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Yamamoto H, Ryu J, Min E, Oi N, Bai R, Zykova TA, Yu DH, Moriyama K, Bode AM, Dong Z. TRAF1 Is Critical for DMBA/Solar UVR-Induced Skin Carcinogenesis. J Invest Dermatol 2017; 137:1322-1332. [PMID: 28131816 DOI: 10.1016/j.jid.2016.12.026] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2016] [Revised: 12/27/2016] [Accepted: 12/30/2016] [Indexed: 12/15/2022]
Abstract
TRAF1 is a member of the TRAF protein family, which regulates the canonical and noncanonical NF-κB signaling cascades. Although aberrant TRAF1 expression in tumors has been reported, the role of TRAF1 remains elusive. Here, we report that TRAF1 is required for solar UV-induced skin carcinogenesis. Immunohistochemical analysis showed that TRAF1 expression is up-regulated in human actinic keratosis and squamous cell carcinoma. In vivo studies indicated that TRAF1 expression levels in mouse skin are induced by short-term solar UV irradiation, and a long-term skin carcinogenesis study showed that deletion of TRAF1 in mice results in a significant inhibition of skin tumor formation. Moreover, we show that TRAF1 is required for solar UV-induced extracellular signal-regulated kinase-5 (ERK5) phosphorylation and the expression of AP-1 family members (c-Fos/c-Jun). Mechanistic studies showed that TRAF1 expression enhances the ubiquitination of ERK5 on lysine 184, which is necessary for its kinase activity and AP-1 activation. Overall, our results suggest that TRAF1 mediates ERK5 activity by regulating the upstream effectors of ERK5 and also by modulating its ubiquitination status. Targeting TRAF1 function might lead to strategies for preventing and treating skin cancer.
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Affiliation(s)
- Hiroyuki Yamamoto
- The Hormel Institute, University of Minnesota, Austin, Minnesota, USA
| | - Joohyun Ryu
- The Hormel Institute, University of Minnesota, Austin, Minnesota, USA
| | - Eli Min
- The Hormel Institute, University of Minnesota, Austin, Minnesota, USA
| | - Naomi Oi
- The Hormel Institute, University of Minnesota, Austin, Minnesota, USA
| | - Ruihua Bai
- The Hormel Institute, University of Minnesota, Austin, Minnesota, USA
| | - Tatyana A Zykova
- The Hormel Institute, University of Minnesota, Austin, Minnesota, USA
| | - Dong Hoon Yu
- The Hormel Institute, University of Minnesota, Austin, Minnesota, USA
| | - Kenji Moriyama
- Department of Pharmacology, School of Pharmacy and Pharmaceutical Sciences, Mukogawa Women's University, Nishinomiya, Hyogo, Japan
| | - Ann M Bode
- The Hormel Institute, University of Minnesota, Austin, Minnesota, USA
| | - Zigang Dong
- The Hormel Institute, University of Minnesota, Austin, Minnesota, USA.
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Liu C, Luan J, Bai Y, Li Y, Lu L, Liu Y, Hakuno F, Takahashi SI, Duan C, Zhou J. Aspp2 negatively regulates body growth but not developmental timing by modulating IRS signaling in zebrafish embryos. Gen Comp Endocrinol 2014; 197:82-91. [PMID: 24362258 DOI: 10.1016/j.ygcen.2013.12.006] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/17/2013] [Revised: 10/22/2013] [Accepted: 12/10/2013] [Indexed: 10/25/2022]
Abstract
The growth and developmental rate of developing embryos and fetus are tightly controlled and coordinated to maintain proper body shape and size. The insulin receptor substrate (IRS) proteins, key intracellular transducers of insulin and insulin-like growth factor signaling, play essential roles in the regulation of growth and development. A short isoform of apoptosis-stimulating protein of p53 2 (ASPP2) was recently identified as a binding partner of IRS-1 and IRS-2 in mammalian cells in vitro. However, it is unclear whether ASPP2 plays any role in vertebrate embryonic growth and development. Here, we show that zebrafish Aspp2a and Aspp2b negatively regulate embryonic growth without affecting developmental rate. Human ASPP2 had similar effects on body growth in zebrafish embryos. Aspp2a and 2b inhibit Akt signaling. This inhibition was reversed by coinjection of myr-Akt1, a constitutively active form of Akt1. Zebrafish Aspp2a and Aspp2b physically bound with Irs-1, and the growth inhibitory effects of ASPP2/Aspp2 depend on the presence of their ankyrin repeats and SH3 domains. These findings uncover a novel role of Aspp2 in regulating vertebrate embryonic growth.
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Affiliation(s)
- Chengdong Liu
- Key Laboratory of Marine Drugs (Ocean University of China), Chinese Ministry of Education, School of Medicine and Pharmacy, Ocean University of China, Qingdao 266003, China
| | - Jing Luan
- Key Laboratory of Marine Drugs (Ocean University of China), Chinese Ministry of Education, School of Medicine and Pharmacy, Ocean University of China, Qingdao 266003, China
| | - Yan Bai
- Key Laboratory of Marine Drugs (Ocean University of China), Chinese Ministry of Education, School of Medicine and Pharmacy, Ocean University of China, Qingdao 266003, China
| | - Yun Li
- Key Laboratory of Marine Drugs (Ocean University of China), Chinese Ministry of Education, School of Medicine and Pharmacy, Ocean University of China, Qingdao 266003, China
| | - Ling Lu
- Key Laboratory of Marine Drugs (Ocean University of China), Chinese Ministry of Education, School of Medicine and Pharmacy, Ocean University of China, Qingdao 266003, China
| | - Yunzhang Liu
- Key Laboratory of Marine Drugs (Ocean University of China), Chinese Ministry of Education, School of Medicine and Pharmacy, Ocean University of China, Qingdao 266003, China
| | - Fumihiko Hakuno
- Departments of Animal Sciences and Applied Biological Chemistry, Graduate School of Agriculture and Life Sciences, The University of Tokyo, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Shin-Ichiro Takahashi
- Departments of Animal Sciences and Applied Biological Chemistry, Graduate School of Agriculture and Life Sciences, The University of Tokyo, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Cunming Duan
- Department of Molecular, Cellular, and Developmental Biology (C.D.), University of Michigan, Ann Arbor, MI 48109, USA
| | - Jianfeng Zhou
- Key Laboratory of Marine Drugs (Ocean University of China), Chinese Ministry of Education, School of Medicine and Pharmacy, Ocean University of China, Qingdao 266003, China.
