1
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Matsuki Y, Saito T, Nakano Y, Hashimoto S, Matsuo Y, Inada T. Crucial role of leaky initiation of uORF3 in the downregulation of HNT1 by ER stress. Biochem Biophys Res Commun 2020; 528:186-192. [PMID: 32475637 DOI: 10.1016/j.bbrc.2020.04.104] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2020] [Accepted: 04/20/2020] [Indexed: 01/27/2023]
Abstract
eIF2α phosphorylation-mediated translational regulation is crucial for global repression of translation by various stresses, including the unfolded protein response (UPR) in eukaryotes. Although translational control during UPR has not been extensively investigated in S. cerevisiae, Hac1-mediated production of long transcripts containing uORFs was shown to repress the translation of histidine triad nucleotide-binding 1 (HNT1) mRNA. The present study showed that uORF3 is required for HNT1 expression, as well as down-regulating HNT1 translation. Translation initiation by uORF3 is inefficient, with uORF3 having a strong Kozak sequence efficiently repressing the translation of HNT1. We propose that leaky scanning of uORF3 is responsible for the downregulation of HNT1 during UPR.
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Affiliation(s)
- Yasuko Matsuki
- Graduate School of Pharmaceutical Science, Tohoku University, Aoba-ku, Sendai, 980-8578, Japan
| | - Taishi Saito
- Graduate School of Pharmaceutical Science, Tohoku University, Aoba-ku, Sendai, 980-8578, Japan
| | - Yu Nakano
- Graduate School of Pharmaceutical Science, Tohoku University, Aoba-ku, Sendai, 980-8578, Japan
| | - Satoshi Hashimoto
- Graduate School of Pharmaceutical Science, Tohoku University, Aoba-ku, Sendai, 980-8578, Japan
| | - Yoshitaka Matsuo
- Graduate School of Pharmaceutical Science, Tohoku University, Aoba-ku, Sendai, 980-8578, Japan
| | - Toshifumi Inada
- Graduate School of Pharmaceutical Science, Tohoku University, Aoba-ku, Sendai, 980-8578, Japan.
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2
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Sjölander JJ, Sunnerhagen P. The fission yeast FHIT homolog affects checkpoint control of proliferation and is regulated by mitochondrial electron transport. Cell Biol Int 2019; 44:412-423. [PMID: 31538680 PMCID: PMC7003880 DOI: 10.1002/cbin.11241] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2019] [Accepted: 09/15/2019] [Indexed: 11/08/2022]
Abstract
Genetic analysis has strongly implicated human FHIT (Fragile Histidine Triad) as a tumor suppressor gene, being mutated in a large proportion of early‐stage cancers. The functions of the FHIT protein have, however, remained elusive. Here, we investigated aph1+, the fission yeast homolog of FHIT, for functions related to checkpoint control and oxidative metabolism. In sublethal concentrations of DNA damaging agents, aph1Δ mutants grew with a substantially shorter lag phase. In aph1Δ mutants carrying a hypomorphic allele of cds1 (the fission yeast homolog of Chk2), in addition, increased chromosome fragmentation and missegregation were found. We also found that under hypoxia or impaired electron transport function, the Aph1 protein level was strongly depressed. Previously, FHIT has been linked to regulation of the human 9‐1‐1 checkpoint complex constituted by Hus1, Rad1, and Rad9. In Schizosaccharomyces pombe, the levels of all three 9‐1‐1 proteins are all downregulated by hypoxia in similarity with Aph1. Moreover, deletion of the aph1+ gene reduced the Rad1 protein level, indicating a direct relationship between these two proteins. We conclude that the fission yeast FHIT homolog has a role in modulating DNA damage checkpoint function, possibly through an effect on the 9‐1‐1 complex, and that this effect may be critical under conditions of limiting oxidative metabolism and reoxygenation.
