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Corda PO, Bollen M, Ribeiro D, Fardilha M. Emerging roles of the Protein Phosphatase 1 (PP1) in the context of viral infections. Cell Commun Signal 2024; 22:65. [PMID: 38267954 PMCID: PMC10807198 DOI: 10.1186/s12964-023-01468-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2023] [Accepted: 12/30/2023] [Indexed: 01/26/2024] Open
Abstract
Protein Phosphatase 1 (PP1) is a major serine/threonine phosphatase in eukaryotes, participating in several cellular processes and metabolic pathways. Due to their low substrate specificity, PP1's catalytic subunits do not exist as free entities but instead bind to Regulatory Interactors of Protein Phosphatase One (RIPPO), which regulate PP1's substrate specificity and subcellular localization. Most RIPPOs bind to PP1 through combinations of short linear motifs (4-12 residues), forming highly specific PP1 holoenzymes. These PP1-binding motifs may, hence, represent attractive targets for the development of specific drugs that interfere with a subset of PP1 holoenzymes. Several viruses exploit the host cell protein (de)phosphorylation machinery to ensure efficient virus particle formation and propagation. While the role of many host cell kinases in viral life cycles has been extensively studied, the targeting of phosphatases by viral proteins has been studied in less detail. Here, we compile and review what is known concerning the role of PP1 in the context of viral infections and discuss how it may constitute a putative host-based target for the development of novel antiviral strategies.
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Affiliation(s)
- Pedro O Corda
- Institute of Biomedicine (iBiMED), Department of Medical Sciences, University of Aveiro, Aveiro, Portugal
| | - Mathieu Bollen
- Department of Cellular and Molecular Medicine, Laboratory of Biosignaling & Therapeutics, Katholieke Universiteit Leuven, Louvain, Belgium
| | - Daniela Ribeiro
- Institute of Biomedicine (iBiMED), Department of Medical Sciences, University of Aveiro, Aveiro, Portugal.
| | - Margarida Fardilha
- Institute of Biomedicine (iBiMED), Department of Medical Sciences, University of Aveiro, Aveiro, Portugal.
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2
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Mariani NAP, Silva JV, Fardilha M, Silva EJR. Advances in non-hormonal male contraception targeting sperm motility. Hum Reprod Update 2023; 29:545-569. [PMID: 37141450 DOI: 10.1093/humupd/dmad008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2022] [Revised: 03/23/2023] [Indexed: 05/06/2023] Open
Abstract
BACKGROUND The high rates of unintended pregnancy and the ever-growing world population impose health, economic, social, and environmental threats to countries. Expanding contraceptive options, including male methods, are urgently needed to tackle these global challenges. Male contraception is limited to condoms and vasectomy, which are unsuitable for many couples. Thus, novel male contraceptive methods may reduce unintended pregnancies, meet the contraceptive needs of couples, and foster gender equality in carrying the contraceptive burden. In this regard, the spermatozoon emerges as a source of druggable targets for on-demand, non-hormonal male contraception based on disrupting sperm motility or fertilization. OBJECTIVE AND RATIONALE A better understanding of the molecules governing sperm motility can lead to innovative approaches toward safe and effective male contraceptives. This review discusses cutting-edge knowledge on sperm-specific targets for male contraception, focusing on those with crucial roles in sperm motility. We also highlight challenges and opportunities in male contraceptive drug development targeting spermatozoa. SEARCH METHODS We conducted a literature search in the PubMed database using the following keywords: 'spermatozoa', 'sperm motility', 'male contraception', and 'drug targets' in combination with other related terms to the field. Publications until January 2023 written in English were considered. OUTCOMES Efforts for developing non-hormonal strategies for male contraception resulted in the identification of candidates specifically expressed or enriched in spermatozoa, including enzymes (PP1γ2, GAPDHS, and sAC), ion channels (CatSper and KSper), transmembrane transporters (sNHE, SLC26A8, and ATP1A4), and surface proteins (EPPIN). These targets are usually located in the sperm flagellum. Their indispensable roles in sperm motility and male fertility were confirmed by genetic or immunological approaches using animal models and gene mutations associated with male infertility due to sperm defects in humans. Their druggability was demonstrated by the identification of drug-like small organic ligands displaying spermiostatic activity in preclinical trials. WIDER IMPLICATIONS A wide range of sperm-associated proteins has arisen as key regulators of sperm motility, providing compelling druggable candidates for male contraception. Nevertheless, no pharmacological agent has reached clinical developmental stages. One reason is the slow progress in translating the preclinical and drug discovery findings into a drug-like candidate adequate for clinical development. Thus, intense collaboration among academia, private sectors, governments, and regulatory agencies will be crucial to combine expertise for the development of male contraceptives targeting sperm function by (i) improving target structural characterization and the design of highly selective ligands, (ii) conducting long-term preclinical safety, efficacy, and reversibility evaluation, and (iii) establishing rigorous guidelines and endpoints for clinical trials and regulatory evaluation, thus allowing their testing in humans.
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Affiliation(s)
- Noemia A P Mariani
- Department of Biophysics and Pharmacology, Institute of Biosciences of Botucatu, São Paulo State University, Botucatu, Brazil
| | - Joana V Silva
- Department of Medical Sciences, Institute of Biomedicine (iBiMED), University of Aveiro, Aveiro, Portugal
- QOPNA & LAQV, Department of Chemistry, University of Aveiro, Aveiro, Portugal
- Multidisciplinary Research in Biomedicine (UMIB), Institute of Biomedical Sciences Abel Salazar (ICBAS), University of Porto, Porto, Portugal
| | - Margarida Fardilha
- Department of Medical Sciences, Institute of Biomedicine (iBiMED), University of Aveiro, Aveiro, Portugal
| | - Erick J R Silva
- Department of Biophysics and Pharmacology, Institute of Biosciences of Botucatu, São Paulo State University, Botucatu, Brazil
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3
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Ahmad A, Tigabu B, Ivanov A, Jerebtsova M, Ammosova T, Ramanathan P, Kumari N, Brantner CA, Pietzsch CA, Abdullah G, Popratiloff A, Widen S, Bukreyev A, Nekhai S. Ebola Virus NP Binding to Host Protein Phosphatase-1 Regulates Capsid Formation. RESEARCH SQUARE 2023:rs.3.rs-2963943. [PMID: 37333330 PMCID: PMC10274954 DOI: 10.21203/rs.3.rs-2963943/v1] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/20/2023]
Abstract
The Ebola virus (EBOV) transcriptional regulation involves host protein phosphatases PP1 and PP2A, which dephosphorylate the transcriptional cofactor of EBOV polymerase VP30. The 1E7-03 compound, which targets PP1, induces VP30 phosphorylation and inhibits EBOV infection. This study aimed to investigate the role of PP1 in EBOV replication. When EBOV-infected cells were continuously treated with 1E7-03, the NP E619K mutation was selected. This mutation moderately reduced EBOV minigenome transcription, which was restored by the treatment with 1E7-03. Formation of EBOV capsids, when NP was co-expressed with VP24 and VP35, was impaired with NPE 619K. Treatment with 1E7-03 restored capsid formation by NP E619K mutation, but inhibited capsids formed by WT NP. The dimerization of NP E619K, tested in a split NanoBiT assay, was significantly decreased (~ 15-fold) compared to WT NP. NP E619K bound more efficiently to PP1 (~ 3-fold) but not B56 subunit of PP2A or VP30. Cross-linking and co-immunoprecipitation experiments showed fewer monomers and dimers for NP E619K which were increased with 1E7-03 treatment. NP E619K showed increased co-localization with PP1α compared to WT NP. Mutations of potential PP1 binding sites and NP deletions disrupted its interaction with PP1. Collectively, our findings suggest that PP1 binding to the NP regulates NP dimerization and capsid formation, and that NP E619K mutation, which has the enhanced PP1 binding, disrupts these processes. Our results point to a new role for PP1 in EBOV replication in which NP binding to PP1 may facilitate viral transcription by delaying capsid formation and EBOV replication.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | | | | | - Steve Widen
- UTMB: The University of Texas Medical Branch at Galveston
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4
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Lin X, Ahmad A, Ivanov AI, Simhadri J, Wang S, Kumari N, Ammosova T, Nekhai S. HIV-1 Transcription Inhibitor 1E7-03 Decreases Nucleophosmin Phosphorylation. Mol Cell Proteomics 2023; 22:100488. [PMID: 36563749 PMCID: PMC9975258 DOI: 10.1016/j.mcpro.2022.100488] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2022] [Revised: 12/07/2022] [Accepted: 12/18/2022] [Indexed: 12/25/2022] Open
Abstract
Transcription activation of latent human immunodeficiency virus-1 (HIV-1) occurs due to HIV-1 rebound, the interruption of combination antiretroviral therapy, or development of drug resistance. Thus, novel HIV-1 inhibitors, targeting HIV-1 transcription are needed. We previously developed an HIV-1 transcription inhibitor, 1E7-03, that binds to the noncatalytic RVxF-accommodating site of protein phosphatase 1 and inhibits HIV-1 replication in cultured cells and HIV-1-infected humanized mice by impeding protein phosphatase 1 interaction with HIV-1 Tat protein. However, host proteins and regulatory pathways targeted by 1E7-03 that contribute to its overall HIV-1 inhibitory activity remain to be identified. To address this issue, we performed label-free quantitative proteome and phosphoproteome analyses of noninfected and HIV-1-infected CEM T cells that were untreated or treated with 1E7-03. 1E7-03 significantly reprogramed the phosphorylation profile of proteins including PPARα/RXRα, TGF-β, and PKR pathways. Phosphorylation of nucleophosmin (NPM1) at Ser-125 residue in PPARα/RXRα pathway was significantly reduced (>20-fold, p = 1.37 × 10-9), followed by the reduced phosphorylation of transforming growth factor-beta 2 at Ser-46 (TGF-β2, >12-fold, p = 1.37 × 10-3). Downregulation of NPM1's Ser-125 phosphorylation was further confirmed using Western blot. Phosphorylation mimicking NPM1 S125D mutant activated Tat-induced HIV-1 transcription and exhibited enhanced NPM1-Tat interaction compared to NPM1 S125A mutant. Inhibition of Aurora A or Aurora B kinases that phosphorylate NPM1 on Ser-125 residue inhibited HIV-1, further supporting the role of NPM1 in HIV-1 infection. Taken together, 1E7-03 reprogrammed PPARα/RXRα and TGF-β pathways that contribute to the inhibition of HIV-1 transcription. Our findings suggest that NPM1 phosphorylation is a plausible target for HIV-1 transcription inhibition.