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Negahdar M, Aukrust I, Molnes J, Solheim MH, Johansson BB, Sagen JV, Dahl-Jørgensen K, Kulkarni RN, Søvik O, Flatmark T, Njølstad PR, Bjørkhaug L. GCK-MODY diabetes as a protein misfolding disease: the mutation R275C promotes protein misfolding, self-association and cellular degradation. Mol Cell Endocrinol 2014; 382:55-65. [PMID: 24001579 DOI: 10.1016/j.mce.2013.08.020] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/14/2012] [Revised: 08/22/2013] [Accepted: 08/23/2013] [Indexed: 11/28/2022]
Abstract
GCK-MODY, dominantly inherited mild hyperglycemia, is associated with more than 600 mutations in the glucokinase gene. Different molecular mechanisms have been shown to explain GCK-MODY. Here, we report a Pakistani family harboring the glucokinase mutation c.823C>T (p.R275C). The recombinant and in cellulo expressed mutant pancreatic enzyme revealed slightly increased enzyme activity (kcat) and normal affinity for α-D-glucose, and resistance to limited proteolysis by trypsin comparable with wild-type. When stably expressed in HEK293 cells and MIN6 β-cells (at different levels), the mutant protein appeared misfolded and unstable with a propensity to form dimers and aggregates. Its degradation rate was increased, involving the lysosomal and proteasomal quality control systems. On mutation, a hydrogen bond between the R275 side-chain and the carbonyl oxygen of D267 is broken, destabilizing the F260-L271 loop structure and the protein. This promotes the formation of dimers/aggregates and suggests that an increased cellular degradation is the molecular mechanism by which R275C causes GCK-MODY.
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Affiliation(s)
- Maria Negahdar
- KG Jebsen Center for Diabetes Research, Department of Clinical Science, University of Bergen, Bergen, Norway; Center for Medical Genetics and Molecular Medicine, Haukeland University Hospital, Bergen, Norway
| | - Ingvild Aukrust
- KG Jebsen Center for Diabetes Research, Department of Clinical Science, University of Bergen, Bergen, Norway; Center for Medical Genetics and Molecular Medicine, Haukeland University Hospital, Bergen, Norway; Department of Biomedicine, University of Bergen, Bergen, Norway; Section of Islet Cell Biology and Regenerative Medicine, Joslin Diabetes Center, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - Janne Molnes
- KG Jebsen Center for Diabetes Research, Department of Clinical Science, University of Bergen, Bergen, Norway; Department of Biomedicine, University of Bergen, Bergen, Norway; Department of Pediatrics, Haukeland University Hospital, Bergen, Norway
| | - Marie H Solheim
- KG Jebsen Center for Diabetes Research, Department of Clinical Science, University of Bergen, Bergen, Norway; Center for Medical Genetics and Molecular Medicine, Haukeland University Hospital, Bergen, Norway; Department of Biomedicine, University of Bergen, Bergen, Norway
| | - Bente B Johansson
- KG Jebsen Center for Diabetes Research, Department of Clinical Science, University of Bergen, Bergen, Norway; Center for Medical Genetics and Molecular Medicine, Haukeland University Hospital, Bergen, Norway; Department of Pediatrics, Haukeland University Hospital, Bergen, Norway
| | - Jørn V Sagen
- KG Jebsen Center for Diabetes Research, Department of Clinical Science, University of Bergen, Bergen, Norway; Institute of Medicine, University of Bergen, Bergen, Norway; Hormone Laboratory, Haukeland University Hospital, Bergen, Norway
| | - Knut Dahl-Jørgensen
- Pediatric Department Ullevaal, Oslo University Hospital, Oslo, Norway; Faculty of Medicine, University of Oslo, Oslo, Norway
| | - Rohit N Kulkarni
- Section of Islet Cell Biology and Regenerative Medicine, Joslin Diabetes Center, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - Oddmund Søvik
- KG Jebsen Center for Diabetes Research, Department of Clinical Science, University of Bergen, Bergen, Norway
| | | | - Pål R Njølstad
- KG Jebsen Center for Diabetes Research, Department of Clinical Science, University of Bergen, Bergen, Norway; Department of Pediatrics, Haukeland University Hospital, Bergen, Norway.
| | - Lise Bjørkhaug
- KG Jebsen Center for Diabetes Research, Department of Clinical Science, University of Bergen, Bergen, Norway; Center for Medical Genetics and Molecular Medicine, Haukeland University Hospital, Bergen, Norway; Department of Biomedicine, University of Bergen, Bergen, Norway
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Yamamoto T, Tsutsumi N, Tochio H, Ohnishi H, Kubota K, Kato Z, Shirakawa M, Kondo N. Functional assessment of the mutational effects of human IRAK4 and MyD88 genes. Mol Immunol 2014; 58:66-76. [PMID: 24316379 DOI: 10.1016/j.molimm.2013.11.008] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2013] [Revised: 11/08/2013] [Accepted: 11/09/2013] [Indexed: 01/08/2023]
Abstract
Human interleukin-1 receptor-associated kinase 4 (IRAK4) deficiency and myeloid differentiating factor 88 (MyD88) deficiency syndromes are two primary immune-deficiency disorders with innate immune defects. Although new genetic variations of IRAK4 and MyD88 have recently been deposited in the single nucleotide polymorphism (SNP) database, the clinical significance of these variants has not yet been established. Therefore, it is important to establish methods for assessing the association of each gene variation with human diseases. Because cell-based assays, western blotting and an NF-κB reporter gene assay, showed no difference in protein expression and NF-κB activity between R12C and wild-type IRAK4, we examined protein-protein interactions of purified recombinant IRAK4 and MyD88 proteins by analytical gel filtration and NMR titration. We found that the variant of IRAK4, R12C, as well as R20W, located in the death domain of IRAK4 and regarded as a SNP, caused a loss of interaction with MyD88. Our studies suggest that not only the loss of protein expression but also the defect of Myddosome formation could cause IRAK4 and MyD88 deficiency syndromes. Moreover a combination of in vitro functional assays is effective for confirming the pathogenicity of mutants found in IRAK4 and MyD88-deficiency patients.
