WW domain-containing E3 ubiquitin protein ligase 1 targets p63 transcription factor for ubiquitin-mediated proteasomal degradation and regulates apoptosis

Ubiquitin-protein ligases (E3s) that ubiquitinate substrates for proteasomal degradation are often in the position of ubiquitinating themselves due to interactions with a charged ubiquitin-conjugating enzyme (E2). This can mediate the E3’s proteasomal degradation. Many E3s have evolved means to avoid autoubiquitination, including protection by partner or substrate binding, preventative modifications, and deubiquitinating enzyme reversal of ubiquitination. Here we describe another adaptation for E3 self-protection discovered while exploring San1, which ubiquitinates misfolded nuclear proteins in yeast for proteasomal degradation. San1 is highly disordered in its substrate-binding regions N- and C-terminal to its RING domain. In cis autoubiquitination could occur if these flexible regions come in proximity to the E2. San1 prevents this by containing no lysines in its disordered regions; thus the canonical residue used for ubiquitin attachment has been selectively eliminated. San1’s target substrates have lost their native structures and expose hydrophobicity. To avoid in trans autoubiquitination, San1 possesses little concentrated hydrophobicity in its disordered regions, and thus the that feature San1 recognizes in misfolded substrates has also been selectively eliminated. Overall the presence of key residues in San1 have been evolutionarily minimized to avoid self-destruction either in cis or in trans. Our work expands the ways in which E3s protect themselves from autoubiquitination.

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Zfhx3 Transcription Factor Represses the Expression of SCN5A Gene and Decreases Sodium Current Density (INa)

International Journal of Molecular Sciences ◽

10.3390/ijms222313031 ◽

2021 ◽

Vol 22 (23) ◽

pp. 13031

Author(s):

Marcos Rubio-Alarcón ◽

Anabel Cámara-Checa ◽

María Dago ◽

Teresa Crespo-García ◽

Paloma Nieto-Marín ◽

...

Keyword(s):

Transcription Factor ◽

Cardiac Tissue ◽

Sodium Current ◽

Na Channel ◽

Ubiquitin Protein Ligase ◽

Endogenous Expression ◽

Voltage Dependent ◽

Familial Atrial Fibrillation ◽

Cardiac Excitability ◽

Scn5a Gene

The ZFHX3 and SCN5A genes encode the zinc finger homeobox 3 (Zfhx3) transcription factor (TF) and the human cardiac Na+ channel (Nav1.5), respectively. The effects of Zfhx3 on the expression of the Nav1.5 channel, and in cardiac excitability, are currently unknown. Additionally, we identified three Zfhx3 variants in probands diagnosed with familial atrial fibrillation (p.M1260T) and Brugada Syndrome (p.V949I and p.Q2564R). Here, we analyzed the effects of native (WT) and mutated Zfhx3 on Na+ current (INa) recorded in HL-1 cardiomyocytes. ZFHX3 mRNA can be detected in human atrial and ventricular samples. In HL-1 cardiomyocytes, transfection of Zfhx3 strongly reduced peak INa density, while the silencing of endogenous expression augmented it (from −65.9 ± 8.9 to −104.6 ± 10.8 pA/pF; n ≥ 8, p < 0.05). Zfhx3 significantly reduced the transcriptional activity of human SCN5A, PITX2, TBX5, and NKX25 minimal promoters. Consequently, the mRNA and/or protein expression levels of Nav1.5 and Tbx5 were diminished (n ≥ 6, p < 0.05). Zfhx3 also increased the expression of Nedd4-2 ubiquitin-protein ligase, enhancing Nav1.5 proteasomal degradation. p.V949I, p.M1260T, and p.Q2564R Zfhx3 produced similar effects on INa density and time- and voltage-dependent properties in WT. WT Zfhx3 inhibits INa as a result of a direct repressor effect on the SCN5A promoter, the modulation of Tbx5 increasing on the INa, and the increased expression of Nedd4-2. We propose that this TF participates in the control of cardiac excitability in human adult cardiac tissue.

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A WW domain protein TAZ is a critical coactivator for TBX5, a transcription factor implicated in Holt-Oram syndrome

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.0509109102 ◽

2005 ◽

Vol 102 (50) ◽

pp. 18034-18039 ◽

Cited By ~ 178

Author(s):

M. Murakami ◽

M. Nakagawa ◽

E. N. Olson ◽

O. Nakagawa

Keyword(s):

Transcription Factor ◽

Ww Domain ◽

Domain Protein

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Dual regulation of transcription factor Nrf2 by Keap1 and by the combined actions of β-TrCP and GSK-3

Biochemical Society Transactions ◽

10.1042/bst20150011 ◽

2015 ◽

Vol 43 (4) ◽

pp. 611-620 ◽

Cited By ~ 59

Author(s):