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Key Words
- actn4, alpha-actinin-1
- asl, argininosuccinate lyase
- aspm, abnormal spindle-like microcephaly-associated protein
- cart, combination antiretroviral therapy
- cdk2, cell cycle-dependent kinase 2
- ck2, casein kinase 2
- dmso, dimethyl sulfoxide
- egln1, egl-9 family hypoxia inducible factor 1
- erk/p38, extracellular signal-regulated kinase p38
- fa, formic acid
- gadd34, growth arrest and dna damage-inducible protein
- hif-1α, hypoxia-inducible factor 1α
- hiv-1 vif protein, viral infectivity factor, an hiv-1 accessory protein
- hiv-1, human immunodeficiency virus-1
- hsp90, heat shock protein 90
- ipa, ingenuity pathway analysis
- lc-ft/ms, tandem liquid chromatography-fourier transform mass spectrometry
- mapk, mitogen-activated protein kinase
- map3k4, mitogen-activated protein kinase kinase kinase 4
- mita, mediator of interferon response factor 3 activation
- nfat, nuclear factor of activated t cells
- nf-κb, nuclear factor kappa-light-chain-enhancer of activated b cell
- npm1, nucleophosmin
- oa, okadaic acid
- pi3k/akt, phosphoinositide 3-kinase/ ak strain transforming or protein kinase b
- pp, protein phosphatase
- pparα/rxrα, peroxisome proliferator-activated receptor α/ retinoid x receptor α
- ptm, posttranslational modification
- rnr2, ribonucleotide reductase 2
- rt, reverse transcription
- samhd1, sam domain and hd domain-containing protein 1
- smad7, mothers against decapentaplegic homolog 7
- stat5, signal transducer and activator of transcription 5 taf4
- taf4, transcription factor tfiid subunit tata-box-binding protein (tbp)-associated factor 4
- tgf-β2, transforming growth factor-beta
- tp53, tumor protein p53
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Affiliation(s)
- Xionghao Lin
- Center for Sickle Cell Disease, College of Medicine, Howard University, Washington, District of Columbia, USA; College of Dentistry, Howard University, Washington, District of Columbia, USA
| | - Asrar Ahmad
- Center for Sickle Cell Disease, College of Medicine, Howard University, Washington, District of Columbia, USA
| | - Andrey I Ivanov
- Center for Sickle Cell Disease, College of Medicine, Howard University, Washington, District of Columbia, USA
| | - Jyothirmai Simhadri
- Center for Sickle Cell Disease, College of Medicine, Howard University, Washington, District of Columbia, USA
| | - Songping Wang
- Center for Sickle Cell Disease, College of Medicine, Howard University, Washington, District of Columbia, USA
| | - Namita Kumari
- Center for Sickle Cell Disease, College of Medicine, Howard University, Washington, District of Columbia, USA; Department of Microbiology, College of Medicine, Howard University, Washington, District of Columbia, USA
| | - Tatiana Ammosova
- Center for Sickle Cell Disease, College of Medicine, Howard University, Washington, District of Columbia, USA; Department of Medicine, College of Medicine, Howard University, Washington, District of Columbia, USA
| | - Sergei Nekhai
- Center for Sickle Cell Disease, College of Medicine, Howard University, Washington, District of Columbia, USA; Department of Microbiology, College of Medicine, Howard University, Washington, District of Columbia, USA; Department of Medicine, College of Medicine, Howard University, Washington, District of Columbia, USA.
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5
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Ferreira AF, Santiago J, Silva JV, Oliveira PF, Fardilha M. PP1, PP2A and PP2B Interplay in the Regulation of Sperm Motility: Lessons from Protein Phosphatase Inhibitors. Int J Mol Sci 2022; 23:ijms232315235. [PMID: 36499559 PMCID: PMC9737803 DOI: 10.3390/ijms232315235] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2022] [Revised: 11/30/2022] [Accepted: 12/01/2022] [Indexed: 12/11/2022] Open
Abstract
Male fertility relies on the ability of spermatozoa to fertilize the egg in the female reproductive tract (FRT). Spermatozoa acquire activated motility during epididymal maturation; however, to be capable of fertilization, they must achieve hyperactivated motility in the FRT. Extensive research found that three protein phosphatases (PPs) are crucial to sperm motility regulation, the sperm-specific protein phosphatase type 1 (PP1) isoform gamma 2 (PP1γ2), protein phosphatase type 2A (PP2A) and protein phosphatase type 2B (PP2B). Studies have reported that PP activity decreases during epididymal maturation, whereas protein kinase activity increases, which appears to be a requirement for motility acquisition. An interplay between these PPs has been extensively investigated; however, many specific interactions and some inconsistencies remain to be elucidated. The study of PPs significantly advanced following the identification of naturally occurring toxins, including calyculin A, okadaic acid, cyclosporin, endothall and deltamethrin, which are powerful and specific PP inhibitors. This review aims to overview the protein phosphorylation-dependent biochemical pathways underlying sperm motility acquisition and hyperactivation, followed by a discussion of the PP inhibitors that allowed advances in the current knowledge of these pathways. Since male infertility cases still attain alarming numbers, additional research on the topic is required, particularly using other PP inhibitors.
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Affiliation(s)
- Ana F. Ferreira
- Laboratory of Signal Transduction, Institute for Biomedicine-iBiMED, Medical Sciences Department, University of Aveiro, 3810-193 Aveiro, Portugal
| | - Joana Santiago
- Laboratory of Signal Transduction, Institute for Biomedicine-iBiMED, Medical Sciences Department, University of Aveiro, 3810-193 Aveiro, Portugal
| | - Joana V. Silva
- Laboratory of Signal Transduction, Institute for Biomedicine-iBiMED, Medical Sciences Department, University of Aveiro, 3810-193 Aveiro, Portugal
| | - Pedro F. Oliveira
- QOPNA & LAQV, Department of Chemistry, University of Aveiro, 3810-193 Aveiro, Portugal
| | - Margarida Fardilha
- Laboratory of Signal Transduction, Institute for Biomedicine-iBiMED, Medical Sciences Department, University of Aveiro, 3810-193 Aveiro, Portugal
- Correspondence: ; Tel.: +351-918-143-947
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6
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Grillone K, Riillo C, Rocca R, Ascrizzi S, Spanò V, Scionti F, Polerà N, Maruca A, Barreca M, Juli G, Arbitrio M, Di Martino MT, Caracciolo D, Tagliaferri P, Alcaro S, Montalbano A, Barraja P, Tassone P. The New Microtubule-Targeting Agent SIX2G Induces Immunogenic Cell Death in Multiple Myeloma. Int J Mol Sci 2022; 23:ijms231810222. [PMID: 36142133 PMCID: PMC9499408 DOI: 10.3390/ijms231810222] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2022] [Revised: 08/30/2022] [Accepted: 09/01/2022] [Indexed: 12/31/2022] Open
Abstract
Microtubule-targeting agents (MTAs) are effective drugs for cancer treatment. A novel diaryl [1,2]oxazole class of compounds binding the colchicine site was synthesized as cis-restricted-combretastatin-A-4-analogue and then chemically modified to have improved solubility and a wider therapeutic index as compared to vinca alkaloids and taxanes. On these bases, a new class of tricyclic compounds, containing the [1,2]oxazole ring and an isoindole moiety, has been synthetized, among which SIX2G emerged as improved MTA. Several findings highlighted the ability of some chemotherapeutics to induce immunogenic cell death (ICD), which is defined by the cell surface translocation of Calreticulin (CALR) via dissociation of the PP1/GADD34 complex. In this regard, we computationally predicted the ability of SIX2G to induce CALR exposure by interacting with the PP1 RVxF domain. We then assessed both the potential cytotoxic and immunogenic activity of SIX2G on in vitro models of multiple myeloma (MM), which is an incurable hematological malignancy characterized by an immunosuppressive milieu. We found that the treatment with SIX2G inhibited cell viability by inducing G2/M phase cell cycle arrest and apoptosis. Moreover, we observed the increase of hallmarks of ICD such as CALR exposure, ATP release and phospho-eIF2α protein level. Through co-culture experiments with immune cells, we demonstrated the increase of (i) CD86 maturation marker on dendritic cells, (ii) CD69 activation marker on cytotoxic T cells, and (iii) phagocytosis of tumor cells following treatment with SIX2G, confirming the onset of an immunogenic cascade. In conclusion, our findings provide a framework for further development of SIX2G as a new potential anti-MM agent.
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Affiliation(s)
- Katia Grillone
- Department of Experimental and Clinical Medicine, Magna Graecia University of Catanzaro, 88100 Catanzaro, Italy
| | - Caterina Riillo
- Department of Experimental and Clinical Medicine, Magna Graecia University of Catanzaro, 88100 Catanzaro, Italy
| | - Roberta Rocca
- Department of Experimental and Clinical Medicine, Magna Graecia University of Catanzaro, 88100 Catanzaro, Italy
- Net4Science s.r.l., Academic Spinoff, Magna Graecia University of Catanzaro, 88100 Catanzaro, Italy
| | - Serena Ascrizzi
- Department of Experimental and Clinical Medicine, Magna Graecia University of Catanzaro, 88100 Catanzaro, Italy
| | - Virginia Spanò
- Department of Biological, Chemical and Pharmaceutical Sciences and Technologies (STEBICEF), University of Palermo, 90128 Palermo, Italy
| | - Francesca Scionti
- Institute of Research and Biomedical Innovation (IRIB), Italian National Council (CNR), 98122 Messina, Italy
| | - Nicoletta Polerà
- Department of Experimental and Clinical Medicine, Magna Graecia University of Catanzaro, 88100 Catanzaro, Italy
| | - Annalisa Maruca
- Net4Science s.r.l., Academic Spinoff, Magna Graecia University of Catanzaro, 88100 Catanzaro, Italy
| | - Marilia Barreca
- Department of Biological, Chemical and Pharmaceutical Sciences and Technologies (STEBICEF), University of Palermo, 90128 Palermo, Italy
| | - Giada Juli
- Department of Experimental and Clinical Medicine, Magna Graecia University of Catanzaro, 88100 Catanzaro, Italy
| | - Mariamena Arbitrio
- Institute of Research and Biomedical Innovation (IRIB), Italian National Council (CNR), 98122 Messina, Italy
| | - Maria Teresa Di Martino
- Department of Experimental and Clinical Medicine, Magna Graecia University of Catanzaro, 88100 Catanzaro, Italy
| | - Daniele Caracciolo
- Department of Experimental and Clinical Medicine, Magna Graecia University of Catanzaro, 88100 Catanzaro, Italy
| | - Pierosandro Tagliaferri
- Department of Experimental and Clinical Medicine, Magna Graecia University of Catanzaro, 88100 Catanzaro, Italy
| | - Stefano Alcaro
- Net4Science s.r.l., Academic Spinoff, Magna Graecia University of Catanzaro, 88100 Catanzaro, Italy
- Institute of Research and Biomedical Innovation (IRIB), Italian National Council (CNR), 88100 Catanzaro, Italy
| | - Alessandra Montalbano
- Department of Biological, Chemical and Pharmaceutical Sciences and Technologies (STEBICEF), University of Palermo, 90128 Palermo, Italy
- Correspondence: (A.M.); (P.T.); Tel.: +39-0912-389682 (A.M.); +39-0961-364-7029 (P.T.)
| | - Paola Barraja
- Department of Biological, Chemical and Pharmaceutical Sciences and Technologies (STEBICEF), University of Palermo, 90128 Palermo, Italy
| | - Pierfrancesco Tassone
- Department of Experimental and Clinical Medicine, Magna Graecia University of Catanzaro, 88100 Catanzaro, Italy
- Correspondence: (A.M.); (P.T.); Tel.: +39-0912-389682 (A.M.); +39-0961-364-7029 (P.T.)