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El-Sheikh AAK, Greupink R, Wortelboer HM, van den Heuvel JJMW, Schreurs M, Koenderink JB, Masereeuw R, Russel FGM. Interaction of immunosuppressive drugs with human organic anion transporter (OAT) 1 and OAT3, and multidrug resistance-associated protein (MRP) 2 and MRP4. Transl Res 2013; 162:398-409. [PMID: 24036158 DOI: 10.1016/j.trsl.2013.08.003] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/25/2013] [Revised: 08/11/2013] [Accepted: 08/16/2013] [Indexed: 01/30/2023]
Abstract
Renal proximal tubule transporters can play a key role in excretion, pharmacokinetic interactions, and toxicity of immunosuppressant drugs. Basolateral organic anion transporters (OATs) and apical multidrug resistance-associated proteins (MRPs) contribute to the active tubular uptake and urinary efflux of these drugs, respectively. We studied the interaction of 12 immunosuppressants with OAT1- and OAT3-mediated [(3)H]-methotrexate (MTX) uptake in cells, and adenosine triphosphate-dependent [(3)H]-MTX transport in membrane vesicles isolated from human embryonic kidney 293 cells overexpressing human MRP2 and MRP4. Our results show that at a clinically relevant concentration of 10 μM, mycophenolic acid inhibited both OAT1- and OAT3-mediated [(3)H]-MTX uptake. Cytarabine, vinblastine, vincristine, hydrocortisone, and mitoxantrone inhibited only OAT1, whereas tacrolimus, azathioprine, dexamethasone, cyclosporine, and 6-mercaptopurine had no effect on both transporters. Cyclophosphamide stimulated OAT1, but did not affect OAT3. With regard to the apical efflux transporters, mycophenolic acid, cyclophosphamide, hydrocortisone, and tacrolimus inhibited MRP2 and MRP4, whereas mitoxantrone and dexamethasone stimulated [(3)H]-MTX transport by both transporters. Cyclosporine, vincristine, and vinblastine inhibited MRP2 only, whereas 6-mercaptopurine inhibited MRP4 transport activity only. Cytarabine and azathioprine had no effect on either transporter. In conclusion, we charted comprehensively the differences in inhibitory action of various immunosuppressive agents against the 4 key renal anion transporters, and we provide evidence that immunosuppressant drugs can modulate OAT1-, OAT3-, MRP2-, and MRP4-mediated transport of MTX to different extents. The data provide a better understanding of renal mechanisms underlying drug-drug interactions and nephrotoxicity concerning combination regimens with these compounds in the clinic.
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Affiliation(s)
- Azza A K El-Sheikh
- Department of Pharmacology, Faculty of Medicine, Minia University, Minya, Egypt
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6
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Sugiura T, Kageyama S, Andou A, Miyazawa T, Ejima C, Nakayama A, Dohi T, Eda H. Oral treatment with a novel small molecule alpha 4 integrin antagonist, AJM300, prevents the development of experimental colitis in mice. J Crohns Colitis 2013; 7:e533-42. [PMID: 23623333 DOI: 10.1016/j.crohns.2013.03.014] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/05/2012] [Revised: 03/11/2013] [Accepted: 03/28/2013] [Indexed: 12/12/2022]
Abstract
BACKGROUND AND AIMS Inhibition of lymphocyte trafficking by treatment with an anti-α4 integrin antibody has been clinically validated as a therapeutic approach for inflammatory bowel disease (IBD), and the orally effective 'anti-α4 integrin therapy' may be more convenient in clinical practice. The aim of this study was to investigate the pharmacological profile and anti-inflammatory effect of a novel, orally active small molecule α4 integrin antagonist, AJM300. METHODS The binding specificity/potency of HCA2969 (the active metabolite of AJM300) were investigated in vitro. The pharmacodynamics for α4 integrin antagonism of AJM300 was investigated in mice. The anti-inflammatory effect of AJM300 fed in a diet and the anti-α4 integrin monoclonal antibody was evaluated in a mouse colitis model induced by transfer of IL-10 deficient T cells. RESULTS HCA2969 selectively inhibited the in vitro binding of α4 integrin (α4β7/α4β1) to the cell adhesion molecules. Oral treatment with AJM300 dose-dependently inhibited lymphocyte homing to Peyer's patches and increased the peripheral lymphocyte count in the same dose range. AJM300 dose-dependently prevented the development of experimental colitis in mice. A significant inhibition of colon weight increase was accompanied by inhibition of T-cell infiltration into the lamina propria of colon. The maximum efficacy of AJM300 (1% diet) was comparable to that achieved by the saturated α4 integrin blockade with antibody. CONCLUSIONS Oral treatment with the selective small molecule α4 integrin antagonist (AJM300) prevented the development of colitis and its efficacy was comparable to that of the anti-α4 integrin antibody.
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7
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Del Cadia M, De Rienzo F, Weston DA, Thompson AJ, Menziani MC, Lummis SC. Exploring a potential palonosetron allosteric binding site in the 5-HT(3) receptor. Bioorg Med Chem 2013; 21:7523-8. [PMID: 24128813 PMCID: PMC3898987 DOI: 10.1016/j.bmc.2013.09.028] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2013] [Revised: 09/10/2013] [Accepted: 09/11/2013] [Indexed: 11/26/2022]
Abstract
Palonosetron (Aloxi) is a potent second generation 5-HT(3) receptor antagonist whose mechanism of action is not yet fully understood. Palonosetron acts at the 5-HT(3) receptor binding site but recent computational studies indicated other possible sites of action in the extracellular domain. To test this hypothesis we mutated a series of residues in the 5-HT3A receptor subunit (Tyr(73), Phe(130), Ser(163), and Asp(165)) and in the 5-HT3B receptor subunit (His(73), Phe(130), Glu(170), and Tyr(143)) that were previously predicted by in silico docking studies to interact with palonosetron. Homomeric (5-HT(3)A) and heteromeric (5-HT(3)AB) receptors were then expressed in HEK293 cells to determine the potency of palonosetron using both fluorimetric and radioligand methods to test function and ligand binding, respectively. The data show that the substitutions have little or no effect on palonosetron inhibition of 5-HT-evoked responses or binding. In contrast, substitutions in the orthosteric binding site abolish palonosetron binding. Overall, the data support a binding site for palonosetron at the classic orthosteric binding pocket between two 5-HT3A receptor subunits but not at allosteric sites previously identified by in silico modelling and docking.
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Affiliation(s)
- Marta Del Cadia
- Dipartimento di Scienze Chimiche e Geologiche, Università degli Studi di Modena e Reggio Emilia, Via Campi 183, 41100 Modena, Italy
| | - Francesca De Rienzo
- Dipartimento di Scienze Chimiche e Geologiche, Università degli Studi di Modena e Reggio Emilia, Via Campi 183, 41100 Modena, Italy
| | - David A. Weston
- Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge CB2 1QW, UK
| | - Andrew J. Thompson
- Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge CB2 1QW, UK
| | - Maria Cristina Menziani
- Dipartimento di Scienze Chimiche e Geologiche, Università degli Studi di Modena e Reggio Emilia, Via Campi 183, 41100 Modena, Italy
| | - Sarah C.R. Lummis
- Dipartimento di Scienze Chimiche e Geologiche, Università degli Studi di Modena e Reggio Emilia, Via Campi 183, 41100 Modena, Italy
- Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge CB2 1QW, UK
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8
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Smith CJ, McGlade CJ. The ubiquitin ligase RNF126 regulates the retrograde sorting of the cation-independent mannose 6-phosphate receptor. Exp Cell Res 2013; 320:219-32. [PMID: 24275455 DOI: 10.1016/j.yexcr.2013.11.013] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2013] [Revised: 11/13/2013] [Accepted: 11/15/2013] [Indexed: 11/15/2022]
Abstract
The ubiquitin proteasome system is central to the regulation of a number of intracellular sorting pathways in mammalian cells including quality control at the endoplasmic reticulum and the internalization and endosomal sorting of cell surface receptors. Here we describe that RNF126, an E3 ubiquitin ligase, is involved in the sorting of the cation-independent mannose 6-phosphate receptor (CI-MPR). In cells transiently depleted of RNF126, the CI-MPR is dispersed into Rab4 positive endosomes and the efficiency of retrograde sorting is delayed. Furthermore, the stable knockdown of RNF126 leads to the lysosomal degradation of CI-MPR and missorting of cathepsin D. RNF126 specifically regulates the sorting of the CI-MPR as other cargo that follow the retrograde sorting route including the cholera toxin, furin and TGN38 are unaffected in the absence of RNF126. Lastly we show that the RING finger domain of RNF126 is required to rescue the decrease in CI-MPR levels, suggesting that the ubiquitin ligase activity of RNF126 is required for CI-MPR sorting. Together, our data indicate that the ubiquitin ligase RNF126 has a role in the retrograde sorting of the CI-MPR.