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Affiliation(s)
- Johanna J Sjölander
- Department of Chemistry and Molecular Biology, Lundberg Laboratory, University of Gothenburg, P.O. Box 462, Göteborg, SE-405 30, Sweden
| | - Per Sunnerhagen
- Department of Chemistry and Molecular Biology, Lundberg Laboratory, University of Gothenburg, P.O. Box 462, Göteborg, SE-405 30, Sweden
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3
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Guo W, Liang X, Liu L, Guo Y, Shen S, Liang J, Dong Z. MiR-6872 host gene SEMA3B and its antisense lncRNA SEMA3B-AS1 function synergistically to suppress gastric cardia adenocarcinoma progression. Gastric Cancer 2019; 22:705-722. [PMID: 30656427 DOI: 10.1007/s10120-019-00924-0] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/01/2018] [Accepted: 01/03/2019] [Indexed: 02/07/2023]
Abstract
BACKGROUND Semaphorin 3B (SEMA3B) is frequently inactivated in several carcinomas. However, as the host gene of miR-6872, the roles of SEMA3B, antisense lncRNA SEMA3B-AS1, and miR-6872 in gastric cardia adenocarcinoma (GCA) tumorigenesis have not been clarified. METHODS The expression levels of SEMA3B, SEMA3B-AS1, and miR-6872 were respectively detected by qRT-PCR, western blot, or immunohistochemical staining assays. The methylation status was determined by BGS and BS-MSP methods. In vitro assays were preformed to explore the biological effects of SEMA3B, SEMA3B-AS1, and miR-6872-5p in gastric cancer cells. Chromatin immunoprecipitation assay was used to detect the binding of protein to DNA. The interaction of SEMA3B-AS1 with MLL4 was identified by RNA immunoprecipitation and RNA pull-down assays. RESULTS Frequent downregulation of SEMA3B, SEMA3B-AS1, and miR-6872 was detected in GCA tissues and gastric cancer cells. Aberrant hypermethylation of the promoter region was more tumor specific and was negatively correlated with the expression level of SEMA3B, SEMA3B-AS1, and miR-6872-5p. Transcription factor Sp1 activated SEMA3B or SEMA3B-AS1 transcription and CpG sites hypermethylation within promoter region eliminated Sp1 binding ability. Overexpression of SEMA3B and SEMA3B-AS1 inhibited gastric cancer cell proliferation, migration, and invasion in vitro. SEMA3B-AS1 induced the expression of SEMA3B by interacting with MLL4. ZNF143 might be the target gene of miR-6872-5p and miR-6872-5p functioning synergistically with SEMA3B to suppress cell invasion. Furthermore, SEMA3B, SEMA3B-AS1, and miR-6872-5p expression levels were associated with GCA patients' survival. CONCLUSIONS SEMA3B, SEMA3B-AS1, and miR-6872 may act as tumor suppressors and may serve as potential targets for antitumor therapy.
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Affiliation(s)
- Wei Guo
- Laboratory of Pathology, Hebei Cancer Institute, The Fourth Hospital of Hebei Medical University, Jiankang Road 12, Shijiazhuang, 050011, Hebei, China
| | - Xiaoliang Liang
- Laboratory of Pathology, Hebei Cancer Institute, The Fourth Hospital of Hebei Medical University, Jiankang Road 12, Shijiazhuang, 050011, Hebei, China
| | - Lei Liu
- Department of Thoracic Surgery, The Fourth Hospital of Hebei Medical University, Shijiazhuang, Hebei, China
| | - Yanli Guo
- Laboratory of Pathology, Hebei Cancer Institute, The Fourth Hospital of Hebei Medical University, Jiankang Road 12, Shijiazhuang, 050011, Hebei, China
| | - Supeng Shen
- Laboratory of Pathology, Hebei Cancer Institute, The Fourth Hospital of Hebei Medical University, Jiankang Road 12, Shijiazhuang, 050011, Hebei, China
| | - Jia Liang
- Laboratory of Pathology, Hebei Cancer Institute, The Fourth Hospital of Hebei Medical University, Jiankang Road 12, Shijiazhuang, 050011, Hebei, China
| | - Zhiming Dong
- Laboratory of Pathology, Hebei Cancer Institute, The Fourth Hospital of Hebei Medical University, Jiankang Road 12, Shijiazhuang, 050011, Hebei, China.