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7
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Jian Y, Kong L, Xu H, Shi Y, Huang X, Zhong W, Huang S, Li Y, Shi D, Xiao Y, Yang M, Li S, Chen X, Ouyang Y, Hu Y, Chen X, Song L, Ye R, Wei W. Protein phosphatase 1 regulatory inhibitor subunit 14C promotes triple-negative breast cancer progression via sustaining inactive glycogen synthase kinase 3 beta. Clin Transl Med 2022; 12:e725. [PMID: 35090098 PMCID: PMC8797469 DOI: 10.1002/ctm2.725] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2021] [Revised: 12/28/2021] [Accepted: 01/17/2022] [Indexed: 11/21/2022] Open
Abstract
Triple-negative breast cancer (TNBC) is fast-growing and highly metastatic with the poorest prognosis among the breast cancer subtypes. Inactivation of glycogen synthase kinase 3 beta (GSK3β) plays a vital role in the aggressiveness of TNBC; however, the underlying mechanism for sustained GSK3β inhibition remains largely unknown. Here, we find that protein phosphatase 1 regulatory inhibitor subunit 14C (PPP1R14C) is upregulated in TNBC and relevant to poor prognosis in patients. Overexpression of PPP1R14C facilitates cell proliferation and the aggressive phenotype of TNBC cells, whereas the depletion of PPP1R14C elicits opposite effects. Moreover, PPP1R14C is phosphorylated and activated by protein kinase C iota (PRKCI) at Thr73. p-PPP1R14C then represses Ser/Thr protein phosphatase type 1 (PP1) to retain GSK3β phosphorylation at high levels. Furthermore, p-PPP1R14C recruits E3 ligase, TRIM25, toward the ubiquitylation and degradation of non-phosphorylated GSK3β. Importantly, the blockade of PPP1R14C phosphorylation inhibits xenograft tumorigenesis and lung metastasis of TNBC cells. These findings provide a novel mechanism for sustained GSK3β inactivation in TNBC and suggest that PPP1R14C might be a potential therapeutic target.
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Affiliation(s)
- Yunting Jian
- Department of Experimental Research, Sun Yat‐sen University Cancer Center, State Key Laboratory of Oncology in South ChinaCollaborative Innovation Center for Cancer MedicineGuangzhouChina
- Department of Pathology, Key Laboratory of Reproduction and Genetics of Guangdong Higher Education Institutes, Key Laboratory for Major Obstetric Diseases of Guangdong ProvinceThe Third Affiliated Hospital of Guangzhou Medical UniversityGuangzhouChina
| | - Lingzhi Kong
- Department of Experimental Research, Sun Yat‐sen University Cancer Center, State Key Laboratory of Oncology in South ChinaCollaborative Innovation Center for Cancer MedicineGuangzhouChina
| | - Hongyi Xu
- Department of Experimental Research, Sun Yat‐sen University Cancer Center, State Key Laboratory of Oncology in South ChinaCollaborative Innovation Center for Cancer MedicineGuangzhouChina
- Department of Breast SurgerySun Yat‐sen University Cancer CenterGuangzhouChina
| | - Yawei Shi
- Department of Thyroid and Breast SurgeryThe First Affiliated Hospital of Sun Yat‐sen UniversityGuangzhouChina
| | - Xinjian Huang
- Department of Experimental Research, Sun Yat‐sen University Cancer Center, State Key Laboratory of Oncology in South ChinaCollaborative Innovation Center for Cancer MedicineGuangzhouChina
| | - Wenjing Zhong
- Department of Experimental Research, Sun Yat‐sen University Cancer Center, State Key Laboratory of Oncology in South ChinaCollaborative Innovation Center for Cancer MedicineGuangzhouChina
- Department of Breast SurgerySun Yat‐sen University Cancer CenterGuangzhouChina
| | - Shumei Huang
- Department of Biochemistry, Zhongshan School of MedicineSun Yat‐sen UniversityGuangzhouChina
| | - Yue Li
- Department of Experimental Research, Sun Yat‐sen University Cancer Center, State Key Laboratory of Oncology in South ChinaCollaborative Innovation Center for Cancer MedicineGuangzhouChina
| | - Dongni Shi
- Department of Experimental Research, Sun Yat‐sen University Cancer Center, State Key Laboratory of Oncology in South ChinaCollaborative Innovation Center for Cancer MedicineGuangzhouChina
| | - Yunyun Xiao
- Department of Experimental Research, Sun Yat‐sen University Cancer Center, State Key Laboratory of Oncology in South ChinaCollaborative Innovation Center for Cancer MedicineGuangzhouChina
| | - Muwen Yang
- Department of Experimental Research, Sun Yat‐sen University Cancer Center, State Key Laboratory of Oncology in South ChinaCollaborative Innovation Center for Cancer MedicineGuangzhouChina
| | - Siqi Li
- Department of Experimental Research, Sun Yat‐sen University Cancer Center, State Key Laboratory of Oncology in South ChinaCollaborative Innovation Center for Cancer MedicineGuangzhouChina
- Department of Breast SurgerySun Yat‐sen University Cancer CenterGuangzhouChina
| | - Xiangfu Chen
- Department of Experimental Research, Sun Yat‐sen University Cancer Center, State Key Laboratory of Oncology in South ChinaCollaborative Innovation Center for Cancer MedicineGuangzhouChina
| | - Ying Ouyang
- Department of Experimental Research, Sun Yat‐sen University Cancer Center, State Key Laboratory of Oncology in South ChinaCollaborative Innovation Center for Cancer MedicineGuangzhouChina
| | - Yameng Hu
- Department of Biochemistry, Zhongshan School of MedicineSun Yat‐sen UniversityGuangzhouChina
| | - Xin Chen
- Key Laboratory of Protein Modification and Degradation, School of Basic Medical Sciences; Guangzhou Institute of OncologyTumor Hospital, Guangzhou Medical UniversityGuangzhouChina
| | - Libing Song
- Department of Experimental Research, Sun Yat‐sen University Cancer Center, State Key Laboratory of Oncology in South ChinaCollaborative Innovation Center for Cancer MedicineGuangzhouChina
| | - Runyi Ye
- Department of Thyroid and Breast SurgeryThe First Affiliated Hospital of Sun Yat‐sen UniversityGuangzhouChina
| | - Weidong Wei
- Department of Experimental Research, Sun Yat‐sen University Cancer Center, State Key Laboratory of Oncology in South ChinaCollaborative Innovation Center for Cancer MedicineGuangzhouChina
- Department of Breast SurgerySun Yat‐sen University Cancer CenterGuangzhouChina
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8
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Matos B, Howl J, Jerónimo C, Fardilha M. Modulation of serine/threonine-protein phosphatase 1 (PP1) complexes: A promising approach in cancer treatment. Drug Discov Today 2021; 26:2680-2698. [PMID: 34390863 DOI: 10.1016/j.drudis.2021.08.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2021] [Revised: 04/23/2021] [Accepted: 08/05/2021] [Indexed: 01/21/2023]
Abstract
Cancer is the second leading cause of death worldwide. Despite the availability of numerous therapeutic options, tumor heterogeneity and chemoresistance have limited the success of these treatments, and the development of effective anticancer therapies remains a major focus in oncology research. The serine/threonine-protein phosphatase 1 (PP1) and its complexes have been recognized as potential drug targets. Research on the modulation of PP1 complexes is currently at an early stage, but has immense potential. Chemically diverse compounds have been developed to disrupt or stabilize different PP1 complexes in various cancer types, with the objective of inhibiting disease progression. Beneficial results obtained in vitro now require further pre-clinical and clinical validation. In conclusion, the modulation of PP1 complexes seems to be a promising, albeit challenging, therapeutic strategy for cancer.
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Affiliation(s)
- Bárbara Matos
- Laboratory of Signal Transduction, Department of Medical Sciences, Institute of Biomedicine-iBiMED, University of Aveiro, 3810-193 Aveiro, Portugal; Cancer Biology and Epigenetics Group, IPO Porto Research Center (CI-IPOP), Portuguese Institute of Oncology of Porto (IPO Porto), 4200-072 Porto, Portugal
| | - John Howl
- Molecular Pharmacology Group, Research Institute in Healthcare Science, University of Wolverhampton, Wolverhampton WV1 1LY, UK
| | - Carmen Jerónimo
- Cancer Biology and Epigenetics Group, IPO Porto Research Center (CI-IPOP), Portuguese Institute of Oncology of Porto (IPO Porto), 4200-072 Porto, Portugal; Department of Pathology and Molecular Immunology, Institute of Biomedical Sciences Abel Salazar, University of Porto (ICBAS-UP), 4050-513 Porto, Portugal
| | - Margarida Fardilha
- Laboratory of Signal Transduction, Department of Medical Sciences, Institute of Biomedicine-iBiMED, University of Aveiro, 3810-193 Aveiro, Portugal.
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9
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Lin X, Sajith AM, Wang S, Kumari N, Choy MS, Ahmad A, Cadet DR, Gu X, Ivanov AI, Peti W, Kulkarni A, Nekhai S. Structural Optimization of 2,3-Dihydro-1H-cyclopenta[ b]quinolines Targeting the Noncatalytic RVxF Site of Protein Phosphatase 1 for HIV-1 Inhibition. ACS Infect Dis 2020; 6:3190-3211. [PMID: 33258581 DOI: 10.1021/acsinfecdis.0c00511] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Combination antiretroviral therapy (cART) suppresses human immunodeficiency virus-1 (HIV-1) replication but is unable to permanently eradicate HIV-1. Importantly, cART does not target HIV-1 transcription, which is reactivated in latently infected reservoirs, leading to HIV-1 pathogenesis including non-infectious lung, cardiovascular, kidney, and neurodegenerative diseases. To address the limitations of cART and to prevent HIV-1-related pathogenesis, we developed small molecules to target the noncatalytic RVxF-accommodating site of protein phosphatase-1 (PP1) to prevent HIV-1 transcription activation. The PP1 RVxF-accommodating site is critical for the recruitment of regulatory and substrate proteins to PP1. Here, we confirm that our previously developed 1E7-03 compound binds to the PP1 RVxF-accommodating site. Iterative chemical alterations to 1E7-03 furnished a new analogue, HU-1a, with enhanced HIV-1 inhibitory activity and improved metabolic stability compared to 1E7-03. In a Split NanoBit competition assay, HU-1a primarily bound to the PP1 RVxF-accommodating site. In conclusion, our study identified HU-1a as a promising HIV-1 transcription inhibitor and showed that the PP1 RVxF-accommodating site is a potential drug target for the development of novel HIV-1 transcription inhibitors.