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Affiliation(s)
| | - C Jane McGlade
- Department of Medical Biophysics, University of Toronto, Canada; The Arthur and Sonia Labatt Brain Tumour Research Centre, The Hospital for Sick Children, Peter Gilgan Centre for Research and Learning, 686 Bay Street 17-9706, Toronto, Ontario, Canada M5G 0A4.
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Shiratori I, Akitomi J, Boltz DA, Horii K, Furuichi M, Waga I. Selection of DNA aptamers that bind to influenza A viruses with high affinity and broad subtype specificity. Biochem Biophys Res Commun 2013; 443:37-41. [PMID: 24269231 DOI: 10.1016/j.bbrc.2013.11.041] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2013] [Accepted: 11/09/2013] [Indexed: 11/25/2022]
Abstract
Many cases of influenza are reported worldwide every year. The influenza virus often acquires new antigenicity, which is known as antigenic shift; this results in the emergence of new virus strains, for which preexisting immunity is not found in the population resulting in influenza pandemics. In the event a new strain emerges, diagnostic tools must be developed rapidly to detect the novel influenza strain. The generation of high affinity antibodies is costly and takes time; therefore, an alternative detection system, aptamer detection, provides a viable alternative to antibodies as a diagnostic tool. In this study, we developed DNA aptamers that bind to HA1 proteins of multiple influenza A virus subtypes by the SELEX procedure. To evaluate the binding properties of these aptamers using colorimetric methods, we developed a novel aptamer-based sandwich detection method employing our newly identified aptamers. This novel sandwich enzyme-linked aptamer assay successfully detected the H5N1, H1N1, and H3N2 subtypes of influenza A virus with almost equal sensitivities. These findings suggest that our aptamers are attractive candidates for use as simple and sensitive diagnostic tools that need sandwich system for detecting the influenza A virus with broad subtype specificities.
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Affiliation(s)
- Ikuo Shiratori
- VALWAY Technology Center, NEC Soft, Ltd., 1-18-7, Shinkiba Koto-ku, Tokyo 136-8627, Japan.
| | - Joe Akitomi
- VALWAY Technology Center, NEC Soft, Ltd., 1-18-7, Shinkiba Koto-ku, Tokyo 136-8627, Japan
| | - David A Boltz
- Division of Microbiology and Molecular Biology, IIT Research Institute, Illinois Institute of Technology, 10W. 35th Street, Chicago, IL 60616, United States
| | - Katsunori Horii
- VALWAY Technology Center, NEC Soft, Ltd., 1-18-7, Shinkiba Koto-ku, Tokyo 136-8627, Japan
| | - Makio Furuichi
- VALWAY Technology Center, NEC Soft, Ltd., 1-18-7, Shinkiba Koto-ku, Tokyo 136-8627, Japan
| | - Iwao Waga
- VALWAY Technology Center, NEC Soft, Ltd., 1-18-7, Shinkiba Koto-ku, Tokyo 136-8627, Japan
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10
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Miyazaki M, Nishihara H, Hasegawa H, Tashiro M, Wang L, Kimura T, Tanino M, Tsuda M, Tanaka S. NS1-binding protein abrogates the elevation of cell viability by the influenza A virus NS1 protein in association with CRKL. Biochem Biophys Res Commun 2013; 441:953-7. [PMID: 24220336 DOI: 10.1016/j.bbrc.2013.11.011] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2013] [Accepted: 11/01/2013] [Indexed: 10/26/2022]
Abstract
The influenza A virus non-structural protein 1 (NS1) is a multifunctional virulence factor consisting of an RNA binding domain and several Src-homology (SH) 2 and SH3 binding motifs, which promotes virus replication in the host cell and helps to evade antiviral immunity. NS1 modulates general host cell physiology in association with various cellular molecules including NS1-binding protein (NS1-BP) and signaling adapter protein CRK-like (CRKL), while the physiological role of NS1-BP during influenza A virus infection especially in association with NS1 remains unclear. In this study, we analyzed the intracellular association of NS1-BP, NS1 and CRKL to elucidate the physiological roles of these molecules in the host cell. In HEK293T cells, enforced expression of NS1 of A/Beijing (H1N1) and A/Indonesia (H5N1) significantly induced excessive phosphorylation of ERK and elevated cell viability, while the over-expression of NS1-BP and the abrogation of CRKL using siRNA abolished such survival effect of NS1. The pull-down assay using GST-fusion CRKL revealed the formation of intracellular complexes of NS1-BP, NS1 and CRKL. In addition, we identified that the N-terminus SH3 domain of CRKL was essential for binding to NS1-BP using GST-fusion CRKL-truncate mutants. This is the first report to elucidate the novel function of NS1-BP collaborating with viral protein NS1 in modulation of host cell physiology. In addition, an alternative role of adaptor protein CRKL in association with NS1 and NS1-BP during influenza A virus infection is demonstrated.
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Affiliation(s)
- Masaya Miyazaki
- Department of Cancer Pathology, Hokkaido University Graduate School of Medicine, N15W7, Kita-ku, Sapporo 060-8638, Japan
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11
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Randall TS, Moores C, Stephenson FA. Delineation of the TRAK binding regions of the kinesin-1 motor proteins. FEBS Lett 2013; 587:3763-9. [PMID: 24161670 PMCID: PMC3853714 DOI: 10.1016/j.febslet.2013.09.049] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2013] [Revised: 09/30/2013] [Accepted: 09/30/2013] [Indexed: 11/28/2022]
Abstract
TRAK2, a kinesin adaptor protein, binds the cargo binding domain of the kinesin-1 motor, KIF5A. Three KIF5A regions were found to contribute to the TRAK2 binding site. KIF5A discriminates between TRAK1 and TRAK2 with respect to binding specificity. These data yield insights into kinesin/kinesin adaptor protein interactions.
