Browsing by Subject "Ubiquitin-Protein Ligases"

Now showing 1 - 8 of 8

Open Access
A network of substrates of the E3 ubiquitin ligases MDM2 and HUWE1 control apoptosis independently of p53.
(Sci Signal, 2013-05-07) Kurokawa, Manabu; Kim, Jiyeon; Geradts, Joseph; Matsuura, Kenkyo; Liu, Liu; Ran, Xu; Xia, Wenle; Ribar, Thomas J; Henao, Ricardo; Dewhirst, Mark W; Kim, Wun-Jae; Lucas, Joseph E; Wang, Shaomeng; Spector, Neil L; Kornbluth, Sally
In the intrinsic pathway of apoptosis, cell-damaging signals promote the release of cytochrome c from mitochondria, triggering activation of the Apaf-1 and caspase-9 apoptosome. The ubiquitin E3 ligase MDM2 decreases the stability of the proapoptotic factor p53. We show that it also coordinated apoptotic events in a p53-independent manner by ubiquitylating the apoptosome activator CAS and the ubiquitin E3 ligase HUWE1. HUWE1 ubiquitylates the antiapoptotic factor Mcl-1, and we found that HUWE1 also ubiquitylated PP5 (protein phosphatase 5), which indirectly inhibited apoptosome activation. Breast cancers that are positive for the tyrosine receptor kinase HER2 (human epidermal growth factor receptor 2) tend to be highly aggressive. In HER2-positive breast cancer cells treated with the HER2 tyrosine kinase inhibitor lapatinib, MDM2 was degraded and HUWE1 was stabilized. In contrast, in breast cancer cells that acquired resistance to lapatinib, the abundance of MDM2 was not decreased and HUWE1 was degraded, which inhibited apoptosis, regardless of p53 status. MDM2 inhibition overcame lapatinib resistance in cells with either wild-type or mutant p53 and in xenograft models. These findings demonstrate broader, p53-independent roles for MDM2 and HUWE1 in apoptosis and specifically suggest the potential for therapy directed against MDM2 to overcome lapatinib resistance.
Open Access
ABL kinases regulate the stabilization of HIF-1α and MYC through CPSF1.
(Proceedings of the National Academy of Sciences of the United States of America, 2023-04) Mayro, Benjamin; Hoj, Jacob P; Cerda-Smith, Christian G; Hutchinson, Haley M; Caminear, Michael W; Thrash, Hannah L; Winter, Peter S; Wardell, Suzanne E; McDonnell, Donald P; Wu, Colleen; Wood, Kris C; Pendergast, Ann Marie
The hypoxia-inducible factor 1-α (HIF-1α) enables cells to adapt and respond to hypoxia (Hx), and the activity of this transcription factor is regulated by several oncogenic signals and cellular stressors. While the pathways controlling normoxic degradation of HIF-1α are well understood, the mechanisms supporting the sustained stabilization and activity of HIF-1α under Hx are less clear. We report that ABL kinase activity protects HIF-1α from proteasomal degradation during Hx. Using a fluorescence-activated cell sorting (FACS)-based CRISPR/Cas9 screen, we identified HIF-1α as a substrate of the cleavage and polyadenylation specificity factor-1 (CPSF1), an E3-ligase which targets HIF-1α for degradation in the presence of an ABL kinase inhibitor in Hx. We show that ABL kinases phosphorylate and interact with CUL4A, a cullin ring ligase adaptor, and compete with CPSF1 for CUL4A binding, leading to increased HIF-1α protein levels. Further, we identified the MYC proto-oncogene protein as a second CPSF1 substrate and show that active ABL kinase protects MYC from CPSF1-mediated degradation. These studies uncover a role for CPSF1 in cancer pathobiology as an E3-ligase antagonizing the expression of the oncogenic transcription factors, HIF-1α and MYC.
Open Access
Altered ultrasonic vocalization and impaired learning and memory in Angelman syndrome mouse model with a large maternal deletion from Ube3a to Gabrb3.