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Affiliation(s)
- Xionghao Lin
- Center for Sickle Cell Disease, College of Medicine, Howard University, Washington, DC 20059, United States
- Department of Oral Pathology, College of Dentistry, Howard University, Washington, DC 20059, United States
| | - Ayyiliath M Sajith
- Department of Pharmaceutical Sciences, College of Pharmacy, Howard University, Washington, DC 20059, United States
| | - Songping Wang
- Center for Sickle Cell Disease, College of Medicine, Howard University, Washington, DC 20059, United States
| | - Namita Kumari
- Center for Sickle Cell Disease, College of Medicine, Howard University, Washington, DC 20059, United States
- Department of Medicine, College of Medicine, Howard University, Washington, DC 20059 United States
| | - Meng S Choy
- Department of Chemistry and Biochemistry, University of Arizona, Tucson, Arizona 85721 United States
| | - Asrar Ahmad
- Center for Sickle Cell Disease, College of Medicine, Howard University, Washington, DC 20059, United States
| | - Dana R. Cadet
- Department of Natural Science, Bowie State University, Bowie, Maryland 20715, United States
| | - Xinbin Gu
- Department of Oral Pathology, College of Dentistry, Howard University, Washington, DC 20059, United States
| | - Andrey I. Ivanov
- Center for Sickle Cell Disease, College of Medicine, Howard University, Washington, DC 20059, United States
| | - Wolfgang Peti
- Department of Chemistry and Biochemistry, University of Arizona, Tucson, Arizona 85721 United States
| | - Amol Kulkarni
- Department of Pharmaceutical Sciences, College of Pharmacy, Howard University, Washington, DC 20059, United States
| | - Sergei Nekhai
- Center for Sickle Cell Disease, College of Medicine, Howard University, Washington, DC 20059, United States
- Department of Medicine, College of Medicine, Howard University, Washington, DC 20059 United States
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10
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Silva JV, Freitas MJ, Santiago J, Jones S, Guimarães S, Vijayaraghavan S, Publicover S, Colombo G, Howl J, Fardilha M. Disruption of protein phosphatase 1 complexes with the use of bioportides as a novel approach to target sperm motility. Fertil Steril 2020; 115:348-362. [PMID: 32977940 DOI: 10.1016/j.fertnstert.2020.08.013] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2020] [Revised: 08/07/2020] [Accepted: 08/07/2020] [Indexed: 01/03/2023]
Abstract
OBJECTIVE To design protein phosphatase 1 (PP1)-disrupting peptides covalently coupled to inert cell-penetrating peptides (CPPs) as sychnologically organized bioportide constructs as a strategy to modulate sperm motility. DESIGN Experimental study. SETTING Academic research laboratory. PATIENT(S)/ANIMAL(S) Normozoospermic men providing samples for routine analysis and Holstein Frisian bulls. INTERVENTION(S) None. MAIN OUTCOME MEASURE(S) Effect of the bioportides on the activity and interactions of PP1γ2-a PP1 isoform expressed exclusively in testicular germ cells and sperm-and on sperm vitality and motility. RESULT(S) PP1-disrupting peptides were designed based on the sequences from: 1) a sperm-specific PP1 interactor (A kinase anchor protein 4); and 2) a PP1 inhibitor (protein phosphatase inhibitor 2). Those sequences were covalently coupled to inert CPPs as bioportide constructs, which were successfully delivered to the flagellum of sperm cells to induce a marked impact on PP1γ2 activity and sperm motility. Molecular modeling studies further facilitated the identification of an optimized PP1-binding sequence and enabled the development of a modified stop-sperm bioportide with reduced size and increased potency of action. In addition, a bioportide mimetic of the unique 22-amino acid C-terminus of PP1γ2 accumulated within spermatozoa to significantly reduce sperm motility and further define the PP1γ2-specific interactome. CONCLUSION(S) These investigations demonstrate the utility of CPPs to deliver peptide sequences that target unique protein-protein interactions in spermatozoa to achieve a significant impact upon spermatozoa motility, a key prognostic indicator of male fertility.
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Affiliation(s)
- Joana Vieira Silva
- Laboratory of Signal Transduction, Department of Medical Sciences, Institute of Biomedicine, University of Aveiro, Aveiro, Portugal; Instituto de Investigação e Inovação em Saúde - i3S, University of Porto, Porto, Portugal; Laboratory of Cell Biology, Unit for Multidisciplinary Research in Biomedicine, Institute of Biomedical Sciences Abel Salazar, University of Porto, Porto, Portugal
| | - Maria João Freitas
- Laboratory of Signal Transduction, Department of Medical Sciences, Institute of Biomedicine, University of Aveiro, Aveiro, Portugal; present address: Laboratory of Protein Phosphorylation and Proteomics, Department of Cellular and Molecular Medicine, Faculty of Medicine, Catholic University of Leuven, Leuven, Belgium
| | - Joana Santiago
- Laboratory of Signal Transduction, Department of Medical Sciences, Institute of Biomedicine, University of Aveiro, Aveiro, Portugal
| | - Sarah Jones
- Research Institute in Healthcare Science, University of Wolverhampton, Wolverhampton, United Kingdom
| | - Sofia Guimarães
- Laboratory of Signal Transduction, Department of Medical Sciences, Institute of Biomedicine, University of Aveiro, Aveiro, Portugal; present address: Instituto de Investigação e Inovação em Saúde, University of Porto, Porto, Portugal
| | | | - Steven Publicover
- School of Biosciences, University of Birmingham, Birmingham, United Kingdom
| | - Giorgio Colombo
- Department of Chemistry, University of Pavia, Pavia, Italy; Istituto di Scienze e Tecnologie Chimiche "Giulio Natta," Consiglio Nazionale delle Ricerche, Milano, Italy
| | - John Howl
- Research Institute in Healthcare Science, University of Wolverhampton, Wolverhampton, United Kingdom
| | - Margarida Fardilha
- Laboratory of Signal Transduction, Department of Medical Sciences, Institute of Biomedicine, University of Aveiro, Aveiro, Portugal.
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11
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Bucko PJ, Scott JD. Drugs That Regulate Local Cell Signaling: AKAP Targeting as a Therapeutic Option. Annu Rev Pharmacol Toxicol 2020; 61:361-379. [PMID: 32628872 DOI: 10.1146/annurev-pharmtox-022420-112134] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Cells respond to environmental cues by mobilizing signal transduction cascades that engage protein kinases and phosphoprotein phosphatases. Correct organization of these enzymes in space and time enables the efficient and precise transmission of chemical signals. The cyclic AMP-dependent protein kinase A is compartmentalized through its association with A-kinase anchoring proteins (AKAPs). AKAPs are a family of multivalent scaffolds that constrain signaling enzymes and effectors at subcellular locations to drive essential physiological events. More recently, it has been recognized that defective signaling in certain endocrine disorders and cancers proceeds through pathological AKAP complexes. Consequently, pharmacologically targeting these macromolecular complexes unlocks new therapeutic opportunities for a growing number of clinical indications. This review highlights recent findings on AKAP signaling in disease, particularly in certain cancers, and offers an overview of peptides and small molecules that locally regulate AKAP-binding partners.
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Affiliation(s)
- Paula J Bucko
- Department of Pharmacology, University of Washington, Seattle, Washington 98195, USA; ,
| | - John D Scott
- Department of Pharmacology, University of Washington, Seattle, Washington 98195, USA; ,
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12
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Ellinger B, Pohlmann D, Woens J, Jäkel FM, Reinshagen J, Stocking C, Prassolov VS, Fehse B, Riecken K. A High-Throughput HIV-1 Drug Screening Platform, Based on Lentiviral Vectors and Compatible with Biosafety Level-1. Viruses 2020; 12:E580. [PMID: 32466195 PMCID: PMC7290285 DOI: 10.3390/v12050580] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2020] [Revised: 05/19/2020] [Accepted: 05/20/2020] [Indexed: 11/17/2022] Open
Abstract
HIV-1 infection is a complex, multi-step process involving not only viral, but also multiple cellular factors. To date, drug discovery methods have primarily focused on the inhibition of single viral proteins. We present an efficient and unbiased approach, compatible with biosafety level 1 (BSL-1) conditions, to identify inhibitors of HIV-1 reverse transcription, intracellular trafficking, nuclear entry and genome integration. Starting with a fluorescent assay setup, we systematically improved the screening methodology in terms of stability, efficiency and pharmacological relevance. Stability and throughput were optimized by switching to a luciferase-based readout. BSL-1 compliance was achieved without sacrificing pharmacological relevance by using lentiviral particles pseudo-typed with the mouse ecotropic envelope protein to transduce human PM1 T cells gene-modified to express the corresponding murine receptor. The cellular assay was used to screen 26,048 compounds selected for maximum diversity from a 200,640-compound in-house library. This yielded z' values greater than 0.8 with a hit rate of 3.3% and a confirmation rate of 50%. We selected 93 hits and enriched the collection with 279 similar compounds from the in-house library to identify promising structural features. The most active compounds were validated using orthogonal assay formats. The similarity of the compound profiles across the different platforms demonstrated that the reported lentiviral assay system is a robust and versatile tool for the identification of novel HIV-1 inhibitors.
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Affiliation(s)
- Bernhard Ellinger
- Department ScreeningPort, Fraunhofer Institute for Molecular Biology and Applied Ecology IME, 22525 Hamburg, Germany; (B.E.); (J.R.)
- Fraunhofer Cluster of Excellence Immune-Mediated Diseases CIMD, Partner site Hamburg, 22525 Hamburg, Germany
| | - Daniel Pohlmann
- Research Department Cell and Gene Therapy, Department of Stem Cell Transplantation, University Medical Center Hamburg-Eppendorf (UKE), 20246 Hamburg, Germany; (D.P.); (J.W.); (F.M.J.); (C.S.)
| | - Jannis Woens
- Research Department Cell and Gene Therapy, Department of Stem Cell Transplantation, University Medical Center Hamburg-Eppendorf (UKE), 20246 Hamburg, Germany; (D.P.); (J.W.); (F.M.J.); (C.S.)
| | - Felix M. Jäkel
- Research Department Cell and Gene Therapy, Department of Stem Cell Transplantation, University Medical Center Hamburg-Eppendorf (UKE), 20246 Hamburg, Germany; (D.P.); (J.W.); (F.M.J.); (C.S.)
| | - Jeanette Reinshagen
- Department ScreeningPort, Fraunhofer Institute for Molecular Biology and Applied Ecology IME, 22525 Hamburg, Germany; (B.E.); (J.R.)
- Fraunhofer Cluster of Excellence Immune-Mediated Diseases CIMD, Partner site Hamburg, 22525 Hamburg, Germany
| | - Carol Stocking
- Research Department Cell and Gene Therapy, Department of Stem Cell Transplantation, University Medical Center Hamburg-Eppendorf (UKE), 20246 Hamburg, Germany; (D.P.); (J.W.); (F.M.J.); (C.S.)
- Heinrich-Pette-Institute, Leibniz Institute for Experimental Virology, 20251 Hamburg, Germany
| | - Vladimir S. Prassolov
- Engelhardt-Institute of Molecular Biology, Russian Academy of Sciences, 117984 Moscow, Russia;
| | - Boris Fehse
- Research Department Cell and Gene Therapy, Department of Stem Cell Transplantation, University Medical Center Hamburg-Eppendorf (UKE), 20246 Hamburg, Germany; (D.P.); (J.W.); (F.M.J.); (C.S.)
- German Center for Infection Research (DZIF), Partner site Hamburg, 20246 Hamburg, Germany
| | - Kristoffer Riecken
- Research Department Cell and Gene Therapy, Department of Stem Cell Transplantation, University Medical Center Hamburg-Eppendorf (UKE), 20246 Hamburg, Germany; (D.P.); (J.W.); (F.M.J.); (C.S.)