Understanding specific cargo distribution in differentiated cells is a major challenge. Trafficking kinesin proteins (TRAKs) are kinesin adaptors. They bind the cargo binding domain of kinesin-1 motor proteins forming a link between the motor and their cargoes. To refine the TRAK1/2 binding sites within the kinesin-1 cargo domain, rationally designed C-terminal truncations of KIF5A and KIF5C were generated and their co-association with TRAK1/2 determined by quantitative co-immunoprecipitations following co-expression in mammalian cells. Three contributory regions forming the TRAK2 binding site within KIF5A and KIF5C cargo binding domains were delineated. Differences were found between TRAK1/2 with respect to association with KIF5A. TRAK2physically interacts with KIF5C by anti tag coimmunoprecipitation (View interaction) TRAK1physically interacts with KIF5A by anti tag coimmunoprecipitation (View interaction) TRAK2physically interacts with KIF5A by anti tag coimmunoprecipitation (1, 2)
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Affiliation(s)
- Thomas S Randall
- University College London School of Pharmacy, 29/39 Brunswick Square, London WC1N 1AX, United Kingdom
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12
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Rababa'h A, Craft JW, Wijaya CS, Atrooz F, Fan Q, Singh S, Guillory AN, Katsonis P, Lichtarge O, McConnell BK. Protein kinase A and phosphodiesterase-4D3 binding to coding polymorphisms of cardiac muscle anchoring protein (mAKAP). J Mol Biol 2013. [PMID: 23806656 DOI: 10.1016/j.jmb.2013.06.014.] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/30/2022]
Abstract
Protein kinase A (PKA) substrate phosphorylation is facilitated through its co-localization with its signaling partner by A-kinase anchoring proteins (AKAPs). mAKAP (muscle-selective AKAP) localizes PKA and its substrates such as phosphodiesterase-4D3 (PDE4D3), ryanodine receptor, and protein phosphatase 2A (PP2A) to the sarcoplasmic reticulum and perinuclear space. The genetic role of mAKAP, in modulating PKA/PDE4D3 molecular signaling during cardiac diseases, remains unclear. The purpose of this study was to examine the effects of naturally occurring mutations in human mAKAP on PKA and PDE4D3 signaling. We have recently identified potentially important human mAKAP coding non-synonymous polymorphisms located within or near key protein binding sites critical to β-adrenergic receptor signaling. Three mutations (P1400S, S2195F, and L717V) were cloned and transfected into a mammalian cell line for the purpose of comparing whether those substitutions disrupt mAKAP binding to PKA or PDE4D3. Immunoprecipitation study of mAKAP-P1400S, a mutation located in the mAKAP-PDE4D3 binding site, displayed a significant reduction in binding to PDE4D3, with no significant changes in PKA binding or PKA activity. Conversely, mAKAP-S2195F, a mutation located in mAKAP-PP2A binding site, showed significant increase in both binding propensity to PKA and PKA activity. Additionally, mAKAP-L717V, a mutation flanking the mAKAP-spectrin repeat domain, exhibited a significant increase in PKA binding compared to wild type, but there was no change in PKA activity. We also demonstrate specific binding of wild-type mAKAP to PDE4D3. Binding results were demonstrated using immunoprecipitation and confirmed with surface plasmon resonance (Biacore-2000); functional results were demonstrated using activity assays, Ca(2+) measurements, and Western blot. Comparative analysis of the binding responses of mutations to mAKAP could provide important information about how these mutations modulate signaling.
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Affiliation(s)
- Abeer Rababa'h
- Department of Pharmacological and Pharmaceutical Sciences, University of Houston, Texas Medical Center, Houston, TX 77204, USA
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Sherwood AR, Johnson MB, Delgado-Escueta AV, Gentry MS. A bioassay for Lafora disease and laforin glucan phosphatase activity. Clin Biochem 2013; 46:1869-76. [PMID: 24012855 DOI: 10.1016/j.clinbiochem.2013.08.016] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2013] [Revised: 08/21/2013] [Accepted: 08/28/2013] [Indexed: 11/30/2022]
Abstract
OBJECTIVES Lafora disease is a rare yet invariably fatal form of progressive neurodegenerative epilepsy resulting from mutations in the phosphatase laforin. Several therapeutic options for Lafora disease patients are currently being explored, and these therapies would benefit from a biochemical means of assessing functional laforin activity following treatment. To date, only clinical outcomes such as decreases in seizure frequency and severity have been used to indicate success of epilepsy treatment. However, these qualitative measures exhibit variability and must be assessed over long periods of time. In this work, we detail a simple and sensitive bioassay that can be used for the detection of functional endogenous laforin from human and mouse tissue. DESIGN AND METHODS We generated antibodies capable of detecting and immunoprecipitating endogenous laforin. Following laforin immunoprecipitation, laforin activity was assessed via phosphatase assays using para-nitrophenylphosphate (pNPP) and a malachite green-based assay specific for glucan phosphatase activity. RESULTS We found that antibody binding to laforin does not impede laforin activity. Furthermore, the malachite green-based glucan phosphatase assay used in conjunction with a rabbit polyclonal laforin antibody was capable of detecting endogenous laforin activity from human and mouse tissues. Importantly, this assay discriminated between laforin activity and other phosphatases. CONCLUSIONS The bioassay that we have developed utilizing laforin antibodies and an assay specific for glucan phosphatase activity could prove valuable in the rapid detection of functional laforin in patients to which novel Lafora disease therapies have been administered.
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Affiliation(s)
- Amanda R Sherwood
- Department of Molecular and Cellular Biochemistry, Center for Structural Biology, University of Kentucky, Lexington, KY 405036-0001, USA
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Prehm P. Curcumin analogue identified as hyaluronan export inhibitor by virtual docking to the ABC transporter MRP5. Food Chem Toxicol 2013; 62:76-81. [PMID: 23978416 DOI: 10.1016/j.fct.2013.08.028] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2013] [Revised: 08/13/2013] [Accepted: 08/16/2013] [Indexed: 11/29/2022]
Abstract
Hyaluronan is overproduced in many diseases including metastasis, inflammation or ischemia, but there is no drug to attenuate hyaluronan production. Hyaluronan is exported from fibroblasts by the multidrug resistance associated protein 5 (MRP5) which is inhibited by the plant phenols curcumin or xanthohumol. We performed virtual docking and chemical synthesis of analogues to optimize the inhibitors. The AutoDock software was used to identify the binding cavity within the open conformation of MRP5. Inhibitory plant phenols bound to the ATP binding site between the two nucleotide binding domains NBD1 and NBD2. This binding cavity was chosen to screen about 120 derivatives and analogues. The superior hyaluronan export inhibitor was 1,5-bis(4-hydroxy-3-methoxyphenyl)-1,4-pentadien-3-one (hylin). It inhibited hyaluronan export from fibroblasts with an IC50 of 4.9 μM. Hylin is a minor component in natural curcumin preparations and has previously been described as anti-metastatic and anti-inflammatory. Since curcumin itself is unstable under physiological conditions, the active component for many cell biological and pharmaceutical effects of natural curcumin preparations could be hylin that acts by hyaluronan export inhibition.