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4
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Bürstner N, Roggo S, Ostermann N, Blank J, Delmas C, Freuler F, Gerhartz B, Hinniger A, Hoepfner D, Liechty B, Mihalic M, Murphy J, Pistorius D, Rottmann M, Thomas JR, Schirle M, Schmitt EK. Gift from Nature: Cyclomarin A Kills Mycobacteria and Malaria Parasites by Distinct Modes of Action. Chembiochem 2015; 16:2433-6. [DOI: 10.1002/cbic.201500472] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2015] [Indexed: 11/11/2022]
Affiliation(s)
- Nathalie Bürstner
- Novartis Institutes for BioMedical Research; Novartis Campus 4056 Basel Switzerland
| | - Silvio Roggo
- Novartis Institutes for BioMedical Research; Novartis Campus 4056 Basel Switzerland
| | - Nils Ostermann
- Novartis Institutes for BioMedical Research; Novartis Campus 4056 Basel Switzerland
| | - Jutta Blank
- Novartis Institutes for BioMedical Research; Novartis Campus 4056 Basel Switzerland
| | - Cecile Delmas
- Novartis Institutes for BioMedical Research; Novartis Campus 4056 Basel Switzerland
| | - Felix Freuler
- Novartis Institutes for BioMedical Research; Novartis Campus 4056 Basel Switzerland
| | - Bernd Gerhartz
- Novartis Institutes for BioMedical Research; Novartis Campus 4056 Basel Switzerland
| | - Alexandra Hinniger
- Novartis Institutes for BioMedical Research; Novartis Campus 4056 Basel Switzerland
| | - Dominic Hoepfner
- Novartis Institutes for BioMedical Research; Novartis Campus 4056 Basel Switzerland
| | - Brigitta Liechty
- Novartis Institutes for BioMedical Research; Novartis Campus 4056 Basel Switzerland
| | - Manuel Mihalic
- Novartis Institutes for BioMedical Research; Novartis Campus 4056 Basel Switzerland
| | - Jason Murphy
- Novartis Institutes for BioMedical Research Inc; 250 Massachusetts Avenue Cambridge MA 02139 USA
| | - Dominik Pistorius
- Novartis Institutes for BioMedical Research; Novartis Campus 4056 Basel Switzerland
| | - Matthias Rottmann
- Swiss Tropical and Public Health Institute; Socinstrasse 57 4051 Basel Switzerland
| | - Jason R. Thomas
- Novartis Institutes for BioMedical Research Inc; 250 Massachusetts Avenue Cambridge MA 02139 USA
| | - Markus Schirle
- Novartis Institutes for BioMedical Research Inc; 250 Massachusetts Avenue Cambridge MA 02139 USA
| | - Esther K. Schmitt
- Novartis Institutes for BioMedical Research; Novartis Campus 4056 Basel Switzerland
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5
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Novel reactivity of Fhit proteins: catalysts for fluorolysis of nucleoside 5'-phosphoramidates and nucleoside 5'-phosphosulfates to generate nucleoside 5'-phosphorofluoridates. Biochem J 2015; 468:337-44. [PMID: 25826698 DOI: 10.1042/bj20141568] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Fragile histidine triad (HIT) proteins (Fhits) occur in all eukaryotes but their function is largely unknown. Human Fhit is presumed to function as a tumour suppressor. Previously, we demonstrated that Fhits catalyse hydrolysis of not only dinucleoside triphosphates but also natural adenosine 5'-phosphoramidate (NH2-pA) and adenosine 5'-phosphosulfate (SO4-pA) as well as synthetic adenosine 5'-phosphorofluoridate (F-pA). In the present study, we describe an Fhit-catalysed displacement of the amino group of nucleoside 5'-phosphoramidates (NH2-pNs) or the sulfate moiety of nucleoside 5'-phosphosulfates (SO4-pNs) by fluoride anion. This results in transient accumulation of the corresponding nucleoside 5'-phosphorofluoridates (F-pNs). Substrate specificity and kinetic characterization of the fluorolytic reactions catalysed by the human Fhit and other examples of involvement of fluoride in the biochemistry of nucleotides are described. Among other HIT proteins, human histidine triad nucleotide-binding protein (Hint1) catalysed fluorolysis of NH2-pA 20 times and human Hint2 40 times more slowly than human Fhit.
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6
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Taverniti V, Séraphin B. Elimination of cap structures generated by mRNA decay involves the new scavenger mRNA decapping enzyme Aph1/FHIT together with DcpS. Nucleic Acids Res 2014; 43:482-92. [PMID: 25432955 PMCID: PMC4288156 DOI: 10.1093/nar/gku1251] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Eukaryotic 5' mRNA cap structures participate to the post-transcriptional control of gene expression before being released by the two main mRNA decay pathways. In the 3'-5' pathway, the exosome generates free cap dinucleotides (m7GpppN) or capped oligoribonucleotides that are hydrolyzed by the Scavenger Decapping Enzyme (DcpS) forming m7GMP. In the 5'-3' pathway, the decapping enzyme Dcp2 generates m7GDP. We investigated the fate of m7GDP and m7GpppN produced by RNA decay in extracts and cells. This defined a pathway involving DcpS, NTPs and the nucleoside diphosphate kinase for m7GDP elimination. Interestingly, we identified and characterized in vitro and in vivo a new scavenger decapping enzyme involved in m7GpppN degradation. We show that activities mediating cap elimination identified in yeast are essentially conserved in human. Their alteration may contribute to pathologies, possibly through the interference of cap (di)nucleotide with cellular function.