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13
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Hashemi P, Sadowski I. Diversity of small molecule HIV-1 latency reversing agents identified in low- and high-throughput small molecule screens. Med Res Rev 2020; 40:881-908. [PMID: 31608481 PMCID: PMC7216841 DOI: 10.1002/med.21638] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2019] [Revised: 08/26/2019] [Accepted: 09/16/2019] [Indexed: 12/12/2022]
Abstract
The latency phenomenon produced by human immunodeficiency virus (HIV-1) prevents viral clearance by current therapies, and consequently development of a cure for HIV-1 disease represents a formidable challenge. Research over the past decade has resulted in identification of small molecules that are capable of exposing HIV-1 latent reservoirs, by reactivation of viral transcription, which is intended to render these infected cells sensitive to elimination by immune defense recognition or apoptosis. Molecules with this capability, known as latency-reversing agents (LRAs) could lead to realization of proposed HIV-1 cure strategies collectively termed "shock and kill," which are intended to eliminate the latently infected population by forced reactivation of virus replication in combination with additional interventions that enhance killing by the immune system or virus-mediated apoptosis. Here, we review efforts to discover novel LRAs via low- and high-throughput small molecule screens, and summarize characteristics and biochemical properties of chemical structures with this activity. We expect this analysis will provide insight toward further research into optimized designs for new classes of more potent LRAs.
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Affiliation(s)
- Pargol Hashemi
- Biochemistry and Molecular Biology, Molecular Epigenetics, Life Sciences InstituteUniversity of British ColumbiaVancouverBritish ColumbiaCanada
| | - Ivan Sadowski
- Biochemistry and Molecular Biology, Molecular Epigenetics, Life Sciences InstituteUniversity of British ColumbiaVancouverBritish ColumbiaCanada
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14
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Ammosova T, Pietzsch CA, Saygideger Y, Ilatovsky A, Lin X, Ivanov A, Kumari N, Jerebtsova M, Kulkarni A, Petukhov M, Üren A, Bukreyev A, Nekhai S. Protein Phosphatase 1-Targeting Small-Molecule C31 Inhibits Ebola Virus Replication. J Infect Dis 2019; 218:S627-S635. [PMID: 30169869 DOI: 10.1093/infdis/jiy422] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Background Ebola virus (EBOV) infection causes severe hemorrhagic fever. EBOV transcription is controlled by host protein phosphatase 1 (PP1), which dephosphorylates VP30 protein. We previously developed 1E7-03, a compound targeting a noncatalytic site of PP1 that induced VP30 phosphorylation and inhibited EBOV transcription. Here, we attempted to further improve 1E7-03, which was not stable in murine serum. Results High-throughput screening with EBOV-green fluorescent protein was conducted on 72 1E7-03 analogs and identified 6 best inhibitory and the least toxic compounds. A parallel in silico screening of compounds from the ZINC database by docking to PP1 identified the best-binding compound C31, which was also present among the top 6 compounds found in the viral screen. C31 showed the best EBOV inhibitory activity among the top 6 compounds and also inhibited EBOV minigenome. C31 bound to the PP1 C-terminal groove in vitro and increased VP30 phosphorylation in cultured cells. C31 demonstrated improved stability in mouse plasma and cell permeability, compared with 1E7-03. It was also detected for 24 hours after injection in mice. Conclusion C31 represents a novel PP1-targeting EBOV inhibitor with improved pharmacological properties that can be further evaluated for future antifiloviral therapy.
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Affiliation(s)
- Tatiana Ammosova
- Center for Sickle Cell Disease, Howard University.,Department of Medicine, Howard University.,Yakut Science Center for Complex Medical Problems, Yakutsk
| | - Colette A Pietzsch
- Department of Pathology, University of Texas Medical Branch at Galveston.,Department of Microbiology and Immunology, University of Texas Medical Branch at Galveston.,Galveston National Laboratory, University of Texas Medical Branch at Galveston
| | - Yasemin Saygideger
- Lombardi Comprehensive Cancer Center, Georgetown University, Washington, D. C
| | - Andrey Ilatovsky
- Division of Molecular and Radiation Biophysics, Petersburg Nuclear Physics Institute, St. Petersburg, Russia
| | - Xionghao Lin
- Center for Sickle Cell Disease, Howard University
| | | | - Namita Kumari
- Center for Sickle Cell Disease, Howard University.,Department of Medicine, Howard University
| | | | | | - Michael Petukhov
- Division of Molecular and Radiation Biophysics, Petersburg Nuclear Physics Institute, St. Petersburg, Russia
| | - Aykut Üren
- Lombardi Comprehensive Cancer Center, Georgetown University, Washington, D. C
| | - Alexander Bukreyev
- Department of Pathology, University of Texas Medical Branch at Galveston.,Department of Microbiology and Immunology, University of Texas Medical Branch at Galveston.,Galveston National Laboratory, University of Texas Medical Branch at Galveston
| | - Sergei Nekhai
- Center for Sickle Cell Disease, Howard University.,Department of Medicine, Howard University.,Department of Microbiology, Howard University
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15
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Lin X, Ammosova T, Choy MS, Pietzsch CA, Ivanov A, Ahmad A, Saygideğer Y, Kumari N, Kovalskyy D, Üren A, Peti W, Bukreyev A, Nekhai S. Targeting the Non-catalytic RVxF Site of Protein Phosphatase-1 With Small Molecules for Ebola Virus Inhibition. Front Microbiol 2019; 10:2145. [PMID: 31572348 PMCID: PMC6753193 DOI: 10.3389/fmicb.2019.02145] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2019] [Accepted: 08/30/2019] [Indexed: 12/17/2022] Open
Abstract
Ebola virus (EBOV) is a non-segmented negative-sense RNA virus that causes a severe human disease. The ongoing EBOV outbreak in the Eastern part of Democratic Republic of the Congo has resulted to date in over 2500 confirmed cases including over 1500 deaths. Difficulties with vaccine administration indicate the necessity for development of new general drugs and therapeutic strategies against EBOV. Host Ser/Thr protein phosphatases, particularly PP1 and PP2A, facilitate EBOV transcription by dephosphorylating the EBOV VP30 protein and switching activity of the polymerase complex toward replication. Previously, we developed small molecule 1E7-03 that targeted host protein phosphatase-1 (PP1) and induces phosphorylation of EBOV VP30 protein thus shifting transcription-replication balance and inhibiting EBOV replication. Here, we developed a new EBOV inhibitor, 1E7-07, that potently inhibits EBOV replication and displays significantly improved metabolic stability when compared to previously described 1E7-03. Proteome analysis of VP30 shows that 1E7-07 increases its phosphorylation on Thr-119 and Ser-124 over 3-fold with p < 0.001, which likely contributes to EBOV inhibition. We analyzed 1E7-07 binding to PP1 using a mass spectrometry-based protein painting approach. Combined with computational docking, protein painting shows that 1E7-07 binds to several PP1 sites including the RVxF site, C-terminal groove and NIPP1-helix binding pocket. Further analysis using surface plasmon resonance and a split NanoBiT system demonstrates that 1E7-07 binds primarily to the RVxF site. Together, detailed analysis of 1E7-07 binding to PP1 and identification of the RVxF site as the main binding site opens up an opportunity for future development of PP1-targeting EBOV inhibitors.
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Affiliation(s)
- Xionghao Lin
- Center for Sickle Cell Disease, College of Medicine, Howard University, Washington, DC, United States
- College of Dentistry, Howard University, Washington, DC, United States
| | - Tatiana Ammosova
- Center for Sickle Cell Disease, College of Medicine, Howard University, Washington, DC, United States
- Department of Medicine, College of Medicine, Howard University, Washington, DC, United States
- Yakut Science Centre of Complex Medical Problems, Yakutsk, Russia
| | - Meng S. Choy
- Department of Chemistry and Biochemistry, University of Arizona, Tucson, AZ, United States
| | - Colette A. Pietzsch
- Department of Pathology, Department of Microbiology and Immunology, and Galveston National Laboratory, University of Texas Medical Branch at Galveston, Galveston, TX, United States
| | - Andrey Ivanov
- Center for Sickle Cell Disease, College of Medicine, Howard University, Washington, DC, United States
| | - Asrar Ahmad
- Center for Sickle Cell Disease, College of Medicine, Howard University, Washington, DC, United States
| | - Yasemin Saygideğer
- Georgetown Lombardi Comprehensive Cancer Center, Georgetown University, Washington, DC, United States
| | - Namita Kumari
- Center for Sickle Cell Disease, College of Medicine, Howard University, Washington, DC, United States
| | - Dmytro Kovalskyy
- Department of Biochemistry, University of Texas Health Science Center, San Antonio, TX, United States
| | - Aykut Üren
- Georgetown Lombardi Comprehensive Cancer Center, Georgetown University, Washington, DC, United States
| | - Wolfgang Peti
- Department of Chemistry and Biochemistry, University of Arizona, Tucson, AZ, United States
| | - Alexander Bukreyev
- Department of Pathology, Department of Microbiology and Immunology, and Galveston National Laboratory, University of Texas Medical Branch at Galveston, Galveston, TX, United States
| | - Sergei Nekhai
- Center for Sickle Cell Disease, College of Medicine, Howard University, Washington, DC, United States
- Department of Medicine, College of Medicine, Howard University, Washington, DC, United States
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16
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Protein Phosphatase 1α Interacts with Venezuelan Equine Encephalitis Virus Capsid Protein and Regulates Viral Replication through Modulation of Capsid Phosphorylation. J Virol 2018; 92:JVI.02068-17. [PMID: 29769351 DOI: 10.1128/jvi.02068-17] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2017] [Accepted: 05/01/2018] [Indexed: 12/11/2022] Open
Abstract
Protein phosphatase 1 (PP1) is a serine/threonine phosphatase which has been implicated in the regulation of a number of viruses, including HIV-1, Ebolavirus, and Rift Valley fever virus. Catalytic subunits of PP1 (PP1α, PP1β, and PP1γ) interact with a host of regulatory subunits and target a wide variety of cellular substrates through a combination of short binding motifs, including an RVxF motif present in the majority of PP1 regulatory subunits. Targeting the RVxF-interacting site on PP1 with the small molecule 1E7-03 inhibits HIV-1, Ebolavirus, and Rift Valley fever virus replication. In this study, we determined the effect of PP1 on Venezuelan equine encephalitis virus (VEEV) replication. Treatment of VEEV-infected cells with 1E7-03 decreased viral replication by more than 2 logs (50% effective concentration [EC50] = 0.6 μM). 1E7-03 treatment reduced viral titers starting at 8 h postinfection. Viral replication was also decreased after treatment with PP1α-targeting small interfering RNA (siRNA). Confocal microscopy demonstrated that PP1α shuttles toward the cytosol during infection with VEEV and that PP1α colocalizes with VEEV capsid. Coimmunoprecipitation experiments confirmed VEEV capsid interaction with PP1α. Furthermore, immunoprecipitation and mass spectrometry data showed that VEEV capsid is phosphorylated and that phosphorylation is moderated by PP1α. Finally, less viral RNA is associated with capsid after treatment with 1E7-03. Coupled with data showing that 1E7-03 inhibits several alphaviruses, this study indicates that inhibition of the PP1α RVxF binding pocket is a promising therapeutic target and provides novel evidence that PP1α modulation of VEEV capsid phosphorylation influences viral replication.IMPORTANCE Venezuelan equine encephalitis virus (VEEV) causes moderate flu-like symptoms and can lead to severe encephalitic disease and potentially death. There are currently no FDA-approved therapeutics or vaccines for human use, and understanding the molecular underpinning of host-virus interactions can aid in the rational design of intervention strategies. The significance of our research is in identifying the interaction between protein phosphatase 1 (PP1) and the viral capsid protein. This interaction is important for viral replication, as inhibition of PP1 results in decrease viral replication. Inhibition of PP1 also inhibited multiple biomedically important alphaviruses, indicating that PP1 may be a potential therapeutic target for alphavirus-induced disease.
