransferase (SSAT) gene

2001 ◽  
Vol 355 (1) ◽  
pp. 45-49 ◽  
Author(s):  
Yanlin WANG ◽  
Wendy DEVEREUX ◽  
Tracy Murray STEWART ◽  
Robert A. CASERO
Keyword(s):  
Transcriptional Regulation ◽  
Transcription Factors ◽  
Leucine Zipper ◽  
Coiled Coil ◽  
Protein Family ◽  
Related Factor ◽  
Polyamine Analogues ◽  
Coiled Coil Region

Polyamines and polyamine analogues have been demonstrated to modulate the transcription of various genes. Spermidine/spermine N1-acetyltransferase (SSAT) is transcriptionally regulated through the interaction of at least two trans-acting transcription factors, NF-E2-related factor 2 (Nrf-2) and PMF-1 (polyamine modulated factor-1). Nrf-2has previously been shown to regulate transcription of other genes through interactions between its C-terminal leucine zipper and the leucine-zipper region of other members of the small Maf protein family (the term ‘Maf’ is derived from musculoaponeurotic-fibrosarcoma virus). Here it is demonstrated that the interaction between Nrf-2 and PMF-1 is mediated through the binding of the leucine-zipper region of Nrf-2 and a C-terminal coiled-coil region of PMF-1 that does not contain a leucine zipper. Mutations that interrupt either the leucine zipper of Nrf-2 or the coiled-coil region of PMF-1 are demonstrated to alter the ability of these factors to interact, thus their ability to regulate the transcription of the SSAT gene is lost.

Cloning and characterization of the mouse polyamine-modulatedfactor-1 (mPMF-1) gene: an alternatively spliced homologue of the human transcription factor

2001 ◽  
Vol 359 (2) ◽  
pp. 387-392 ◽  
Author(s):  
Yanlin WANG ◽  
Wendy DEVEREUX ◽  
Patrick M. WOSTER ◽  
Robert A. CASERO
Keyword(s):  
Amino Acids ◽  
Transcription Factor ◽  
Transcriptional Activation ◽  
Splice Variants ◽  
Coiled Coil ◽  
Human Protein ◽  
Related Factor ◽  
Polyamine Analogues ◽  
Coiled Coil Region ◽  
Alternatively Spliced

The natural polyamines and their analogues have been implicated in transcriptional regulation of specific genes. Human polyamine-modulated factor-1 (hPMF-1) was the first polyamine-responsive transcription factor identified. Here the mouse homologue of the hPMF-1 gene is described. Interestingly, the mouse gene (mPMF-1) codes for two alternatively spliced mRNAs. Both of the mouse splice variants, mPMF-1S and mPMF-1L, possess C-terminal coiled-coil domains nearly identical to that found in hPMF-1 and are highly homologous with the human protein. The C-terminal coiled-coil structure is necessary for transcriptional activation. However, the shorter protein, mPMF-1S, does not contain an N-terminal coiled-coil region as do both hPMF-1 and the longer mPMF-1L. mPMF-1L mRNA codes for a protein of 202 amino acids, 37 amino acids longer than the human protein. By contrast, mPMF-1S codes for only 133 amino acids, as a result of two exons being omitted compared with mPMF-1L. Both mouse transcription factors can interact with Nrf-2 (nuclear factor-E2-related factor 2), the normal partner of hPMF-1, substantiating the importance of the C-terminal coiled-coil region responsible for this interaction. Finally, the expression of mPMF-1 is induced when mouse M1 myeloid leukaemia cells are exposed to polyamine analogues, suggesting control similar to that observed for the hPMF-1.

scholarly journals 2066 Functional characterization of mutant BRCA1

2018 ◽  
Vol 2 (S1) ◽  
pp. 13-13
Author(s):  
John Barrows ◽  
David Long
Keyword(s):  
Functional Characterization ◽  
Coiled Coil ◽  
Wild Type ◽  
Coiled Coil Region ◽  
Egg Extracts ◽  
Study Population ◽  
Xenopus Egg ◽  
Xenopus Egg Extracts