(PLoS One, 2010-08-20) Jiang, Yong-Hui; Pan, Yanzhen; Zhu, Li; Landa, Luis; Yoo, Jong; Spencer, Corinne; Lorenzo, Isabel; Brilliant, Murray; Noebels, Jeffrey; Beaudet, Arthur L
Angelman syndrome (AS) is a neurobehavioral disorder associated with mental retardation, absence of language development, characteristic electroencephalography (EEG) abnormalities and epilepsy, happy disposition, movement or balance disorders, and autistic behaviors. The molecular defects underlying AS are heterogeneous, including large maternal deletions of chromosome 15q11-q13 (70%), paternal uniparental disomy (UPD) of chromosome 15 (5%), imprinting mutations (rare), and mutations in the E6-AP ubiquitin ligase gene UBE3A (15%). Although patients with UBE3A mutations have a wide spectrum of neurological phenotypes, their features are usually milder than AS patients with deletions of 15q11-q13. Using a chromosomal engineering strategy, we generated mutant mice with a 1.6-Mb chromosomal deletion from Ube3a to Gabrb3, which inactivated the Ube3a and Gabrb3 genes and deleted the Atp10a gene. Homozygous deletion mutant mice died in the perinatal period due to a cleft palate resulting from the null mutation in Gabrb3 gene. Mice with a maternal deletion (m-/p+) were viable and did not have any obvious developmental defects. Expression analysis of the maternal and paternal deletion mice confirmed that the Ube3a gene is maternally expressed in brain, and showed that the Atp10a and Gabrb3 genes are biallelically expressed in all brain sub-regions studied. Maternal (m-/p+), but not paternal (m+/p-), deletion mice had increased spontaneous seizure activity and abnormal EEG. Extensive behavioral analyses revealed significant impairment in motor function, learning and memory tasks, and anxiety-related measures assayed in the light-dark box in maternal deletion but not paternal deletion mice. Ultrasonic vocalization (USV) recording in newborns revealed that maternal deletion pups emitted significantly more USVs than wild-type littermates. The increased USV in maternal deletion mice suggests abnormal signaling behavior between mothers and pups that may reflect abnormal communication behaviors in human AS patients. Thus, mutant mice with a maternal deletion from Ube3a to Gabrb3 provide an AS mouse model that is molecularly more similar to the contiguous gene deletion form of AS in humans than mice with Ube3a mutation alone. These mice will be valuable for future comparative studies to mice with maternal deficiency of Ube3a alone.
Open Access
Genome-wide analyses of exonic copy number variants in a family-based study point to novel autism susceptibility genes.
(PLoS Genet, 2009-06) Bucan, Maja; Abrahams, Brett S; Wang, Kai; Glessner, Joseph T; Herman, Edward I; Sonnenblick, Lisa I; Alvarez Retuerto, Ana I; Imielinski, Marcin; Hadley, Dexter; Bradfield, Jonathan P; Kim, Cecilia; Gidaya, Nicole B; Lindquist, Ingrid; Hutman, Ted; Sigman, Marian; Kustanovich, Vlad; Lajonchere, Clara M; Singleton, Andrew; Kim, Junhyong; Wassink, Thomas H; McMahon, William M; Owley, Thomas; Sweeney, John A; Coon, Hilary; Nurnberger, John I; Li, Mingyao; Cantor, Rita M; Minshew, Nancy J; Sutcliffe, James S; Cook, Edwin H; Dawson, Geraldine; Buxbaum, Joseph D; Grant, Struan FA; Schellenberg, Gerard D; Geschwind, Daniel H; Hakonarson, Hakon
The genetics underlying the autism spectrum disorders (ASDs) is complex and remains poorly understood. Previous work has demonstrated an important role for structural variation in a subset of cases, but has lacked the resolution necessary to move beyond detection of large regions of potential interest to identification of individual genes. To pinpoint genes likely to contribute to ASD etiology, we performed high density genotyping in 912 multiplex families from the Autism Genetics Resource Exchange (AGRE) collection and contrasted results to those obtained for 1,488 healthy controls. Through prioritization of exonic deletions (eDels), exonic duplications (eDups), and whole gene duplication events (gDups), we identified more than 150 loci harboring rare variants in multiple unrelated probands, but no controls. Importantly, 27 of these were confirmed on examination of an independent replication cohort comprised of 859 cases and an additional 1,051 controls. Rare variants at known loci, including exonic deletions at NRXN1 and whole gene duplications encompassing UBE3A and several other genes in the 15q11-q13 region, were observed in the course of these analyses. Strong support was likewise observed for previously unreported genes such as BZRAP1, an adaptor molecule known to regulate synaptic transmission, with eDels or eDups observed in twelve unrelated cases but no controls (p = 2.3x10(-5)). Less is known about MDGA2, likewise observed to be case-specific (p = 1.3x10(-4)). But, it is notable that the encoded protein shows an unexpectedly high similarity to Contactin 4 (BLAST E-value = 3x10(-39)), which has also been linked to disease. That hundreds of distinct rare variants were each seen only once further highlights complexity in the ASDs and points to the continued need for larger cohorts.