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Affiliation(s)
- Valerio Taverniti
- Equipe Labellisée La Ligue, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), Centre National de Recherche Scientifique (CNRS) UMR 7104/Institut National de Santé et de Recherche Médicale (INSERM) U964/Université de Strasbourg, 67404 Illkirch, France
| | - Bertrand Séraphin
- Equipe Labellisée La Ligue, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), Centre National de Recherche Scientifique (CNRS) UMR 7104/Institut National de Santé et de Recherche Médicale (INSERM) U964/Université de Strasbourg, 67404 Illkirch, France
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7
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Guranowski A, Wojdyła AM, Zimny J, Wypijewska A, Kowalska J, Łukaszewicz M, Jemielity J, Darżynkiewicz E, Jagiełło A, Bieganowski P. Recognition of different nucleotidyl-derivatives as substrates of reactions catalyzed by various HIT-proteins. NEW J CHEM 2010. [DOI: 10.1039/b9nj00660e] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
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8
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Guranowski A, Wojdyła AM, Pietrowska-Borek M, Bieganowski P, Khurs EN, Cliff MJ, Blackburn GM, Błaziak D, Stec WJ. Fhit proteins can also recognize substrates other than dinucleoside polyphosphates. FEBS Lett 2008; 582:3152-8. [PMID: 18694747 DOI: 10.1016/j.febslet.2008.07.060] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2008] [Revised: 07/17/2008] [Accepted: 07/31/2008] [Indexed: 11/26/2022]
Abstract
We show here that Fhit proteins, in addition to their function as dinucleoside triphosphate hydrolases, act similarly to adenylylsulfatases and nucleoside phosphoramidases, liberating nucleoside 5'-monophosphates from such natural metabolites as adenosine 5'-phosphosulfate and adenosine 5'-phosphoramidate. Moreover, Fhits recognize synthetic nucleotides, such as adenosine 5'-O-phosphorofluoridate and adenosine 5'-O-(gamma-fluorotriphosphate), and release AMP from them. With respect to the former, Fhits behave like a phosphodiesterase I concomitant with cleavage of the P-F bond. Some kinetic parameters and implications of the novel reactions catalyzed by the human and plant (Arabidopsis thaliana) Fhit proteins are presented.
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Affiliation(s)
- Andrzej Guranowski
- Department of Biochemistry and Biotechnology, The University of Life Sciences, 60-637 Poznań, Poland.
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9
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Campiglio M, Bianchi F, Andriani F, Sozzi G, Tagliabue E, Ménard S, Roz L. Diadenosines as FHIT-ness instructors. J Cell Physiol 2006; 208:274-81. [PMID: 16547961 DOI: 10.1002/jcp.20633] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
FHIT is a tumor suppressor gene that is frequently inactivated in human cancer. Although the Fhit protein is known to hydrolyze diadenosine triphosphate (Ap(3)A), this hydrolase activity is not required for Fhit-mediated oncosuppression. Indeed, the molecular mechanisms and the regulatory elements of Fhit oncosuppression are largely unknown. Here, we review physiological and pathological aspects of Fhit in the context of the Ap(n)A family of signaling molecules, as well as the involvement of Fhit in apoptosis and the cell cycle in cancer models. We also discuss recent findings of novel Fhit interactions that may lead to new hypotheses about biochemical mechanisms underlying the oncosuppressor activity of this gene.
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Affiliation(s)
- Manuela Campiglio
- Department of Experimental Oncology, Molecular Biology Unit, Istituto Nazionale Tumori, Milan, Italy.