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17
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Inhibition of HIV-1 infection in humanized mice and metabolic stability of protein phosphatase-1-targeting small molecule 1E7-03. Oncotarget 2017; 8:76749-76769. [PMID: 29100346 PMCID: PMC5652740 DOI: 10.18632/oncotarget.19999] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2017] [Accepted: 07/14/2017] [Indexed: 01/05/2023] Open
Abstract
We recently identified the protein phosphatase-1 - targeting compound, 1E7-03 which inhibited HIV-1 in vitro. Here, we investigated the effect of 1E7-03 on HIV-1 infection in vivo by analyzing its metabolic stability and antiviral activity of 1E7-03 and its metabolites in HIV-1 infected NSG-humanized mice. 1E7-03 was degraded in serum and formed two major degradation products, DP1 and DP3, which bound protein phosphatase-1 in vitro. However, their anti-viral activities were significantly reduced due to inefficient cell permeability. In cultured cells, 1E7-03 reduced expression of several protein phosphatase-1 regulatory subunits including Sds22 as determined by a label free quantitative proteomics analysis. In HIV-1-infected humanized mice, 1E7-03 significantly reduced plasma HIV-1 RNA levels, similar to the previously described HIV-1 transcription inhibitor F07#13. We synthesized a DP1 analog, DP1-07 with a truncated side chain, which showed improved cell permeability and longer pharmacokinetic retention in mice. But DP1-07 was less efficient than 1E7-03 as a HIV-1 inhibitor both in vitro and in vivo, indicating that the full side chain of 1E7-03 was essential for its anti-HIV activity. Analysis of 1E7-03 stability in plasma and liver microsomes showed that the compound was stable in human, primate and ferret plasma but not in rodent plasma. However, 1E7-03 was not stable in human liver microsomes. Our findings suggest that 1E7-03 is a good candidate for future development of HIV-1 transcription inhibitors. Further structural modification and advanced formulations are needed to improve its metabolic stability and enhance its antiviral activity in non-human primate animals and humans.
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18
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Protein Phosphatase-1 Regulates Expression of Neuregulin-1. BIOLOGY 2016; 5:biology5040049. [PMID: 27918433 PMCID: PMC5192429 DOI: 10.3390/biology5040049] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/30/2016] [Revised: 11/27/2016] [Accepted: 11/29/2016] [Indexed: 01/11/2023]
Abstract
Protein phosphatase 1 (PP1), a cellular serine/threonine phosphatase, is targeted to cellular promoters by its major regulatory subunits, PP1 nuclear targeting subunit, nuclear inhibitor of PP1 (NIPP1) and RepoMan. PP1 is also targeted to RNA polymerase II (RNAPII) by NIPP1 where it can dephosphorylate RNAPII and cycle-dependent kinase 9 (CDK9). Here, we show that treatment of cells with a small molecule activator of PP1 increases the abundance of a neuregulin-1 (NRG-1)-derived peptide. NRG-1 mRNA and protein levels were increased in the cells stably or transiently expressing mutant NIPP1 (mNIPP1) that does not bind PP1, but not in the cells expressing NIPP1. Expression of mNIPP1 also activated the NRG-1 promoter in an NF-κB-dependent manner. Analysis of extracts from mNIPP1 expressing cells by glycerol gradient centrifugation showed a redistribution of PP1 and CDK9 between large and small molecular weight complexes, and increased CDK9 Thr-186 phosphorylation. This correlated with the increased CDK9 activity. Further, RNAPII co-precipitated with mNIPP1, and phosphorylation of RNAPII C-terminal domain (CTD) Ser-2 residues was greater in cells expressing mNIPP1. In mNIPP1 expressing cells, okadaic acid, a cell-permeable inhibitor of PP1, did not increase Ser-2 CTD phosphorylation inhibited by flavopiridol, in contrast to the NIPP1 expressing cells, suggesting that PP1 was no longer involved in RNAPII dephosphorylation. Finally, media conditioned with mNIPP1 cells induced the proliferation of wild type 84-31 cells, consistent with a role of neuregulin-1 as a growth promoting factor. Our study indicates that deregulation of PP1/NIPP1 holoenzyme activates NRG-1 expression through RNAPII and CDK9 phosphorylation in a NF-κB dependent manner.
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Abstract
Phosphatases play key roles in normal physiology and diseases. Studying phosphatases has been both essential and challenging, and the application of conventional genetic and biochemical methods has led to crucial but still limited understanding of their mechanisms, substrates, and exclusive functions within highly intricate networks. With the advances in technologies such as cellular imaging and molecular and chemical biology in terms of sensitive tools and methods, the phosphatase field has thrived in the past years and has set new insights for cell signaling studies and for therapeutic development. In this review, we give an overview of the existing interdisciplinary tools for phosphatases, give examples on how they have been applied to increase our understanding of these enzymes, and suggest how they-and other tools yet barely used in the phosphatase field-might be adapted to address future questions and challenges.
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Affiliation(s)
- Sara Fahs
- European Molecular Biology Laboratory, Genome Biology
Unit, Meyerhofstrasse
1, 69117 Heidelberg, Germany
| | - Pablo Lujan
- European Molecular Biology Laboratory, Genome Biology
Unit, Meyerhofstrasse
1, 69117 Heidelberg, Germany
| | - Maja Köhn
- European Molecular Biology Laboratory, Genome Biology
Unit, Meyerhofstrasse
1, 69117 Heidelberg, Germany
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20
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Recent advances in the identification of Tat-mediated transactivation inhibitors: progressing toward a functional cure of HIV. Future Med Chem 2016; 8:421-42. [PMID: 26933891 DOI: 10.4155/fmc.16.3] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
The current anti-HIV combination therapy does not eradicate the virus that persists mainly in quiescent infected CD4(+) T cells as a latent integrated provirus that resumes after therapy interruption. The Tat-mediated transactivation (TMT) is a critical step in the HIV replication cycle that could give the opportunity to reduce the size of latent reservoirs. More than two decades of research led to the identification of various TMT inhibitors. While none of them met the criteria to reach the market, the search for a suitable TMT inhibitor is still actively pursued. Really promising compounds, including one in a Phase III clinical trial, have been recently identified, thus warranting an update.
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Baer A, Shafagati N, Benedict A, Ammosova T, Ivanov A, Hakami RM, Terasaki K, Makino S, Nekhai S, Kehn-Hall K. Protein Phosphatase-1 regulates Rift Valley fever virus replication. Antiviral Res 2016; 127:79-89. [PMID: 26801627 DOI: 10.1016/j.antiviral.2016.01.007] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2015] [Revised: 12/21/2015] [Accepted: 01/14/2016] [Indexed: 12/21/2022]
Abstract
Rift Valley fever virus (RVFV), genus Phlebovirus family Bunyaviridae, is an arthropod-borne virus endemic throughout sub-Saharan Africa. Recent outbreaks have resulted in cyclic epidemics with an increasing geographic footprint, devastating both livestock and human populations. Despite being recognized as an emerging threat, relatively little is known about the virulence mechanisms and host interactions of RVFV. To date there are no FDA approved therapeutics or vaccines for RVF and there is an urgent need for their development. The Ser/Thr protein phosphatase 1 (PP1) has previously been shown to play a significant role in the replication of several viruses. Here we demonstrate for the first time that PP1 plays a prominent role in RVFV replication early on during the viral life cycle. Both siRNA knockdown of PP1α and a novel PP1-targeting small molecule compound 1E7-03, resulted in decreased viral titers across several cell lines. Deregulation of PP1 was found to inhibit viral RNA production, potentially through the disruption of viral RNA transcript/protein interactions, and indicates a potential link between PP1α and the viral L polymerase and nucleoprotein. These results indicate that PP1 activity is important for RVFV replication early on during the viral life cycle and may prove an attractive therapeutic target.
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Affiliation(s)
- Alan Baer
- National Center for Biodefense and Infectious Diseases, School of Systems Biology, George Mason University, Manassas, VA, USA
| | - Nazly Shafagati
- National Center for Biodefense and Infectious Diseases, School of Systems Biology, George Mason University, Manassas, VA, USA
| | - Ashwini Benedict
- National Center for Biodefense and Infectious Diseases, School of Systems Biology, George Mason University, Manassas, VA, USA
| | - Tatiana Ammosova
- Center for Sickle Cell Disease, Department of Medicine, Howard University, Washington, D.C., USA
| | - Andrey Ivanov
- Center for Sickle Cell Disease, Department of Medicine, Howard University, Washington, D.C., USA
| | - Ramin M Hakami
- National Center for Biodefense and Infectious Diseases, School of Systems Biology, George Mason University, Manassas, VA, USA
| | - Kaori Terasaki
- Department of Microbiology and Immunology, The University of Texas Medical Branch, Galveston, TX, USA
| | - Shinji Makino
- Department of Microbiology and Immunology, The University of Texas Medical Branch, Galveston, TX, USA
| | - Sergei Nekhai
- Center for Sickle Cell Disease, Department of Medicine, Howard University, Washington, D.C., USA
| | - Kylene Kehn-Hall
- National Center for Biodefense and Infectious Diseases, School of Systems Biology, George Mason University, Manassas, VA, USA.
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Tyagi M, Iordanskiy S, Ammosova T, Kumari N, Smith K, Breuer D, Ilatovskiy AV, Kont YS, Ivanov A, Üren A, Kovalskyy D, Petukhov M, Kashanchi F, Nekhai S. Reactivation of latent HIV-1 provirus via targeting protein phosphatase-1. Retrovirology 2015; 12:63. [PMID: 26178009 PMCID: PMC4504130 DOI: 10.1186/s12977-015-0190-4] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2014] [Accepted: 07/09/2015] [Indexed: 11/23/2022] Open
Abstract
Background HIV-1 escapes antiretroviral drugs by integrating into the host DNA and forming a latent transcriptionally silent HIV-1 provirus. This provirus presents the major hurdle in HIV-1 eradication and cure. Transcriptional activation, which is prerequisite for reactivation and the eradication of latent proviruses, is impaired in latently infected T cells due to the lack of host transcription factors, primarily NF-κB and P-TEFb (CDK9/cyclin T1). We and others previously showed that protein phosphatase-1 (PP1) regulates HIV-1 transcription by modulating CDK9 phosphorylation. Recently we have developed a panel of small molecular compounds targeting a non-catalytic site of PP1. Results Here we generated a new class of sulfonamide-containing compounds that activated HIV-1 in acute and latently infected cells. Among the tested molecules, a small molecule activator of PP1 (SMAPP1) induced both HIV-1 replication and reactivation of latent HIV-1 in chronically infected cultured and primary cells. In vitro, SMAPP1 interacted with PP1 and increased PP1 activity toward a recombinant substrate. Treatment with SMAPP1 increased phosphorylation of CDK9’s Ser90 and Thr186 residues, but not Ser175. Proteomic analysis showed upregulation of P-TEFb and PP1 related proteins, including PP1 regulatory subunit Sds22 in SMAPP1-treated T cells. Docking analysis identified a PP1 binding site for SMAPP1 located within the C-terminal binding pocket of PP1. Conclusion We identified a novel class of PP1-targeting compounds that reactivate latent HIV-1 provirus by targeting PP1, increasing CDK9 phosphorylation and enhancing HIV transcription. This compound represents a novel candidate for anti-HIV-1 therapeutics aiming at eradication of latent HIV-1 reservoirs.