Open Access
International meta-analysis of PTSD genome-wide association studies identifies sex- and ancestry-specific genetic risk loci.
(Nature communications, 2019-10) Nievergelt, Caroline M; Maihofer, Adam X; Klengel, Torsten; Atkinson, Elizabeth G; Chen, Chia-Yen; Choi, Karmel W; Coleman, Jonathan RI; Dalvie, Shareefa; Duncan, Laramie E; Gelernter, Joel; Levey, Daniel F; Logue, Mark W; Polimanti, Renato; Provost, Allison C; Ratanatharathorn, Andrew; Stein, Murray B; Torres, Katy; Aiello, Allison E; Almli, Lynn M; Amstadter, Ananda B; Andersen, Søren B; Andreassen, Ole A; Arbisi, Paul A; Ashley-Koch, Allison E; Austin, S Bryn; Avdibegovic, Esmina; Babić, Dragan; Bækvad-Hansen, Marie; Baker, Dewleen G; Beckham, Jean C; Bierut, Laura J; Bisson, Jonathan I; Boks, Marco P; Bolger, Elizabeth A; Børglum, Anders D; Bradley, Bekh; Brashear, Megan; Breen, Gerome; Bryant, Richard A; Bustamante, Angela C; Bybjerg-Grauholm, Jonas; Calabrese, Joseph R; Caldas-de-Almeida, José M; Dale, Anders M; Daly, Mark J; Daskalakis, Nikolaos P; Deckert, Jürgen; Delahanty, Douglas L; Dennis, Michelle F; Disner, Seth G; Domschke, Katharina; Dzubur-Kulenovic, Alma; Erbes, Christopher R; Evans, Alexandra; Farrer, Lindsay A; Feeny, Norah C; Flory, Janine D; Forbes, David; Franz, Carol E; Galea, Sandro; Garrett, Melanie E; Gelaye, Bizu; Geuze, Elbert; Gillespie, Charles; Uka, Aferdita Goci; Gordon, Scott D; Guffanti, Guia; Hammamieh, Rasha; Harnal, Supriya; Hauser, Michael A; Heath, Andrew C; Hemmings, Sian MJ; Hougaard, David Michael; Jakovljevic, Miro; Jett, Marti; Johnson, Eric Otto; Jones, Ian; Jovanovic, Tanja; Qin, Xue-Jun; Junglen, Angela G; Karstoft, Karen-Inge; Kaufman, Milissa L; Kessler, Ronald C; Khan, Alaptagin; Kimbrel, Nathan A; King, Anthony P; Koen, Nastassja; Kranzler, Henry R; Kremen, William S; Lawford, Bruce R; Lebois, Lauren AM; Lewis, Catrin E; Linnstaedt, Sarah D; Lori, Adriana; Lugonja, Bozo; Luykx, Jurjen J; Lyons, Michael J; Maples-Keller, Jessica; Marmar, Charles; Martin, Alicia R; Martin, Nicholas G; Maurer, Douglas; Mavissakalian, Matig R; McFarlane, Alexander; McGlinchey, Regina E; McLaughlin, Katie A; McLean, Samuel A; McLeay, Sarah; Mehta, Divya; Milberg, William P; Miller, Mark W; Morey, Rajendra A; Morris, Charles Phillip; Mors, Ole; Mortensen, Preben B; Neale, Benjamin M; Nelson, Elliot C; Nordentoft, Merete; Norman, Sonya B; O'Donnell, Meaghan; Orcutt, Holly K; Panizzon, Matthew S; Peters, Edward S; Peterson, Alan L; Peverill, Matthew; Pietrzak, Robert H; Polusny, Melissa A; Rice, John P; Ripke, Stephan; Risbrough, Victoria B; Roberts, Andrea L; Rothbaum, Alex O; Rothbaum, Barbara O; Roy-Byrne, Peter; Ruggiero, Ken; Rung, Ariane; Rutten, Bart PF; Saccone, Nancy L; Sanchez, Sixto E; Schijven, Dick; Seedat, Soraya; Seligowski, Antonia V; Seng, Julia S; Sheerin, Christina M; Silove, Derrick; Smith, Alicia K; Smoller, Jordan W; Sponheim, Scott R; Stein, Dan J; Stevens, Jennifer S; Sumner, Jennifer A; Teicher, Martin H; Thompson, Wesley