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Wu T, Xia J, Ge F, Qiu H, Tian L, Liu X, Liu R, Jiang A, Zhu J, Shi L, Yu H, Zhao M, Ren A. Target of Rapamycin Mediated Ornithine Decarboxylase Antizyme Modulate Intracellular Putrescine and Ganoderic Acid Content in Ganoderma lucidum. Microbiol Spectr 2022; 10:e0163322. [PMID: 36125287 PMCID: PMC9604110 DOI: 10.1128/spectrum.01633-22] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2022] [Accepted: 09/02/2022] [Indexed: 12/31/2022] Open
Abstract
Putrescine (Put) has been shown to play an important regulatory role in cell growth in organisms. As the primary center regulating the homeostasis of polyamine (PA) content, ornithine decarboxylase antizyme (AZ) can regulate PA content through feedback. Nevertheless, the regulatory mechanism of Put is poorly understood in fungi. Here, our analysis showed that GlAZ had a modulate effect on intracellular Put content by interacting with ornithine decarboxylase (ODC) proteins and reducing its intracellular protein levels. In addition, GlAZ upregulated the metabolic pathway of ganoderic acid (GA) biosynthesis in Ganoderma lucidum by modulating the intracellular Put content. However, a target of rapamycin (TOR) was found to promote the accumulation of intracellular Put after the GlTOR inhibitor Rap was added exogenously, and unbiased analyses demonstrated that GlTOR may promote Put production through its inhibitory effect on the level of GlAZ protein in GlTOR-GlAZ-cosilenced strains. The effect of TOR on fungal secondary metabolism was further explored, and the content of GA in the GlTOR-silenced strain after the exogenous addition of the inhibitor Rap was significantly increased compared with that in the untreated wild-type (WT) strain. Silencing of TOR in the GlTOR-silenced strains caused an increase in GA content, which returned to the WT state after replenishing Put. Moreover, the content of GA in GlTOR-GlAZ-cosilenced strains was also not different from that in the WT strain. Consequently, these results strongly indicate that GlTOR affects G. lucidum GA biosynthesis via GlAZ. IMPORTANCE Research on antizyme (AZ) in fungi has focused on the mechanism by which AZ inhibits ornithine decarboxylase (ODC). Moreover, there are existing reports on the regulation of AZ protein translation by TOR. However, little is known about the mechanisms that influence AZ in fungal secondary metabolism. Here, both intracellular Put content and GA biosynthesis in G. lucidum were shown to be regulated through protein interactions between GlAZ and GlODC. Furthermore, exploration of upstream regulators of GlAZ suggested that GlAZ was regulated by the upstream protein GlTOR, which affected intracellular Put levels and ganoderic acid (GA) biosynthesis. The results of our work contribute to the understanding of the upstream regulation of Put and provide new insights into PA regulatory systems and secondary metabolism in fungi.
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Affiliation(s)
- Tao Wu
- Key Laboratory of Microbiology for Agricultural Environment, Ministry of Agriculture, Department of Microbiology, College of Life Sciences, Nanjing Agricultural University, Jiangsu, People’s Republic of China
- Sanya Institute of Nanjing Agricultural University, Hainan, People’s Republic of China
| | - Jiale Xia
- Key Laboratory of Microbiology for Agricultural Environment, Ministry of Agriculture, Department of Microbiology, College of Life Sciences, Nanjing Agricultural University, Jiangsu, People’s Republic of China
| | - Feng Ge
- Key Laboratory of Microbiology for Agricultural Environment, Ministry of Agriculture, Department of Microbiology, College of Life Sciences, Nanjing Agricultural University, Jiangsu, People’s Republic of China
| | - Hao Qiu
- Key Laboratory of Microbiology for Agricultural Environment, Ministry of Agriculture, Department of Microbiology, College of Life Sciences, Nanjing Agricultural University, Jiangsu, People’s Republic of China
| | - Li Tian
- Key Laboratory of Microbiology for Agricultural Environment, Ministry of Agriculture, Department of Microbiology, College of Life Sciences, Nanjing Agricultural University, Jiangsu, People’s Republic of China
| | - Xiaotian Liu
- Key Laboratory of Microbiology for Agricultural Environment, Ministry of Agriculture, Department of Microbiology, College of Life Sciences, Nanjing Agricultural University, Jiangsu, People’s Republic of China
| | - Rui Liu
- Key Laboratory of Microbiology for Agricultural Environment, Ministry of Agriculture, Department of Microbiology, College of Life Sciences, Nanjing Agricultural University, Jiangsu, People’s Republic of China
| | - Ailiang Jiang
- Key Laboratory of Microbiology for Agricultural Environment, Ministry of Agriculture, Department of Microbiology, College of Life Sciences, Nanjing Agricultural University, Jiangsu, People’s Republic of China
| | - Jing Zhu
- Key Laboratory of Microbiology for Agricultural Environment, Ministry of Agriculture, Department of Microbiology, College of Life Sciences, Nanjing Agricultural University, Jiangsu, People’s Republic of China
| | - Liang Shi
- Key Laboratory of Microbiology for Agricultural Environment, Ministry of Agriculture, Department of Microbiology, College of Life Sciences, Nanjing Agricultural University, Jiangsu, People’s Republic of China
| | - Hanshou Yu
- Key Laboratory of Microbiology for Agricultural Environment, Ministry of Agriculture, Department of Microbiology, College of Life Sciences, Nanjing Agricultural University, Jiangsu, People’s Republic of China
| | - Mingwen Zhao