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Affiliation(s)
- Mudit Tyagi
- Department of Medicine, The George Washington University, Washington, DC, 2003, USA.
| | - Sergey Iordanskiy
- National Center for Biodefense and Infectious Diseases, George Mason University, Manassas, VA, 20110, USA.
| | - Tatyana Ammosova
- Center for Sickle Cell Disease, Howard University, 1840 7th Street, N.W. HURB1, Suite 202, Washington, DC, 20059, USA. .,Department of Medicine, Howard University, Washington, DC, 20059, USA. .,Yakut Science Center for Complex Medical Problems, Yakutsk, 677019, Russia.
| | - Namita Kumari
- Center for Sickle Cell Disease, Howard University, 1840 7th Street, N.W. HURB1, Suite 202, Washington, DC, 20059, USA.
| | - Kahli Smith
- Center for Sickle Cell Disease, Howard University, 1840 7th Street, N.W. HURB1, Suite 202, Washington, DC, 20059, USA.
| | - Denitra Breuer
- Center for Sickle Cell Disease, Howard University, 1840 7th Street, N.W. HURB1, Suite 202, Washington, DC, 20059, USA.
| | - Andrey V Ilatovskiy
- Division of Molecular and Radiation Biophysics, Petersburg Nuclear Physics Institute, Gatchina, Russia. .,Instiute of Nanobiotechnologies, St. Petersburg State Polytechnical University, St. Petersburg, Russia.
| | | | - Andrey Ivanov
- Center for Sickle Cell Disease, Howard University, 1840 7th Street, N.W. HURB1, Suite 202, Washington, DC, 20059, USA.
| | - Aykut Üren
- Lombardi Comprehensive Cancer Center, Georgetown University, Washington, DC, 20057, USA.
| | - Dmytro Kovalskyy
- Department of Biochemistry and Cancer Therapy and Research Center, University of Texas Health Science Center at San Antonio, 7703 Floyd Curl Drive, San Antonio, TX, 78229, USA.
| | - Michael Petukhov
- Division of Molecular and Radiation Biophysics, Petersburg Nuclear Physics Institute, Gatchina, Russia. .,Instiute of Nanobiotechnologies, St. Petersburg State Polytechnical University, St. Petersburg, Russia.
| | - Fatah Kashanchi
- National Center for Biodefense and Infectious Diseases, George Mason University, Manassas, VA, 20110, USA.
| | - Sergei Nekhai
- Center for Sickle Cell Disease, Howard University, 1840 7th Street, N.W. HURB1, Suite 202, Washington, DC, 20059, USA. .,Department of Medicine, Howard University, Washington, DC, 20059, USA.
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Ammosova T, Platonov M, Ivanov A, Kont YS, Kumari N, Kehn-Hall K, Jerebtsova M, Kulkarni AA, Uren A, Kovalskyy D, Nekhai S. 1E7-03, a low MW compound targeting host protein phosphatase-1, inhibits HIV-1 transcription. Br J Pharmacol 2015; 171:5059-75. [PMID: 25073485 DOI: 10.1111/bph.12863] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2014] [Revised: 06/07/2014] [Accepted: 06/14/2014] [Indexed: 01/20/2023] Open
Abstract
BACKGROUND AND PURPOSE HIV-1 transcription is activated by the Tat protein which recruits the cyclin-dependent kinase CDK9/cyclin T1 to TAR RNA. Tat binds to protein phosphatase-1 (PP1) through the Q(35) VCF(38) sequence and translocates PP1 to the nucleus. PP1 dephosphorylates CDK9 and activates HIV-1 transcription. We have synthesized a low MW compound 1H4, that targets PP1 and prevents HIV-1 Tat interaction with PP1 and inhibits HIV-1 gene transcription. Here, we report our further work with the 1H4-derived compounds and analysis of their mechanism of action. EXPERIMENTAL APPROACH Using the 1H4-PP1 complex as a model, we iteratively designed and synthesized follow-up libraries that were analysed for the inhibition of HIV-1 transcription and toxicity. We also confirmed the mechanism of action of the PP1-targeting molecules by determining the affinity of binding of these molecules to PP1, by analysing their effects on PP1 activity, disruption of PP1 binding to Tat and shuttling of PP1 to the nucleus. KEY RESULTS We identified a tetrahydroquinoline derivative, compound 7, which disrupted the interaction of Tat with PP1. We further optimized compound 7 and obtained compound 7c, renamed 1E7-03, which inhibited HIV-1 with low IC50 (fivefold lower than the previously reported compound, 1H4), showed no cytotoxicity and displayed a plasma half-life greater than 8 h in mice. 1E7-03 bound to PP1 in vitro and prevented shuttling of PP1 into the nucleus. CONCLUSIONS AND IMPLICATIONS Our study shows that low MW compounds that functionally mimic the PP1-binding RVxF peptide can inhibit HIV-1 transcription by deregulating PP1.
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Affiliation(s)
- Tatyana Ammosova
- Center for Sickle Cell Disease, Department of Medicine, Howard University, Washington, DC, USA
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Smith KA, Lin X, Bolshakov O, Griffin J, Niu X, Kovalskyy D, Ivanov A, Jerebtsova M, Taylor RE, Akala E, Nekhai S. Activation of HIV-1 with Nanoparticle-Packaged Small-Molecule Protein Phosphatase-1-Targeting Compound. Sci Pharm 2015; 83:535-48. [PMID: 26839837 PMCID: PMC4727795 DOI: 10.3797/scipharm.1502-01] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2015] [Accepted: 06/22/2015] [Indexed: 11/22/2022] Open
Abstract
Complete eradication of HIV-1 infection is impeded by the existence of latent HIV-1 reservoirs in which the integrated HIV-1 provirus is transcriptionally inactive. Activation of HIV-1 transcription requires the viral Tat protein and host cell factors, including protein phosphatase-1 (PP1). We previously developed a library of small compounds that targeted PP1 and identified a compound, SMAPP1, which induced HIV-1 transcription. However, this compound has a limited bioavailability in vivo and may not be able to reach HIV-1-infected cells and induce HIV-1 transcription in patients. We packaged SMAPP1 in polymeric polyethylene glycol polymethyl methacrylate nanoparticles and analyzed its release and the effect on HIV-1 transcription in a cell culture. SMAPP1 was efficiently packaged in the nanoparticles and released during a 120-hr period. Treatment of the HIV-1-infected cells with the SMAPP1-loaded nanoparticles induced HIV-1 transcription. Thus, nanoparticles loaded with HIV-1-targeting compounds might be useful for future anti-HIV-1 therapeutics.
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Affiliation(s)
- Kahli A Smith
- Center for Sickle Cell Disease, Howard University, Washington DC 20059, USA; Department of Pharmacology, Howard University, Washington DC 20059, USA
| | - Xionghao Lin
- Center for Sickle Cell Disease, Howard University, Washington DC 20059, USA
| | - Oleg Bolshakov
- Department of Pharmaceutical Sciences, Howard University, Washington DC 20059, USA
| | - James Griffin
- College of Engineering, Howard University, Washington DC 20059, USA
| | - Xiaomei Niu
- Center for Sickle Cell Disease, Howard University, Washington DC 20059, USA
| | - Dmytro Kovalskyy
- Department of Biochemistry, School of Medicine, University of Texas Health Science Center at San Antonio, 7703 Floyd Curl Dr., San Antonio TX 78229, USA; Enamine LLC, Princeton Corporate Plaza, 7 Deer Park Drive, Ste. M-3 Monmouth Jct., NJ 08852, USA
| | - Andrey Ivanov
- Center for Sickle Cell Disease, Howard University, Washington DC 20059, USA
| | - Marina Jerebtsova
- Department of Microbiology, College of Medicine, Howard University, Washington DC 20059, USA
| | - Robert E Taylor
- Department of Pharmacology, Howard University, Washington DC 20059, USA
| | - Emmanuel Akala
- Department of Pharmaceutical Sciences, Howard University, Washington DC 20059, USA
| | - Sergei Nekhai
- Center for Sickle Cell Disease, Howard University, Washington DC 20059, USA; Department of Pharmacology, Howard University, Washington DC 20059, USA; Department of Microbiology, College of Medicine, Howard University, Washington DC 20059, USA; Department of Medicine, Howard University, Washington DC 20059, USA
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25
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Jenkins AM, Muskavitch MAT. Evolution of an epigenetic gene ensemble within the genus Anopheles. Genome Biol Evol 2015; 7:901-15. [PMID: 25724208 PMCID: PMC5322554 DOI: 10.1093/gbe/evv041] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Epigenetic control of gene expression has important implications for the regulation of developmental processes, for mediating homeostasis and responses to the external environment, and for transgenerational inheritance of gene expression patterns. Genes that mediate epigenetic control have been well-characterized in Drosophila melanogaster, and we have identified and analyzed an orthologous gene ensemble in Anopheles gambiae that comprises 169 orthologs related to a 215-member epigenetic gene ensemble in D. melanogaster. We find that this ensemble is highly conserved among anopheline mosquitoes, as we identify only seven gene family expansion/contraction events within the ensemble among 12 mosquito species we have studied within the genus Anopheles. Comparative analyses of the epigenetic gene expression across the genera Drosophila and Anopheles reveal distinct tissue-associated expression patterns in the two genera, but similar temporal expression patterns. The A. gambiae complex and D. melanogaster subgroup epigenetic gene ensembles exhibit similar evolutionary rates, as assessed by their respective dN/dS values. These differences in tissue-associated expression patterns, in contrast to similarities in evolutionary rates and temporal expression patterns, may imply that some members of the epigenetic gene ensemble have been redeployed within one or both genera, in comparison to the most recent common ancestor of these two clades. Members of this epigenetic gene ensemble may constitute another set of potential targets for vector control and enable further reductions in the burden of human malaria, by analogy to recent success in development of small molecule antagonists for mammalian epigenetic machinery.
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Affiliation(s)
| | - Marc A T Muskavitch
- Department of Biology, Boston College Discovery Research, Biogen Idec, Cambridge, Massachusetts
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26
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Ilinykh PA, Tigabu B, Ivanov A, Ammosova T, Obukhov Y, Garron T, Kumari N, Kovalskyy D, Platonov MO, Naumchik VS, Freiberg AN, Nekhai S, Bukreyev A. Role of protein phosphatase 1 in dephosphorylation of Ebola virus VP30 protein and its targeting for the inhibition of viral transcription. J Biol Chem 2014; 289:22723-22738. [PMID: 24936058 DOI: 10.1074/jbc.m114.575050] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The filovirus Ebola (EBOV) causes the most severe hemorrhagic fever known. The EBOV RNA-dependent polymerase complex includes a filovirus-specific VP30, which is critical for the transcriptional but not replication activity of EBOV polymerase; to support transcription, VP30 must be in a dephosphorylated form. Here we show that EBOV VP30 is phosphorylated not only at the N-terminal serine clusters identified previously but also at the threonine residues at positions 143 and 146. We also show that host cell protein phosphatase 1 (PP1) controls VP30 dephosphorylation because expression of a PP1-binding peptide cdNIPP1 increased VP30 phosphorylation. Moreover, targeting PP1 mRNA by shRNA resulted in the overexpression of SIPP1, a cytoplasm-shuttling regulatory subunit of PP1, and increased EBOV transcription, suggesting that cytoplasmic accumulation of PP1 induces EBOV transcription. Furthermore, we developed a small molecule compound, 1E7-03, that targeted a non-catalytic site of PP1 and increased VP30 dephosphorylation. The compound inhibited the transcription but increased replication of the viral genome and completely suppressed replication of EBOV in cultured cells. Finally, mutations of Thr(143) and Thr(146) of VP30 significantly inhibited EBOV transcription and strongly induced VP30 phosphorylation in the N-terminal Ser residues 29-46, suggesting a novel mechanism of regulation of VP30 phosphorylation. Our findings suggest that targeting PP1 with small molecules is a feasible approach to achieve dysregulation of the EBOV polymerase activity. This novel approach may be used for the development of antivirals against EBOV and other filovirus species.