OBJECTIVES/SPECIFIC AIMS: The objective of this work is to determine the mechanistic consequences of BRCA1 mutants in inter-strand crosslink (ICL) repair. METHODS/STUDY POPULATION: Our lab uses Xenopus egg extracts to study ICL repair. These extracts can be depleted of endogenous BRCA1 by immunoprecipitation. The goal of this work is to rescue endogenous depletion with in vitro translated, wild type BRCA1. Once achieved, we can supplement the depleted extract with BRCA1 mutants to access their function in ICL repair. RESULTS/ANTICIPATED RESULTS: We hypothesize that the BRCT and RING domain mutations will abrogate ICL repair, while mutations in the coiled coil region will not affect repair. DISCUSSION/SIGNIFICANCE OF IMPACT: These findings will have an immense impact on the understanding of BRCA1 domains. Importantly these results will spur personalized therapy of BRCA1 mutants by showing which domains are sensitive to cross-linking agents.

scholarly journals Leucine-zipper-mediated homo- and hetero-dimerization of GIT family p95-ARF GTPase-activating protein, PIX-, paxillin-interacting proteins 1 and 2

2003 ◽  
Vol 372 (2) ◽  
pp. 391-398 ◽  
Author(s):  
Simona PARIS ◽  
Renato LONGHI ◽  
Paolo SANTAMBROGIO ◽  
Ivan de CURTIS
Keyword(s):  
Leucine Zipper ◽  
Coiled Coil ◽  
Actin Dynamics ◽  
Exchange Factor ◽  
Gtpase Activating Proteins ◽  
Rac Gtpases ◽  
Coiled Coil Region ◽  
The Family ◽  
G Protein Coupled ◽  
Adp Ribosylation Factor

ADP-ribosylation factor GTPase-activating proteins (ARFGAPs) of the G-protein-coupled receptor kinase interactor 1/p95 paxillin kinase linker/p95-ARFGAP Pak-interacting exchange factor paxillin-binding protein (APP)-1 family are multidomain proteins, which interact functionally with both ARF and Rac GTPases. These proteins are involved in the dynamic reorganization of adhesion and the cytoskeleton during cell motility. Our previous work [Di Cesare, Paris, Albertinazzi, Dariozzi, Andersen, Mann, Longhi and de Curtis (2000) Nat. Cell Biol. 2, 521–530] has pointed out a role for p95-APP1 in the regulation of ARF6-mediated membrane recycling. These proteins include different domains, and are capable of interacting stably with proteins that are supposed to play a role in the regulation of actin dynamics and adhesion. They contain a coiled-coil region comprising a putative leucine zipper, predicted to be involved in dimerization. In the present study, we have investigated the possibility that these proteins form dimers. Our results show that p95-APP1 forms homodimers and may also form heterodimers with the other member of the family, p95 paxillin kinase linker/p95-APP2. Both homo- and heterodimerization are disrupted by mutation of two leucine residues in the coiled-coil region of p95-APP1. The N-terminal portion of p95-APP1, including the ARFGAP domain, three ankyrin repeats and the Pak-interacting exchange factor-binding region, are not required for dimerization. Evidence is presented for the existence of endogenous oligomeric complexes. The implication of dimerization/oligomerization in the functioning of these proteins is discussed.

scholarly journals Does it take two to tango? RING domain self-association and activity in TRIM E3 ubiquitin ligases

2020 ◽  
Vol 48 (6) ◽  
pp. 2615-2624
Author(s):  
Filippo Fiorentini ◽  
Diego Esposito ◽  
Katrin Rittinger
Keyword(s):  
Coiled Coil ◽  
E3 Ligase ◽  
Protein Family ◽  
Ring Domain ◽  
Cellular Functions ◽  
Protein Activity ◽  
Coiled Coil Region ◽  
Tripartite Motif ◽  
Large Protein Family ◽  
Self Association

TRIM proteins form a protein family that is characterized by a conserved tripartite motif domain comprising a RING domain, one or two B-box domains and a coiled-coil region. Members of this large protein family are important regulators of numerous cellular functions including innate immune responses, transcriptional regulation and apoptosis. Key to their cellular role is their E3 ligase activity which is conferred by the RING domain. Self-association is an important characteristic of TRIM protein activity and is mediated by homodimerization via the coiled-coil region, and in some cases higher order association via additional domains of the tripartite motif. In many of the TRIM family proteins studied thus far, RING dimerization is an important prerequisite for E3 ligase enzymatic activity though the propensity of RING domains to dimerize differs significantly between different TRIMs and can be influenced by other regions of the protein.