- Key Laboratory of Microbiology for Agricultural Environment, Ministry of Agriculture, Department of Microbiology, College of Life Sciences, Nanjing Agricultural University, Jiangsu, People’s Republic of China
| | - Ang Ren
- Key Laboratory of Microbiology for Agricultural Environment, Ministry of Agriculture, Department of Microbiology, College of Life Sciences, Nanjing Agricultural University, Jiangsu, People’s Republic of China
- Sanya Institute of Nanjing Agricultural University, Hainan, People’s Republic of China
- Institute of Biology, Guizhou Academy of Sciences, Guizhou, People’s Republic of China
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2
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Dörner K, Badertscher L, Horváth B, Hollandi R, Molnár C, Fuhrer T, Meier R, Sárazová M, van den Heuvel J, Zamboni N, Horvath P, Kutay U. Genome-wide RNAi screen identifies novel players in human 60S subunit biogenesis including key enzymes of polyamine metabolism. Nucleic Acids Res 2022; 50:2872-2888. [PMID: 35150276 PMCID: PMC8934630 DOI: 10.1093/nar/gkac072] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2021] [Revised: 01/18/2022] [Accepted: 01/25/2022] [Indexed: 12/19/2022] Open
Abstract
Ribosome assembly is an essential process that is linked to human congenital diseases and tumorigenesis. While great progress has been made in deciphering mechanisms governing ribosome biogenesis in eukaryotes, an inventory of factors that support ribosome synthesis in human cells is still missing, in particular regarding the maturation of the large 60S subunit. Here, we performed a genome-wide RNAi screen using an imaging-based, single cell assay to unravel the cellular machinery promoting 60S subunit assembly in human cells. Our screen identified a group of 310 high confidence factors. These highlight the conservation of the process across eukaryotes and reveal the intricate connectivity of 60S subunit maturation with other key cellular processes, including splicing, translation, protein degradation, chromatin organization and transcription. Intriguingly, we also identified a cluster of hits comprising metabolic enzymes of the polyamine synthesis pathway. We demonstrate that polyamines, which have long been used as buffer additives to support ribosome assembly in vitro, are required for 60S maturation in living cells. Perturbation of polyamine metabolism results in early defects in 60S but not 40S subunit maturation. Collectively, our data reveal a novel function for polyamines in living cells and provide a rich source for future studies on ribosome synthesis.
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Affiliation(s)
- Kerstin Dörner
- Institute of Biochemistry, Department of Biology, ETH Zurich, 8093 Zurich, Switzerland
- Molecular Life Sciences Ph.D. Program, 8057 Zurich, Switzerland
| | - Lukas Badertscher
- Institute of Biochemistry, Department of Biology, ETH Zurich, 8093 Zurich, Switzerland
- Molecular Life Sciences Ph.D. Program, 8057 Zurich, Switzerland
| | - Bianka Horváth
- Institute of Biochemistry, Department of Biology, ETH Zurich, 8093 Zurich, Switzerland
- Molecular Life Sciences Ph.D. Program, 8057 Zurich, Switzerland
| | - Réka Hollandi
- Synthetic and Systems Biology Unit, Biological Research Center, 6726 Szeged, Hungary
| | - Csaba Molnár
- Synthetic and Systems Biology Unit, Biological Research Center, 6726 Szeged, Hungary
| | - Tobias Fuhrer
- Institute of Molecular Systems Biology, Department of Biology, ETH Zürich, 8093 Zürich, Switzerland
| | - Roger Meier
- ScopeM, ETH Zürich, 8093 Zürich, Switzerland
| | - Marie Sárazová
- Institute of Biochemistry, Department of Biology, ETH Zurich, 8093 Zurich, Switzerland
| | - Jasmin van den Heuvel
- Institute of Biochemistry, Department of Biology, ETH Zurich, 8093 Zurich, Switzerland
| | - Nicola Zamboni
- Institute of Molecular Systems Biology, Department of Biology, ETH Zürich, 8093 Zürich, Switzerland
| | - Peter Horvath
- Synthetic and Systems Biology Unit, Biological Research Center, 6726 Szeged, Hungary
- Institute for Molecular Medicine Finland, University of Helsinki, 00014 Helsinki, Finland
| | - Ulrike Kutay
- Institute of Biochemistry, Department of Biology, ETH Zurich, 8093 Zurich, Switzerland
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Rao JN, Xiao L, Wang JY. Polyamines in Gut Epithelial Renewal and Barrier Function. Physiology (Bethesda) 2021; 35:328-337. [PMID: 32783609 DOI: 10.1152/physiol.00011.2020] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Polyamines regulate a variety of physiological functions and are involved in pathogenesis of diverse human diseases. The epithelium of the mammalian gut mucosa is a rapidly self-renewing tissue in the body, and its homeostasis is preserved through well-controlled mechanisms. Here, we highlight the roles of cellular polyamines in maintaining the integrity of the gut epithelium, focusing on the emerging evidence of polyamines in the regulation of gut epithelial renewal and barrier function. Gut mucosal growth depends on the available supply of polyamines to the dividing cells in the crypts, and polyamines are also essential for normal gut epithelial barrier function. Polyamines modulate expression of various genes encoding growth-associated proteins and intercellular junctions via distinct mechanisms involving RNA-binding proteins and noncoding RNAs. With the rapid advance of polyamine biology, polyamine metabolism and transport are promising therapeutic targets in our efforts to protect the gut epithelium and barrier function in patients with critical illnesses.