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Affiliation(s)
- Peter Prehm
- Muenster University Hospital, Institute of Physiological Chemistry and Pathobiochemistry, Waldeyerstrasse 15, D-48149 Muenster, Germany.
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Klementiev B, Enevoldsen MN, Li S, Carlsson R, Liu Y, Issazadeh-Navikas S, Bock E, Berezin V. Antiinflammatory properties of a peptide derived from interleukin-4. Cytokine 2013; 64:112-21. [PMID: 23972727 DOI: 10.1016/j.cyto.2013.07.016] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2013] [Revised: 06/19/2013] [Accepted: 07/20/2013] [Indexed: 12/23/2022]
Abstract
Interleukin-4 (IL-4) is a potent antiinflammatory cytokine. However its use in the clinic is hampered by side effects. We here describe the identification of a novel synthetic peptide, termed Ph8, derived from α-helix C of IL-4, which interacts with IL-4 receptor α (IL-4Rα). Employing various cultured genetically engineered cell lines and primary lymphocytes, surface plasmon resonance, qPCR, ELISA and immunoblotting techniques we found that Ph8 bound IL-4Rα and mimicked the anti-inflammatory effects of IL-4 by inhibiting TNF-α production by macrophages in vitro. It induced phosphorylation of STAT6 65kD but inhibited phosphorylation of STAT6 110 kD induced by IL-4 in a B-cell line that expressed the type I receptor. It also inhibited the IL-4-stimulated expression of a STAT6-inducible reporter gene in cells that expressed the type II receptor. Ph8 inhibited the proliferation of Th1/2 cells and downregulated the production of IFN-γ in stimulated Th1 cells. Moreover, Ph8 did not induce any shift in Th1/Th2 profile. This is a favorable effect and it is indicating that Ph8 could block general T cell activation and inflammatory responses without further inducing the side effects generally associated with IL-4 signaling. These data collectively show that Ph8 is only a partial agonist of IL-4 mimicking its desirable properties. In agreement, Ph8 treatment of rats with collagen-induced arthritis, a Th1- and antibody- mediated disease of joint, delayed the manifestation of chronic inflammation and reduced acute inflammation in carrageenan-induced edema. Our findings indicate that Ph8 is a promising potential drug candidate for the treatment of inflammatory diseases.
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Affiliation(s)
- Boris Klementiev
- Department of Neuroscience and Pharmacology, University of Copenhagen, Copenhagen, Denmark
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16
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Zhou XT, Chen DN, Xie ZQ, Peng Z, Xia KD, Liu HD, Liu W, Su B, Li JD. Functional analysis of the distal region of the third intracellular loop of PROKR2. Biochem Biophys Res Commun 2013; 439:12-7. [PMID: 23969157 DOI: 10.1016/j.bbrc.2013.08.039] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2013] [Accepted: 08/07/2013] [Indexed: 01/09/2023]
Abstract
Mutations in the G-protein-coupled receptor PROKR2 have been identified in patients with idiopathic hypogonadotropic hypogonadism (IHH) and Kallmann syndrome (KS) manifesting with delayed puberty and infertility. Recently, the homozygous mutation V274D was identified in a man displaying KS with an apparent reversal of hypogonadism. The affected amino acid, valine 274, is located at the junction region of the third intracellular loop (IL3) and the sixth transmembrane domain (TM6). In this study, we first studied the effect of V274D and related mutations (V274A, V274T, and V274R) on the signaling activity and cell surface expression of PROKR2. Our data indicate that a charged amino acid substitution at residue 274 of PROKR2 results in low cell surface expression and loss-of-function. Furthermore, we studied the effects of two clusters of basic amino acids located at the proximal region of Val274 on the cell surface expression and function of PROKR2. The deletion of RRK (270-272) resulted in undetectable cell surface expression, whereas RKR (264-266)-deleted PROKR2 was expressed normally on the cell surface but showed loss-of-function due to a deficiency in G-protein coupling. Our data indicate that the distal region of the IL3 of PROKR2 may differentially influence receptor trafficking and G-protein coupling.
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Affiliation(s)
- Xiao-Tao Zhou
- Xiangya Hospital, State Key Laboratory of Medical Genetics, Central South University, Changsha, Hunan Province 410078, PR China; Department of Immunology, Xinjiang Medical University, Urumqi, Xinjiang Uygur Autonomous Region 830054, PR China
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Beltran-Alvarez P, Espejo A, Schmauder R, Beltran C, Mrowka R, Linke T, Batlle M, Pérez-Villa F, Pérez GJ, Scornik FS, Benndorf K, Pagans S, Zimmer T, Brugada R. Protein arginine methyl transferases-3 and -5 increase cell surface expression of cardiac sodium channel. FEBS Lett 2013; 587:3159-65. [PMID: 23912080 DOI: 10.1016/j.febslet.2013.07.043] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2013] [Revised: 07/15/2013] [Accepted: 07/16/2013] [Indexed: 11/20/2022]
Abstract
The α-subunit of the cardiac voltage-gated sodium channel (NaV1.5) plays a central role in cardiomyocyte excitability. We have recently reported that NaV1.5 is post-translationally modified by arginine methylation. Here, we aimed to identify the enzymes that methylate NaV1.5, and to describe the role of arginine methylation on NaV1.5 function. Our results show that protein arginine methyl transferase (PRMT)-3 and -5 methylate NaV1.5 in vitro, interact with NaV1.5 in human embryonic kidney (HEK) cells, and increase NaV1.5 current density by enhancing NaV1.5 cell surface expression. Our observations are the first evidence of regulation of a voltage-gated ion channel, including calcium, potassium, sodium and TRP channels, by arginine methylation.