scholarly journals Complexity of CNC Transcription Factors As Revealed by Gene Targeting of the Nrf3 Locus

2004 ◽  
Vol 24 (8) ◽  
pp. 3286-3294 ◽  
Author(s):  
Anna Derjuga ◽  
Tania S. Gourley ◽  
Teresa M. Holm ◽  
Henry H. Q. Heng ◽  
Ramesh A. Shivdasani ◽  
...  
Keyword(s):  
Transcription Factors ◽  
Leucine Zipper ◽  
B Lymphocyte ◽  
Gross Anatomy ◽  
Related Factor ◽  
Wild Type ◽  
Basic Leucine Zipper ◽  
Mild Phenotype ◽  
Age Progression

ABSTRACT Cap'n'collar (CNC) family basic leucine zipper transcription factors play crucial roles in the regulation of mammalian gene expression and development. To determine the in vivo function of the CNC protein Nrf3 (NF-E2-related factor 3), we generated mice deficient in this transcription factor. We performed targeted disruption of two Nrf3 exons coding for CNC homology, basic DNA-binding, and leucine zipper dimerization domains. Nrf3 null mice developed normally and revealed no obvious phenotypic differences compared to wild-type animals. Nrf3 −/− mice were fertile, and gross anatomy as well as behavior appeared normal. The mice showed normal age progression and did not show any apparent additional phenotype during their life span. We observed no differences in various blood parameters and chemistry values. We infected wild-type and Nrf3 −/− mice with acute lymphocytic choriomeningitis virus and found no differences in these animals with respect to their number of virus-specific CD8 and CD4 T cells as well as their B-lymphocyte response. To determine whether the mild phenotype of Nrf3 null animals is due to functional redundancy, we generated mice deficient in multiple CNC factors. Contrary to our expectations, an absence of Nrf3 does not seem to cause additional lethality in compound Nrf3 −/−/Nrf2 −/− and Nrf3 −/−/p45 −/− mice. We hypothesize that the role of Nrf3 in vivo may become apparent only after appropriate challenge to the mice.

scholarly journals NEMO oligomerization and its ubiquitin-binding properties

2009 ◽  
Vol 421 (2) ◽  
pp. 243-251 ◽  
Author(s):  
Frank J. Ivins ◽  
Mark G. Montgomery ◽  
Susan J. M. Smith ◽  
Aylin C. Morris-Davies ◽  
Ian A. Taylor ◽  
...  
Keyword(s):  
Leucine Zipper ◽  
Target Genes ◽  
Nuclear Translocation ◽  
Coiled Coil ◽  
Nuclear Factor Κb ◽  
Regulatory Subunit ◽  
Activation Process ◽  
Oligomeric State ◽  
Coiled Coil Region ◽  
Ikk Complex

The IKK [IκB (inhibitory κB) kinase] complex is a key regulatory component of NF-κB (nuclear factor κB) activation and is responsible for mediating the degradation of IκB, thereby allowing nuclear translocation of NF-κB and transcription of target genes. NEMO (NF-κB essential modulator), the regulatory subunit of the IKK complex, plays a pivotal role in this process by integrating upstream signals, in particular the recognition of polyubiquitin chains, and relaying these to the activation of IKKα and IKKβ, the catalytic subunits of the IKK complex. The oligomeric state of NEMO is controversial and the mechanism by which it regulates activation of the IKK complex is poorly understood. Using a combination of hydrodynamic techniques we now show that apo-NEMO is a highly elongated, dimeric protein that is in weak equilibrium with a tetrameric assembly. Interaction with peptides derived from IKKβ disrupts formation of the tetrameric NEMO complex, indicating that interaction with IKKα and IKKβ and tetramerization are mutually exclusive. Furthermore, we show that NEMO binds to linear di-ubiquitin with a stoichiometry of one molecule of di-ubiquitin per NEMO dimer. This stoichiometry is preserved in a construct comprising the second coiled-coil region and the leucine zipper and in one that essentially spans the full-length protein. However, our data show that at high di-ubiquitin concentrations a second weaker binding site becomes apparent, implying that two different NEMO–di-ubiquitin complexes are formed during the IKK activation process. We propose that the role of these two complexes is to provide a threshold for activation, thereby ensuring sufficient specificity during NF-κB signalling.

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