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Affiliation(s)
- Philipp A Ilinykh
- Departments of Pathology and University of Texas Medical Branch at Galveston, Galveston, Texas 77555; Galveston National Laboratory, Galveston, Texas 77555
| | - Bersabeh Tigabu
- Departments of Pathology and University of Texas Medical Branch at Galveston, Galveston, Texas 77555; Galveston National Laboratory, Galveston, Texas 77555
| | - Andrey Ivanov
- Center for Sickle Cell Disease and Howard University, Washington, D. C. 20059
| | - Tatiana Ammosova
- Center for Sickle Cell Disease and Howard University, Washington, D. C. 20059; Departments of Medicine and Howard University, Washington, D. C. 20059
| | - Yuri Obukhov
- Center for Sickle Cell Disease and Howard University, Washington, D. C. 20059
| | - Tania Garron
- Departments of Pathology and University of Texas Medical Branch at Galveston, Galveston, Texas 77555; Galveston National Laboratory, Galveston, Texas 77555,; Departments of Microbiology and Immunology, University of Texas Medical Branch at Galveston, Galveston, Texas 77555
| | - Namita Kumari
- Center for Sickle Cell Disease and Howard University, Washington, D. C. 20059
| | - Dmytro Kovalskyy
- Kiev National Taras Shevchenko University, Kiev 01601, Ukraine, and; Enamine Ltd., Kiev 01103, Ukraine
| | - Maxim O Platonov
- Kiev National Taras Shevchenko University, Kiev 01601, Ukraine, and; Enamine Ltd., Kiev 01103, Ukraine
| | - Vasiliy S Naumchik
- Kiev National Taras Shevchenko University, Kiev 01601, Ukraine, and; Enamine Ltd., Kiev 01103, Ukraine
| | - Alexander N Freiberg
- Departments of Pathology and University of Texas Medical Branch at Galveston, Galveston, Texas 77555; Galveston National Laboratory, Galveston, Texas 77555
| | - Sergei Nekhai
- Galveston National Laboratory, Galveston, Texas 77555,; Departments of Medicine and Howard University, Washington, D. C. 20059; Departments of Microbiology, Howard University, Washington, D. C. 20059,.
| | - Alexander Bukreyev
- Departments of Pathology and University of Texas Medical Branch at Galveston, Galveston, Texas 77555; Galveston National Laboratory, Galveston, Texas 77555,; Departments of Microbiology and Immunology, University of Texas Medical Branch at Galveston, Galveston, Texas 77555,.
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Regulation of CDK9 activity by phosphorylation and dephosphorylation. BIOMED RESEARCH INTERNATIONAL 2014; 2014:964964. [PMID: 24524087 PMCID: PMC3913462 DOI: 10.1155/2014/964964] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/20/2013] [Accepted: 12/11/2013] [Indexed: 11/18/2022]
Abstract
HIV-1 transcription is regulated by CDK9/cyclin T1, which, unlike a typical cell cycle-dependent kinase, is regulated by associating with 7SK small nuclear ribonuclear protein complex (snRNP). While the protein components of this complex are well studied, the mechanism of the complex formation is still not fully understood. The association of CDK9/cyclin T1 with 7SK snRNP is, in part, regulated by a reversible CDK9 phosphorylation. Here, we present a comprehensive review of the kinases and phosphatases involved in CDK9 phosphorylation and discuss their role in regulation of HIV-1 replication and potential for being targeted for drug development. We propose a novel pathway of HIV-1 transcription regulation via CDK9 Ser-90 phosphorylation by CDK2 and CDK9 Ser-175 dephosphorylation by protein phosphatase-1.
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Zhang M, Yogesha SD, Mayfield JE, Gill GN, Zhang Y. Viewing serine/threonine protein phosphatases through the eyes of drug designers. FEBS J 2013; 280:4739-60. [PMID: 23937612 DOI: 10.1111/febs.12481] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2013] [Revised: 07/03/2013] [Accepted: 08/02/2013] [Indexed: 01/04/2023]
Abstract
Protein phosphatases, as the counterpart to protein kinases, are essential for homeostatic balance of cell signaling. Small chemical compounds that modulate the specific activity of phosphatases can be powerful tools to elucidate the biological functions of these enzymes. More importantly, many phosphatases are central players in the development of pathological pathways where inactivation can reverse or delay the onset of human diseases. Therefore, potent inhibitors for such phosphatases can be of great therapeutic benefit. In contrast to the seemingly identical enzymatic mechanism and structural characterization of eukaryotic protein kinases, protein phosphatases evolved from diverse ancestors, resulting in different domain architectures, reaction mechanisms and active site properties. In this review, we discuss for each family of serine/threonine protein phosphatases their involvement in biological processes and corresponding strategies for small chemical intervention. Recent advances in modern drug discovery technologies have markedly facilitated the identification of selective inhibitors for some members of the phosphatase family. Furthermore, the rapid growth in knowledge about structure-activity relationships related to possible new drug targets has aided the discovery of natural product inhibitors for the phosphatase family. This review summarizes the current state of investigation of the small molecules that regulate the function of serine/threonine phosphatases, the challenges presented and also strategies to overcome these obstacles.
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Affiliation(s)
- Mengmeng Zhang
- Department of Chemistry and Biochemistry, University of Texas at Austin, TX, USA
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29
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Targeting the untargetable: recent advances in the selective chemical modulation of protein phosphatase-1 activity. Curr Opin Chem Biol 2013; 17:361-8. [PMID: 23647984 DOI: 10.1016/j.cbpa.2013.04.008] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2012] [Revised: 04/04/2013] [Accepted: 04/09/2013] [Indexed: 01/03/2023]
Abstract
Protein phosphatase-1 (PP1) has long been neglected as a potential drug target owing to its misinterpreted unselective nature. However, growing evidence demonstrates that PP1 is highly selective in complex with regulatory proteins at the holoenzyme level, each of which is involved in different essential cellular signaling events. Here we summarize promising approaches to specifically activate or inhibit PP1 activity, and discuss remaining challenges and potential solutions. The summarized chemical tools pave the way for a better understanding of PP1's role in signaling networks, and the effects resulting from their application suggest their potential as future therapeutic candidates.
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30
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Nekhai S, Kumari N, Dhawan S. Role of cellular iron and oxygen in the regulation of HIV-1 infection. Future Virol 2013; 8:301-311. [PMID: 23678366 DOI: 10.2217/fvl.13.6] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Despite efficient antiretroviral therapy, eradication of HIV-1 infection is challenging and requires novel biological insights and therapeutic strategies. Among other physiological and environmental factors, intracellular iron greatly affects HIV-1 replication. Higher iron stores were shown to be associated with faster progression of HIV-1 infection and to inversely correlate with the survival of HIV-1 infected patients. Iron is required for several steps in the HIV-1 life cycle, including reverse transcription, HIV-1 gene expression and capsid assembly. Here, the authors present a comprehensive review of the molecular mechanisms involved in iron- and oxygen-mediated regulation of HIV-1 replication. We also propose key intracellular pathways that may be involved in regulating HIV-1 replication, via protein kinase complexes, CDK9/cyclin T1 and CDK 2/cyclin E, protein phosphatase-1 and other host factors.
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Affiliation(s)
- Sergei Nekhai
- Center for Sickle Cell Disease, Department of Medicine, Howard University, 520 W Street, NW, Washington DC 20059, USA
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De Munter S, Köhn M, Bollen M. Challenges and opportunities in the development of protein phosphatase-directed therapeutics. ACS Chem Biol 2013; 8:36-45. [PMID: 23214403 DOI: 10.1021/cb300597g] [Citation(s) in RCA: 84] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Protein phosphatases have both protective and promoting roles in the etiology of diseases. A prominent example is the existence of oncogenic as well as tumor-suppressing protein phosphatases. A few protein phosphatase activity modulators are already applied in therapies. These were however not developed in target-directed approaches, and the recent discovery of phosphatase involvement followed their application in therapy. Nevertheless, these examples demonstrate that small molecules can be generated that modulate the activity of protein phosphatases and are beneficial for the treatment of protein phosphorylation diseases. We describe here strategies for the development of activators and inhibitors of protein phosphatases and clarify some long-standing misconceptions concerning the druggability of these enzymes. Recent developments suggest that it is feasible to design potent and selective protein phosphatase modulators with a therapeutic potential.
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Affiliation(s)
- Sofie De Munter
- Laboratory of Biosignaling & Therapeutics, Department of Cellular and Molecular Medicine, University of Leuven, Leuven, Belgium
| | - Maja Köhn
- Genome Biology Unit, European Molecular Biology Laboratory, Heidelberg,
Germany
| | - Mathieu Bollen
- Laboratory of Biosignaling & Therapeutics, Department of Cellular and Molecular Medicine, University of Leuven, Leuven, Belgium
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Strategies to Block HIV Transcription: Focus on Small Molecule Tat Inhibitors. BIOLOGY 2012; 1:668-97. [PMID: 24832514 PMCID: PMC4009808 DOI: 10.3390/biology1030668] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/11/2012] [Revised: 11/06/2012] [Accepted: 11/07/2012] [Indexed: 01/29/2023]
Abstract
After entry into the target cell, the human immunodeficiency virus type I (HIV) integrates into the host genome and becomes a proviral eukaryotic transcriptional unit. Transcriptional regulation of provirus gene expression is critical for HIV replication. Basal transcription from the integrated HIV promoter is very low in the absence of the HIV transactivator of transcription (Tat) protein and is solely dependent on cellular transcription factors. The 5' terminal region (+1 to +59) of all HIV mRNAs forms an identical stem-bulge-loop structure called the Transactivation Responsive (TAR) element. Once Tat is made, it binds to TAR and drastically activates transcription from the HIV LTR promoter. Mutations in either the Tat protein or TAR sequence usually affect HIV replication, indicating a strong requirement for their conservation. The necessity of the Tat-mediated transactivation cascade for robust HIV replication renders Tat one of the most desirable targets for transcriptional therapy against HIV replication. Screening based on inhibition of the Tat-TAR interaction has identified a number of potential compounds, but none of them are currently used as therapeutics, partly because these agents are not easily delivered for an efficient therapy, emphasizing the need for small molecule compounds. Here we will give an overview of the different strategies used to inhibit HIV transcription and review the current repertoire of small molecular weight compounds that target HIV transcription.
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