K; Trapido, Edward; Uddin, Monica; Ursano, Robert J; van den Heuvel, Leigh Luella; Van Hooff, Miranda; Vermetten, Eric; Vinkers, Christiaan H; Voisey, Joanne; Wang, Yunpeng; Wang, Zhewu; Werge, Thomas; Williams, Michelle A; Williamson, Douglas E; Winternitz, Sherry; Wolf, Christiane; Wolf, Erika J; Wolff, Jonathan D; Yehuda, Rachel; Young, Ross McD; Young, Keith A; Zhao, Hongyu; Zoellner, Lori A; Liberzon, Israel; Ressler, Kerry J; Haas, Magali; Koenen, Karestan C
The risk of posttraumatic stress disorder (PTSD) following trauma is heritable, but robust common variants have yet to be identified. In a multi-ethnic cohort including over 30,000 PTSD cases and 170,000 controls we conduct a genome-wide association study of PTSD. We demonstrate SNP-based heritability estimates of 5-20%, varying by sex. Three genome-wide significant loci are identified, 2 in European and 1 in African-ancestry analyses. Analyses stratified by sex implicate 3 additional loci in men. Along with other novel genes and non-coding RNAs, a Parkinson's disease gene involved in dopamine regulation, PARK2, is associated with PTSD. Finally, we demonstrate that polygenic risk for PTSD is significantly predictive of re-experiencing symptoms in the Million Veteran Program dataset, although specific loci did not replicate. These results demonstrate the role of genetic variation in the biology of risk for PTSD and highlight the necessity of conducting sex-stratified analyses and expanding GWAS beyond European ancestry populations.
Open Access
Reactivation of PTEN tumor suppressor for cancer treatment through inhibition of a MYC-WWP1 inhibitory pathway.
(Science (New York, N.Y.), 2019-05) Lee, Yu-Ru; Chen, Ming; Lee, Jonathan D; Zhang, Jinfang; Lin, Shu-Yu; Fu, Tian-Min; Chen, Hao; Ishikawa, Tomoki; Chiang, Shang-Yin; Katon, Jesse; Zhang, Yang; Shulga, Yulia V; Bester, Assaf C; Fung, Jacqueline; Monteleone, Emanuele; Wan, Lixin; Shen, Chen; Hsu, Chih-Hung; Papa, Antonella; Clohessy, John G; Teruya-Feldstein, Julie; Jain, Suresh; Wu, Hao; Matesic, Lydia; Chen, Ruey-Hwa; Wei, Wenyi; Pandolfi, Pier Paolo
Activation of tumor suppressors for the treatment of human cancer has been a long sought, yet elusive, strategy. PTEN is a critical tumor suppressive phosphatase that is active in its dimer configuration at the plasma membrane. Polyubiquitination by the ubiquitin E3 ligase WWP1 (WW domain-containing ubiquitin E3 ligase 1) suppressed the dimerization, membrane recruitment, and function of PTEN. Either genetic ablation or pharmacological inhibition of WWP1 triggered PTEN reactivation and unleashed tumor suppressive activity. WWP1 appears to be a direct MYC (MYC proto-oncogene) target gene and was critical for MYC-driven tumorigenesis. We identified indole-3-carbinol, a compound found in cruciferous vegetables, as a natural and potent WWP1 inhibitor. Thus, our findings unravel a potential therapeutic strategy for cancer prevention and treatment through PTEN reactivation.