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10
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Asensio AC, Rodríguez-Ferrer CR, Oaknin S, Rotllán P. Biochemical and immunochemical characterisation of human diadenosine triphosphatase provides evidence for its identification with the tumour suppressor Fhit protein. Biochimie 2005; 88:461-71. [PMID: 16359767 DOI: 10.1016/j.biochi.2005.10.006] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2005] [Revised: 10/13/2005] [Accepted: 10/14/2005] [Indexed: 02/08/2023]
Abstract
We describe here the purification and characterisation of the human enzyme diadenosine triphosphatase isolated from human platelets and leukocytes, offering biochemical and immunochemical evidence to identify this enzyme with the novel tumour suppressor Fhit protein, a homodimer composed of approximately 17 kDa monomers. It catalyses the Mg(2+)-dependent hydrolysis of diadenosine triphosphate, Ap(3)A, to AMP+ADP. The fluorogenic substrate di-ethenoadenosine triphosphate, epsilon-(Ap(3)A), and Fhit antibodies were used for enzymatic and immunochemical characterisations, respectively. Human Ap(3)Aase presents a native molecular mass of approximately 32 kDa and no significant differences were found in K(m) values (2 microM), activating effects by Mg(2+), Ca(2+), and Mn(2+), optimum pH (7.0-7.2) or inhibition by Zn(2+) and diethyl pyrocarbonate between the human enzyme and the recombinant Fhit protein. Suramin is a very potent competitive inhibitor of both human Ap(3)Aase and Fhit protein with K(i) values in the range 20-30 nM. Both human and rat Ap(3)Aase activity co-purifies with Fhit immunoreactivity under gel filtration, ion-exchange and affinity chromatography. Homogeneous human Ap(3)Aase preparations analysed by SDS-PAGE and Western blot analysis with Fhit antibodies elicit immunochemical responses corresponding to a approximately 17 kDa polypeptide, indicating a dimeric structure for the enzyme Ap(3)Aase. The strong inhibition of Fhit enzyme by the drug suramin, supports the need to investigate the therapeutic potential of Fhit-Ap(3)Aase mediated by its interaction with suramin or related drugs.
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Affiliation(s)
- Aaron C Asensio
- Departamento de Bioquímica y Biología Molecular, Universidad de La Laguna, 38206 La Laguna, Canary Islands, Spain
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11
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Golebiowski F, Szulc A, Szutowicz A, Pawelczyk T. Ubc9-induced inhibition of diadenosine triphosphate hydrolase activity of the putative tumor suppressor protein Fhit. Arch Biochem Biophys 2004; 428:160-4. [PMID: 15246872 DOI: 10.1016/j.abb.2004.05.020] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2004] [Revised: 05/07/2004] [Indexed: 11/21/2022]
Abstract
Fhit protein is the product of the putative tumor suppressor fragile histidine triad (FHIT) gene. The way by which Fhit exerts its antitumor activity remains largely unknown, although the Fhit-Ap3A complex is believed to be the native signaling form of Fhit. Here, we have shown that Fhit protein interacts with hUbc9, a recombinant human SUMO-1 conjugating enzyme, in an adenosine(5')triphospho(5')nucleoside (Ap3N)-dependent manner. Our experiments showed that the dinucleoside polyphosphate hydrolase activity of Fhit is suppressed by interacting with hUbc9 protein. In the presence of equimolar hUbc9 the Vmax and Km activity of Fhit was decreased by 35%. Analysis of Fhit kinetics in the presence of different fixed concentrations of Ubc9 showed that Ubc9 is an uncompetitive inhibitor. Including SUMO-1 protein in the assay neither affected the Fhit activity nor modified the effect of Ubc9 on Fhit kinetics. Our data suggest that hUbc9-induced inhibition of Fhit may result in an elongation of the Fhit-Ap3A signaling complex lifetime leading to alteration of its antitumor activity.
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Affiliation(s)
- Filip Golebiowski
- Department of Molecular Medicine, Medical University of Gdansk, 80-211 Gdansk, Poland
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12
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Korsisaari N, Rossi DJ, Luukko K, Huebner K, Henkemeyer M, Mäkelä TP. The histidine triad protein Hint is not required for murine development or Cdk7 function. Mol Cell Biol 2003; 23:3929-35. [PMID: 12748294 PMCID: PMC155213 DOI: 10.1128/mcb.23.11.3929-3935.2003] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The histidine triad (HIT) protein Hint has been found to associate with mammalian Cdk7, as well as to interact both physically and genetically with the budding yeast Cdk7 homologue Kin28. To study the function of Hint and to explore its possible role in modulating Cdk7 activity in vivo, we have characterized the expression pattern of murine Hint and generated Hint-deficient (Hint(-/-)) mice. Hint was widely expressed during mouse development, with pronounced expression in several neuronal ganglia, epithelia, hearts, and testes from embryonic day 15 onward. Despite this widespread expression, disruption of Hint did not impair murine development. Moreover, Hint-deficient mice had a normal life span and were apparently healthy. Histological examination of tissues with high Hint expression in wild-type animals did not show signs of abnormal pathology in Hint(-/-) mice. Functional redundancy within the HIT family was addressed by crossing Hint(-/-) mice with mice lacking the related HIT protein, Fhit, and by assaying the expression levels of the HIT protein gene family members Hint2 and Hint3 in Hint(+/+) and Hint(-/-) tissues. Finally, Cdk7 kinase activity and cell cycle kinetics were found to be comparable in wild-type and Hint(-/-) mouse embryonic fibroblasts, suggesting that Hint may not be a key regulator of Cdk7 activity.