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Rose KE, Lunardi N, Boscolo A, Dong X, Erisir A, Jevtovic-Todorovic V, Todorovic SM. Immunohistological demonstration of CaV3.2 T-type voltage-gated calcium channel expression in soma of dorsal root ganglion neurons and peripheral axons of rat and mouse. Neuroscience 2013; 250:263-74. [PMID: 23867767 DOI: 10.1016/j.neuroscience.2013.07.005] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2013] [Revised: 06/10/2013] [Accepted: 07/06/2013] [Indexed: 10/26/2022]
Abstract
Previous behavioral studies have revealed that CaV3.2 T-type calcium channels support peripheral nociceptive transmission and electrophysiological studies have established the presence of T-currents in putative nociceptive sensory neurons of dorsal root ganglion (DRG). To date, however, the localization pattern of this key nociceptive channel in the soma and peripheral axons of these cells has not been demonstrated due to lack of isoform-selective anti-CaV3.2 antibodies. In the present study a new polyclonal CaV3.2 antibody is used to localize CaV3.2 expression in rodent DRG neurons using different staining techniques including confocal and electron microscopy (EM). Confocal microscopy of both acutely dissociated cells and short-term cultures demonstrated strong immunofluorescence of anti-CaV3.2 antibody that was largely confined to smaller diameter DRG neurons where it co-localized with established immuno-markers of unmyelinated nociceptors, such as, CGRP, IB4 and peripherin. In contrast, a smaller proportion of these CaV3.2-labeled DRG cells also co-expressed neurofilament 200 (NF200), a marker of myelinated sensory neurons. In the rat sciatic nerve preparation, confocal microscopy demonstrated anti-CaV3.2 immunofluorescence which was co-localized with both peripherin and NF200. Further, EM revealed immuno-gold labeling of CaV3.2 preferentially in association with unmyelinated sensory fibers from mouse sciatic nerve. Finally, we demonstrated the expression of CaV3.2 channels in peripheral nerve endings of mouse hindpaw skin as shown by co-localization with Mrgpd-GFP-positive fibers. The CaV3.2 expression within the soma and peripheral axons of nociceptive sensory neurons further demonstrates the importance of this channel in peripheral pain transmission.
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Affiliation(s)
- K E Rose
- Department of Anesthesiology, University of Virginia, Charlottesville, VA 22908, USA
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Rababa'h A, Craft JW Jr, Wijaya CS, Atrooz F, Fan Q, Singh S, Guillory AN, Katsonis P, Lichtarge O, McConnell BK. Protein kinase A and phosphodiesterase-4D3 binding to coding polymorphisms of cardiac muscle anchoring protein (mAKAP). J Mol Biol 2013; 425:3277-88. [PMID: 23806656 DOI: 10.1016/j.jmb.2013.06.014] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2013] [Revised: 05/20/2013] [Accepted: 06/11/2013] [Indexed: 11/20/2022]
Abstract
Protein kinase A (PKA) substrate phosphorylation is facilitated through its co-localization with its signaling partner by A-kinase anchoring proteins (AKAPs). mAKAP (muscle-selective AKAP) localizes PKA and its substrates such as phosphodiesterase-4D3 (PDE4D3), ryanodine receptor, and protein phosphatase 2A (PP2A) to the sarcoplasmic reticulum and perinuclear space. The genetic role of mAKAP, in modulating PKA/PDE4D3 molecular signaling during cardiac diseases, remains unclear. The purpose of this study was to examine the effects of naturally occurring mutations in human mAKAP on PKA and PDE4D3 signaling. We have recently identified potentially important human mAKAP coding non-synonymous polymorphisms located within or near key protein binding sites critical to β-adrenergic receptor signaling. Three mutations (P1400S, S2195F, and L717V) were cloned and transfected into a mammalian cell line for the purpose of comparing whether those substitutions disrupt mAKAP binding to PKA or PDE4D3. Immunoprecipitation study of mAKAP-P1400S, a mutation located in the mAKAP-PDE4D3 binding site, displayed a significant reduction in binding to PDE4D3, with no significant changes in PKA binding or PKA activity. Conversely, mAKAP-S2195F, a mutation located in mAKAP-PP2A binding site, showed significant increase in both binding propensity to PKA and PKA activity. Additionally, mAKAP-L717V, a mutation flanking the mAKAP-spectrin repeat domain, exhibited a significant increase in PKA binding compared to wild type, but there was no change in PKA activity. We also demonstrate specific binding of wild-type mAKAP to PDE4D3. Binding results were demonstrated using immunoprecipitation and confirmed with surface plasmon resonance (Biacore-2000); functional results were demonstrated using activity assays, Ca(2+) measurements, and Western blot. Comparative analysis of the binding responses of mutations to mAKAP could provide important information about how these mutations modulate signaling.
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Perez-Aso M, Segura V, Montó F, Barettino D, Noguera MA, Milligan G, D'Ocon P. The three α1-adrenoceptor subtypes show different spatio-temporal mechanisms of internalization and ERK1/2 phosphorylation. Biochim Biophys Acta 2013; 1833:2322-33. [PMID: 23797059 DOI: 10.1016/j.bbamcr.2013.06.013] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/14/2012] [Revised: 06/12/2013] [Accepted: 06/13/2013] [Indexed: 12/21/2022]
Abstract
We analyzed the kinetic and spatial patterns characterizing activation of the MAP kinases ERK 1 and 2 (ERK1/2) by the three α1-adrenoceptor (α1-AR) subtypes in HEK293 cells and the contribution of two different pathways to ERK1/2 phosphorylation: protein kinase C (PKC)-dependent ERK1/2 activation and internalization-dependent ERK1/2 activation. The different pathways of phenylephrine induced ERK phosphorylation were determined by western blot, using the PKC inhibitor Ro 31-8425, the receptor internalization inhibitor concanavalin A and the siRNA targeting β-arrestin 2. Receptor internalization properties were studied using CypHer5 technology and VSV-G epitope-tagged receptors. Activation of α1A- and α1B-ARs by phenylephrine elicited rapid ERK1/2 phosphorylation that was directed to the nucleus and inhibited by Ro 31-8425. Concomitant with phenylephrine induced receptor internalization α1A-AR, but not α1B-AR, produced a maintained and PKC-independent ERK phosphorylation, which was restricted to the cytosol and inhibited by β-arrestin 2 knockdown or concanavalin A treatment. α1D-AR displayed constitutive ERK phosphorylation, which was reduced by incubation with prazosin or the selective α1D antagonist BMY7378. Following activation by phenylephrine, α1D-AR elicited rapid, transient ERK1/2 phosphorylation that was restricted to the cytosol and not inhibited by Ro 31-8425. Internalization of the α1D-AR subtype was not observed via CypHer5 technology. The three α1-AR subtypes present different spatio-temporal patterns of receptor internalization, and only α1A-AR stimulation translates to a late, sustained ERK1/2 phosphorylation that is restricted to the cytosol and dependent on β-arrestin 2 mediated internalization.