John D. Hayes ◽

Sudhir Chowdhry ◽

Albena T. Dinkova-Kostova ◽

Calum Sutherland

Keyword(s):

Transcription Factor ◽

Growth Factors ◽

Ubiquitin Ligase ◽

Molecular Mechanisms ◽

Glycogen Synthase ◽

Proteasomal Degradation ◽

Regulation Of Transcription ◽

Related Factor ◽

Nrf2 Target Gene ◽

The Stability

Nuclear factor-erythroid 2 p45 (NF-E2 p45)-related factor 2 (Nrf2) is a master regulator of redox homoeostasis that allows cells to adapt to oxidative stress and also promotes cell proliferation. In this review, we describe the molecular mechanisms by which oxidants/electrophilic agents and growth factors increase Nrf2 activity. In the former case, oxidants/electrophiles increase the stability of Nrf2 by antagonizing the ability of Kelch-like ECH-associated protein 1 (Keap1) to target the transcription factor for proteasomal degradation via the cullin-3 (Cul3)–RING ubiquitin ligase CRLKeap1. In the latter case, we speculate that growth factors increase the stability of Nrf2 by stimulating phosphoinositide 3-kinase (PI3K)−protein kinase B (PKB)/Akt signalling, which in turn results in inhibitory phosphorylation of glycogen synthase kinase-3 (GSK-3) and in doing so prevents the formation of a DSGIS motif-containing phosphodegron in Nrf2 that is recognized by the β-transducin repeat-containing protein (β-TrCP) Cul1-based E3 ubiquitin ligase complex SCFβ-TrCP. We present data showing that in the absence of Keap1, the electrophile tert-butyl hydroquinone (tBHQ) can stimulate Nrf2 activity and induce the Nrf2-target gene NAD(P)H:quinone oxidoreductase-1 (NQO1), whilst simultaneously causing inhibitory phosphorylation of GSK-3β at Ser9. Together, these observations suggest that tBHQ can suppress the ability of SCFβ-TrCP to target Nrf2 for proteasomal degradation by increasing PI3K−PKB/Akt signalling. We also propose a scheme that explains how other protein kinases that inhibit GSK-3 could stimulate induction of Nrf2-target genes by preventing formation of the DSGIS motif-containing phosphodegron in Nrf2.

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UFBP1, a key component in ufmylation, enhances drug sensitivity by promoting proteasomal degradation of oxidative stress-response transcription factor Nrf2

Oncogene ◽

10.1038/s41388-020-01551-1 ◽

2020 ◽

Author(s):

Zhanhong Hu ◽

Xiaohui Wang ◽

Dan Li ◽

Lindong Cao ◽

Hongxia Cui ◽

...

Keyword(s):

Oxidative Stress ◽

Transcription Factor ◽

Stress Response ◽

Drug Sensitivity ◽

Proteasomal Degradation ◽

Oxidative Stress Response

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A single WW domain is the predominant mediator of the interaction between the human ubiquitin-protein ligase Nedd4 and the human epithelial sodium channel

Biochemical Journal ◽

10.1042/bj3610481 ◽

2002 ◽

Vol 361 (3) ◽

pp. 481-488 ◽

Cited By ~ 19

Author(s):

J. Shaun LOTT ◽

Sarah J. CODDINGTON-LAWSON ◽

Paul H. TEESDALE-SPITTLE ◽

Fiona J. MCDONALD

Keyword(s):

The Body ◽

Single Amino Acid ◽

Na Channel ◽

Α Subunit ◽

Ww Domain ◽

Ww Domains ◽

Ubiquitin Protein Ligase ◽

Single Amino Acid Change ◽

Domain 3 ◽

Neuronal Precursor Cell

The activity of the epithelial Na+ channel (ENaC) is required for the maintenance of salt and water balance in the body. Channel activity is regulated by the ubiquitin-protein ligase Nedd4 ['neuronal precursor cell-expressed developmentally down-regulated (gene 4)'] that interacts with the channel via its WW domains. Mutations in channel subunits that disrupt this interaction cause Liddle's syndrome, a severe inherited form of hypertension. In previous studies we showed that WW domains 2, 3 and 4 of human Nedd4 bound to the human ENaC (hENaC) subunits, whereas WW domain 1 did not. Here we extend this observation to determine the binding affinities of the human Nedd4 WW domains for hENaC C-terminal peptides. We show that WW domains 2, 3 and 4 bind with differing affinities to Na+ channel subunit peptides. WW domain 3 has the highest affinity and we predict that WW domain 3 contributes most of the binding because a construct containing the three WW domains bound no better than WW domain 3 alone. Further, a single amino acid change (Arg165 → Thr) in WW domain 1 enables binding to the α subunit of the channel to occur, with an affinity comparable with that of WW domain 4. Differential binding propensities between the various WW domains and Na+ channel subunit peptides are explained on the basis of quantitative structural modelling of the complexes and their isolated components.

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