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Affiliation(s)
- Nina Korsisaari
- Haartman Institute and Helsinki University Central Hospital, Biomedicum Helsinki, 00014 University of Helsinki, Finland
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13
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Brenner C. Hint, Fhit, and GalT: function, structure, evolution, and mechanism of three branches of the histidine triad superfamily of nucleotide hydrolases and transferases. Biochemistry 2002; 41:9003-14. [PMID: 12119013 PMCID: PMC2571077 DOI: 10.1021/bi025942q] [Citation(s) in RCA: 226] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
HIT (histidine triad) proteins, named for a motif related to the sequence HphiHphiHphiphi (phi, a hydrophobic amino acid), are a superfamily of nucleotide hydrolases and transferases, which act on the alpha-phosphate of ribonucleotides, and contain a approximately 30 kDa domain that is typically either a homodimer of approximately 15 kDa polypeptides with two active-sites or an internally, imperfectly repeated polypeptide that retains a single HIT active site. On the basis of sequence, substrate specificity, structure, evolution, and mechanism, HIT proteins can be classified into the Hint branch, which consists of adenosine 5'-monophosphoramide hydrolases, the Fhit branch, which consists of diadenosine polyphosphate hydrolases, and the GalT branch, which consists of specific nucleoside monophosphate transferases, including galactose-1-phosphate uridylyltransferase, diadenosine tetraphosphate phosphorylase, and adenylyl sulfate:phosphate adenylytransferase. At least one human representative of each branch is lost in human diseases. Aprataxin, a Hint branch hydrolase, is mutated in ataxia-oculomotor apraxia syndrome. Fhit is lost early in the development of many epithelially derived tumors. GalT is deficient in galactosemia. Additionally, ASW is an avian Hint family member that has evolved to have unusual gene expression properties and the complete loss of its nucleotide binding site. The potential roles of ASW and Hint in avian sexual development are discussed elsewhere. Here we review what is known about biological activities of HIT proteins, the structural and biochemical bases for their functions, and propose a new enzyme mechanism for Hint and Fhit that may account for the differences between HIT hydrolases and transferases.
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Affiliation(s)
- Charles Brenner
- Structural Biology and Bioinformatics Program, Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, Pennsylvania 19107, USA.
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14
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Rubio-Texeira M, Varnum JM, Bieganowski P, Brenner C. Control of dinucleoside polyphosphates by the FHIT-homologous HNT2 gene, adenine biosynthesis and heat shock in Saccharomyces cerevisiae. BMC Mol Biol 2002; 3:7. [PMID: 12028594 PMCID: PMC116438 DOI: 10.1186/1471-2199-3-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2002] [Accepted: 05/20/2002] [Indexed: 11/24/2022] Open
Abstract
BACKGROUND The FHIT gene is lost early in the development of many tumors. Fhit possesses intrinsic ApppA hydrolase activity though ApppA cleavage is not required for tumor suppression. Because a mutant form of Fhit that is functional in tumor suppression and defective in catalysis binds ApppA well, it was hypothesized that Fhit-substrate complexes are the active, signaling form of Fhit. Which substrates are most important for Fhit signaling remain unknown. RESULTS Here we demonstrate that dinucleoside polyphosphate levels increase 500-fold to hundreds of micromolar in strains devoid of the Saccharomyces cerevisiae homolog of Fhit, Hnt2. Accumulation of dinucleoside polyphosphates is reversed by re-expression of Hnt2 and is active site-dependent. Dinucleoside polyphosphate levels depend on an intact adenine biosynthetic pathway and time in liquid culture, and are induced by heat shock to greater than 0.1 millimolar even in Hnt2+ cells. CONCLUSIONS The data indicate that Hnt2 hydrolyzes both ApppN and AppppN in vivo and that, in heat-shocked, adenine prototrophic yeast strains, dinucleoside polyphosphates accumulate to levels in which they may saturate Hnt2.