Open Access
The APC/C E3 Ligase Complex Activator FZR1 Restricts BRAF Oncogenic Function.
(Cancer discovery, 2017-04) Wan, Lixin; Chen, Ming; Cao, Juxiang; Dai, Xiangpeng; Yin, Qing; Zhang, Jinfang; Song, Su-Jung; Lu, Ying; Liu, Jing; Inuzuka, Hiroyuki; Katon, Jesse M; Berry, Kelsey; Fung, Jacqueline; Ng, Christopher; Liu, Pengda; Song, Min Sup; Xue, Lian; Bronson, Roderick T; Kirschner, Marc W; Cui, Rutao; Pandolfi, Pier Paolo; Wei, Wenyi
BRAF drives tumorigenesis by coordinating the activation of the RAS/RAF/MEK/ERK oncogenic signaling cascade. However, upstream pathways governing BRAF kinase activity and protein stability remain undefined. Here, we report that in primary cells with active APCFZR1, APCFZR1 earmarks BRAF for ubiquitination-mediated proteolysis, whereas in cancer cells with APC-free FZR1, FZR1 suppresses BRAF through disrupting BRAF dimerization. Moreover, we identified FZR1 as a direct target of ERK and CYCLIN D1/CDK4 kinases. Phosphorylation of FZR1 inhibits APCFZR1, leading to elevation of a cohort of oncogenic APCFZR1 substrates to facilitate melanomagenesis. Importantly, CDK4 and/or BRAF/MEK inhibitors restore APCFZR1 E3 ligase activity, which might be critical for their clinical effects. Furthermore, FZR1 depletion cooperates with AKT hyperactivation to transform primary melanocytes, whereas genetic ablation of Fzr1 synergizes with Pten loss, leading to aberrant coactivation of BRAF/ERK and AKT signaling in mice. Our findings therefore reveal a reciprocal suppression mechanism between FZR1 and BRAF in controlling tumorigenesis.Significance: FZR1 inhibits BRAF oncogenic functions via both APC-dependent proteolysis and APC-independent disruption of BRAF dimers, whereas hyperactivated ERK and CDK4 reciprocally suppress APCFZR1 E3 ligase activity. Aberrancies in this newly defined signaling network might account for BRAF hyperactivation in human cancers, suggesting that targeting CYCLIN D1/CDK4, alone or in combination with BRAF/MEK inhibition, can be an effective anti-melanoma therapy. Cancer Discov; 7(4); 424-41. ©2017 AACR.See related commentary by Zhang and Bollag, p. 356This article is highlighted in the In This Issue feature, p. 339.
Open Access
The kinase Grk2 regulates Nedd4/Nedd4-2-dependent control of epithelial Na+ channels.
(Proc Natl Acad Sci U S A, 2004-08-10) Dinudom, Anuwat; Fotia, Andrew B; Lefkowitz, Robert J; Young, John A; Kumar, Sharad; Cook, David I
Epithelial Na(+) channels mediate the transport of Na across epithelia in the kidney, gut, and lungs and are required for blood pressure regulation. They are inhibited by ubiquitin protein ligases, such as Nedd4 and Nedd4-2, with loss of this inhibition leading to hypertension. Here, we report that these channels are maintained in the active state by the G protein-coupled receptor kinase, Grk2, which has been previously implicated in the development of essential hypertension. We also show that Grk2 phosphorylates the C terminus of the channel beta subunit and renders the channels insensitive to inhibition by Nedd4-2. This mechanism has not been previously reported to regulate epithelial Na(+) channels and provides a potential explanation for the observed association of Grk2 overactivity with hypertension. Here, we report a G protein-coupled receptor kinase regulating a membrane protein other than a receptor and provide a paradigm for understanding how the interaction between membrane proteins and ubiquitin protein ligases is controlled.