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Affiliation(s)
- M Perez-Aso
- Departament de Farmacologia, Universitat de València, Spain
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21
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Lummis SCR, Thompson AJ. Agonists and antagonists induce different palonosetron dissociation rates in 5-HT₃A and 5-HT₃AB receptors. Neuropharmacology 2013; 73:241-6. [PMID: 23747573 PMCID: PMC3778450 DOI: 10.1016/j.neuropharm.2013.05.010] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2013] [Revised: 04/19/2013] [Accepted: 05/08/2013] [Indexed: 11/30/2022]
Abstract
Palonosetron is a potent 5-HT3 receptor antagonist with a unique structure and some unusual properties. Here we explore the properties of palonosetron at heterologously expressed 5-HT3A and 5-HT3AB receptors. We used receptors expressed in HEK293 cells, and functionally analysed them using a membrane potential sensitive dye in a Flexstation, which revealed IC50s of 0.24 nM and 0.18 nM for 5-HT3A and 5-HT3AB receptors respectively. Radioligand binding studies with [3H]palonosetron revealed similar Kds: 0.34 nM for 5-HT3A and 0.15 nM for 5-HT3AB receptors. Kinetic studies showed palonosetron association and dissociation rates were slightly faster in 5-HT3AB than 5-HT3A receptors, and for both subtypes dissociation rates were ligand-dependent, with antagonists causing more rapid dissociation than agonists. Similar ligand effects were not observed for [3H]granisetron dissociation studies. These data support previous studies which show palonosetron has actions distinct to other 5-HT3 receptor antagonists, and the slow rates observed for agonist induced dissociation (t1/2 > 10 h) could at least partly explain the long duration of palonosetron effects in vivo. Palonosetron IC50s and Kds for 5-HT3A and 5-HT3AB receptors in HEK293 cells are similar. Palonosetron association and dissociation rates are slower at 5-HT3A than 5-HT3AB receptors. Agonist-induced palonosetron dissociation rates are slower than those for antagonists in both 5-HT3A and 5-HT3AB receptors. Agonist- and antagonist-induced granisetron dissociation rates are similar in both 5-HT3A and 5-HT3AB receptors. Palonosetron and granisetron have distinct actions.
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Affiliation(s)
- Sarah C R Lummis
- Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge CB2 1QW, UK.
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22
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Himmel HM. Drug-induced functional cardiotoxicity screening in stem cell-derived human and mouse cardiomyocytes: effects of reference compounds. J Pharmacol Toxicol Methods 2013; 68:97-111. [PMID: 23702537 DOI: 10.1016/j.vascn.2013.05.005] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2013] [Revised: 05/10/2013] [Accepted: 05/10/2013] [Indexed: 11/30/2022]
Abstract
INTRODUCTION Early prediction of drug-induced functional cardiotoxicity requires robust in-vitro systems suitable for medium/high throughput and easily accessible cardiomyocytes with defined reproducible properties. The xCELLigence Cardio system uses 96-well plates with interdigitated electrodes that detect the impedance changes of rhythmic contractions of stem cell-derived cardiomyocyte (SC-CM) layers. Here, we report on our initial screening experience in comparison to established (multi)cellular and in-vivo models. METHODS Impedance signals from human iPSC-CM (iCells™) and mouse eSC-CM (Cor.At™) were analyzed for contraction amplitude (CA) and duration, rise/fall time, beating rate (BR) and irregularity. RESULTS Following solution exchange, impedance signals re-approximated steady-state conditions after about 2 (Cor.At™) and 3h (iCells™); these time points were used to analyze drug effects. The solvent DMSO (≤1%) hardly influenced contraction parameters in Cor.At™, whereas in iCells™ DMSO (>0.1%) reduced CA and enhanced BR. The selective hERG K⁺ channel blockers E-4031 and dofetilide reduced CA and accelerated BR (≥30 nM) according to the analysis software. The latter, however, was due to burst-like contractions (300 nM) that could be detected only by visual inspection of recordings, and were more pronounced in Cor.At™ as in iCells™. In cardiac myocytes and tissue preparations, however, E4031 and dofetilide have been reported to increase cell shortening and contractile force and to reduce BR. Compounds (pentamidine, HMR1556, ATX2, TTX, and verapamil) with other mechanisms of action were also investigated; their effects differed partially between cell lines (e.g. TTX) and compared to established (multi)cellular models (e.g. HMR1556, ouabain). CONCLUSION Mouse and human stem cell-derived cardiomyocytes respond differently to drugs and these responses occasionally also differ from those originating from established in-vitro and in-vivo models. Hence, drug-induced cardiotoxic effects may be detected with this system, however, the predictive or even translational value of results is considered limited and not yet firmly established.
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Ryšlavá H, Doubnerová V, Kavan D, Vaněk O. Effect of posttranslational modifications on enzyme function and assembly. J Proteomics 2013; 92:80-109. [PMID: 23603109 DOI: 10.1016/j.jprot.2013.03.025] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2012] [Revised: 03/01/2013] [Accepted: 03/11/2013] [Indexed: 12/22/2022]
Abstract
The detailed examination of enzyme molecules by mass spectrometry and other techniques continues to identify hundreds of distinct PTMs. Recently, global analyses of enzymes using methods of contemporary proteomics revealed widespread distribution of PTMs on many key enzymes distributed in all cellular compartments. Critically, patterns of multiple enzymatic and nonenzymatic PTMs within a single enzyme are now functionally evaluated providing a holistic picture of a macromolecule interacting with low molecular mass compounds, some of them being substrates, enzyme regulators, or activated precursors for enzymatic and nonenzymatic PTMs. Multiple PTMs within a single enzyme molecule and their mutual interplays are critical for the regulation of catalytic activity. Full understanding of this regulation will require detailed structural investigation of enzymes, their structural analogs, and their complexes. Further, proteomics is now integrated with molecular genetics, transcriptomics, and other areas leading to systems biology strategies. These allow the functional interrogation of complex enzymatic networks in their natural environment. In the future, one might envisage the use of robust high throughput analytical techniques that will be able to detect multiple PTMs on a global scale of individual proteomes from a number of carefully selected cells and cellular compartments. This article is part of a Special Issue entitled: Posttranslational Protein modifications in biology and Medicine.
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Affiliation(s)
- Helena Ryšlavá
- Department of Biochemistry, Faculty of Science, Charles University in Prague, Hlavova 8, CZ-12840 Prague 2, Czech Republic.
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Lambert DW, Clarke NE, Hooper NM, Turner AJ. Calmodulin interacts with angiotensin-converting enzyme-2 (ACE2) and inhibits shedding of its ectodomain. FEBS Lett 2008; 582:385-90. [PMID: 18070603 PMCID: PMC7094239 DOI: 10.1016/j.febslet.2007.11.085] [Citation(s) in RCA: 99] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2007] [Revised: 11/29/2007] [Accepted: 11/30/2007] [Indexed: 12/15/2022]
Abstract
Angiotensin-converting enzyme-2 (ACE2) is a regulatory protein of the renin-angiotensin system (RAS) and a receptor for the causative agent of severe-acute respiratory syndrome (SARS), the SARS-coronavirus. We have previously shown that ACE2 can be shed from the cell surface in response to phorbol esters by a process involving TNF-alpha converting enzyme (TACE; ADAM17). In this study, we demonstrate that inhibitors of calmodulin also stimulate shedding of the ACE2 ectodomain, a process at least partially mediated by a metalloproteinase. We also show that calmodulin associates with ACE2 and that this interaction is decreased by calmodulin inhibitors.
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Affiliation(s)
- Daniel W Lambert
- Institute of Molecular and Cellular Biology, Faculty of Biological Sciences, University of Leeds, Leeds, UK.
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