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Affiliation(s)
- Marta Rubio-Texeira
- Structural Biology & Bioinformatics Program, Kimmel Cancer Center, Philadelphia, Pennsylvania, USA
- Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - James M Varnum
- Structural Biology & Bioinformatics Program, Kimmel Cancer Center, Philadelphia, Pennsylvania, USA
| | - Pawel Bieganowski
- Structural Biology & Bioinformatics Program, Kimmel Cancer Center, Philadelphia, Pennsylvania, USA
| | - Charles Brenner
- Structural Biology & Bioinformatics Program, Kimmel Cancer Center, Philadelphia, Pennsylvania, USA
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15
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Korsisaari N, Mäkelä TP. Interactions of Cdk7 and Kin28 with Hint/PKCI-1 and Hnt1 histidine triad proteins. J Biol Chem 2000; 275:34837-40. [PMID: 10958787 DOI: 10.1074/jbc.c000505200] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Cyclin-dependent kinase 7 (Cdk7) forms a trimeric complex with cyclin H and Mat1 to form the mammalian Cdk-activating kinase, CAK, as well as a part of the basal transcription factor TFIIH, where Cdk7 phosphorylates the C-terminal domain (CTD) of the large subunit of RNA polymerase II. Here, we report a novel interaction between Cdk7 and a histidine triad (HIT) family protein, Hint/PKCI-1. This interaction was initially observed in a yeast two-hybrid study and subsequently verified by co-immunoprecipitation and subcellular localization studies, where overexpression of Cdk7 leads to partial relocalization of Hint to the nucleus. The physical association is independent of cyclin H binding or Cdk7 kinase activity and is conserved between the related Sacharomyces cerevisiae CTD kinase Kin28 and the HIT protein Hnt1. Furthermore, combination of a disruption of HNT1 and a KIN28 temperature-sensitive allele in S. cerevisiae led to highly elongated cell morphology and reduced colony formation, indicating a genetic interaction between KIN28 and HNT1. The physical and genetic interactions of Hint and Hnt1 with Cdk7 and Kin28 suggest a role for this class of histidine triad proteins in the regulation of Cdk7 and Kin28 functions.
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Affiliation(s)
- N Korsisaari
- Haartman Institute & Biocentrum Helsinki, P. O. Box 21, University of Helsinki, 00014 Helsinki, Finland
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16
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Ingram SW, Barnes LD. Disruption and overexpression of the Schizosaccharomyces pombe aph1 gene and the effects on intracellular diadenosine 5',5'''-P1, P4-tetraphosphate (Ap4A), ATP and ADP concentrations. Biochem J 2000; 350 Pt 3:663-9. [PMID: 10970777 PMCID: PMC1221295] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/17/2023]
Abstract
Diadenosine oligophosphates are ubiquitous compounds that were discovered over 30 years ago. Diadenosine 5',5"'-P(1), P(4)-tetraphosphate (Ap(4)A) is the most studied member of this family, and its function in yeast is unknown. To investigate possible functions, we changed the intracellular Ap(4)A concentration in Schizosaccharomyces pombe via disruption and overexpression of the aph1 gene, which encodes an Ap(4)A hydrolase (Aph1). S. pombe Aph1 is 52% identical with a human tumour suppressor protein, Fhit, in a core region of 109 amino acids. Disruption of aph1 resulted in an 85% decrease in Ap(4)A hydrolase activity and a 290-fold increase in the intracellular Ap(4)A concentration. The disruption and subsequent increase in intracellular Ap(4)A concentration had no significant effect on the growth of S. pombe. Overexpression of the S. pombe aph1 gene, resulting in 17- and 84-fold increases in Ap(4)A hydrolase activity above wild-type levels, resulted in 60 and 80% decreases respectively in the intracellular Ap(4)A concentration. This represents the first report of a decrease in the intracellular Ap(4)A concentration in response to overexpression of a degradative enzyme in any eukaryotic organism. We describe a new S. pombe expression plasmid, pPOX, which was used to achieve the largest increase in expression of aph1. Overexpression of aph1 at the highest level resulted in a 46% increase in generation time in comparison with the control strain. Neither overexpression nor disruption had any effect on the intracellular ATP or ADP concentrations. This is the first report of ADP and ATP concentrations in S. pombe. These data also indicate that Aph1 functions in vivo to degrade Ap(4)A, and that high-level overexpression of this enzyme reduces the growth rate.
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Affiliation(s)
- S W Ingram
- Department of Biochemistry, University of Texas Health Science Center at San Antonio, San Antonio, TX 78229-3900, USA
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17
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Abstract
Despite being known for over 30 years, the functions of the dinucleoside polyphosphates, such as diadenosine 5',5"'-P(1), P(4)-tetraphosphate (Ap(4)A) and diadenosine 5',5"'-P(1), P(3)-triphosphate (Ap(3)A), are still unclear. On the one hand, they may have important signalling functions, both inside and outside the cell (friend), while on the other hand, they may simply be the unavoidable by-products of certain biochemical reactions, which, if allowed to accumulate, would be potentially toxic through their structural similarity to ATP and other essential mononucleotides (foe). Here, the occurrence, synthesis, degradation, and proposed functions of these compounds are briefly reviewed, along with some new data and recent evidence supporting roles for Ap(3)A and Ap(4)A in the cellular decision making processes leading to proliferation, quiescence, differentiation, and apoptosis. Hypotheses are forwarded for the involvement of Ap(4)A in the intra-S phase DNA damage checkpoint and for Ap(3)A and the pFhit (fragile histidine triad gene product) protein in tumour suppression. It is concluded that the roles of friend and foe are not incompatible, but are distinguished by the concentration range of nucleotide achieved under different circumstances.
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Affiliation(s)
- A G McLennan
- School of Biological Sciences, Life Sciences Building, University of Liverpool, Crown Street, L69 7ZB, Liverpool, UK.
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Guranowski A. Specific and nonspecific enzymes involved in the catabolism of mononucleoside and dinucleoside polyphosphates. Pharmacol Ther 2000; 87:117-39. [PMID: 11007995 DOI: 10.1016/s0163-7258(00)00046-2] [Citation(s) in RCA: 85] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
This review concerns enzymes that can degrade nucleoside 5'-tetra- and pentaphosphates (p(4)N and p(5)N) and those that can degrade various dinucleoside polyphosphates (Np(3-6)N'). Most of these enzymes are hydrolases, and they occur in all types of organisms. Certain fungi and protozoa also possess specific Np(n)N' phosphorylases. Specific p(4)N hydrolases have been demonstrated in mammals and in plants. In yeast, p(4)N and p(5)N are hydrolyzed by exopolyphosphatases. Among other hydrolases that can degrade these minor mononucleotides are phosphatases, apyrase, and (asymmetrical) Np(4)N' hydrolase, as well as the nonspecific adenylate deaminase. Np(n)N's are good substrates for Type I phosphodiesterases and nucleotide pyrophosphatases, and diadenosine polyphosphates are easily deaminated to diinosine polyphosphates by nonspecific adenylate deaminases. Specific Np(3)N' hydrolases occur in both prokaryotes and eukaryotes. Interestingly, the human fragile histidine triad (Fhit) tumor suppressor protein appears to be a typical Np(3)N' hydrolase. Among the specific Np(4)N' hydrolases are asymmetrically cleaving ones, which are typical of higher eukaryotes, and symmetrically cleaving enzymes found in Physarum polycephalum and in many bacteria. An enzyme that hydrolyzes both diadenosine tetraphosphate and diadenosine triphosphate has been found in the fission yeast Schizosaccharomyces pombe. Its amino acid sequence is similar to that of the human Fhit/Np(3)N' hydrolase. Very recently, a typical (asymmetrical) Np(4)N' hydrolase has been demonstrated for the first time in a bacterium-the pathogenic Bartonella bacilliformis. Another novelty is the discovery of diadenosine 5', 5"'-P(1),P 6-hexaphosphate hydrolases in budding and fission yeasts and in mammalian cells. These enzymes and the (asymmetrical) Np(4)N' hydrolases have the amino acid motif typical of the MutT (or Nudix hydrolase) family. In contrast, the Schizosaccharomyces pombe Ap(4)A/Ap(3)A hydrolase, the human Fhit protein, and the yeast Np(n)N' phosphorylases belong to a superfamily GAFH, which includes the histidine triad proteins.
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Affiliation(s)
- A Guranowski
- Katedra Biochemii i Biotechnologii, Akademia Rolnicza, ul. Wo>/=yOska 35, 60-637, PoznaO, Poland.
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19
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Abstract
Histidine triad (HIT) proteins were until recently a superfamily of proteins that shared only sequence motifs. Crystal structures of nucleotide-bound forms of histidine triad nucleotide-binding protein (Hint) demonstrated that the conserved residues in HIT proteins are responsible for their distinctive, dimeric, 10-stranded half-barrel structures that form two identical purine nucleotide-binding sites. Hint-related proteins, found in all forms of life, and fragile histidine triad (Fhit)-related proteins, found in animals and fungi, represent the two main branches of the HIT superfamily. Hint homologs are intracellular receptors for purine mononucleotides whose cellular function remains elusive. Fhit homologs bind and cleave diadenosine polyphosphates (Ap(n)A) such as ApppA and AppppA. Fhit-Ap(n)A complexes appear to function in a proapoptotic tumor suppression pathway in epithelial tissues. In invertebrates, Fhit homologs are encoded as fusion proteins with proteins related to plant and bacterial nitrilases that are candidate signaling partners in tumor suppression.
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Affiliation(s)
- C Brenner
- Kimmel Cancer Institute, Thomas Jefferson University, Philadelphia, Pennsylvania, USA
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