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Affiliation(s)
- Jaladanki N Rao
- Department of Surgery,Cell Biology Group, University of Maryland School of Medicine, Baltimore, Maryland.,Baltimore Veterans Affairs Medical Center, Baltimore, Maryland
| | - Lan Xiao
- Department of Surgery,Cell Biology Group, University of Maryland School of Medicine, Baltimore, Maryland.,Baltimore Veterans Affairs Medical Center, Baltimore, Maryland
| | - Jian-Ying Wang
- Department of Surgery,Cell Biology Group, University of Maryland School of Medicine, Baltimore, Maryland.,Baltimore Veterans Affairs Medical Center, Baltimore, Maryland.,Department of Pathology, University of Maryland School of Medicine, Baltimore, Maryland
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Protein degradation, the main hub in the regulation of cellular polyamines. Biochem J 2017; 473:4551-4558. [PMID: 27941031 DOI: 10.1042/bcj20160519c] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2016] [Revised: 09/20/2016] [Accepted: 09/22/2016] [Indexed: 12/15/2022]
Abstract
Ornithine decarboxylase (ODC) is the first and rate-limiting enzyme in the biosynthesis of polyamines, low-molecular-mass aliphatic polycations that are ubiquitously present in all living cells and are essential for fundamental cellular processes. Most cellular polyamines are bound, whereas the free pools, which regulate cellular functions, are subjected to tight regulation. The regulation of the free polyamine pools is manifested by modulation of their synthesis, catabolism, uptake and excretion. A central element that enables this regulation is the rapid degradation of key enzymes and regulators of these processes, particularly that of ODC. ODC degradation is part of an autoregulatory circuit that responds to the intracellular level of the free polyamines. The driving force of this regulatory circuit is a protein termed antizyme (Az). Az stimulates the degradation of ODC and inhibits polyamine uptake. Az acts as a sensor of the free intracellular polyamine pools as it is expressed via a polyamine-stimulated ribosomal frameshifting. Az binds to monomeric ODC subunits to prevent their reassociation into active homodimers and facilitates their ubiquitin-independent degradation by the 26S proteasome. In addition, through a yet unidentified mechanism, Az inhibits polyamine uptake. Interestingly, a protein, termed antizyme inhibitor (AzI) that is highly homologous with ODC, but retains no ornithine decarboxylating activity, seems to regulate cellular polyamines through its ability to negate Az. Overall, the degradation of ODC is a net result of interactions with regulatory proteins and possession of signals that mediate its ubiquitin-independent recognition by the proteasome.
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Kang B, Jiang D, Ma R, He H, Yi Z, Chen Z. OAZ1 knockdown enhances viability and inhibits ER and LHR transcriptions of granulosa cells in geese. PLoS One 2017; 12:e0175016. [PMID: 28362829 PMCID: PMC5376318 DOI: 10.1371/journal.pone.0175016] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2016] [Accepted: 03/20/2017] [Indexed: 11/18/2022] Open
Abstract
An increasing number of studies suggest that ornithine decarboxylase antizyme 1 (OAZ1), which is regarded as a tumor suppressor gene, regulates follicular development, ovulation, and steroidogenesis. The granulosa cells in the ovary play a critical role in these ovarian functions. However, the action of OAZ1 mediating physiological functions of granulosa cells is obscure. OAZ1 knockdown in granulosa cells of geese was carried out in the current study. The effect of OAZ1 knockdown on polyamine metabolism, cell proliferation, apoptosis, and hormone receptor transcription of primary granulosa cells in geese was measured. The viability of granulosa cells transfected with the shRNA OAZ1 at 48 h was significantly higher than the control (p<0.05). The level of putrescine and spermidine in granulosa cells down-regulating OAZ1 was 7.04- and 2.11- fold higher compared with the control, respectively (p<0.05). The CCND1, SMAD1, and BCL-2 mRNA expression levels in granulosa cells down-regulating OAZ1 were each significantly higher than the control, respectively (p<0.05), whereas the PCNA and CASPASE 3 expression levels were significantly lower than the control (p<0.05). The estradiol concentration, ER and LHR mRNA expression levels were significantly lower in granulosa cells down-regulating OAZ1 compared with the control (p<0.05). Taken together, our results indicated that OAZ1 knockdown elevated the putrescine and spermidine contents and enhanced granulosa cell viability and inhibited ER and LHR transcriptions of granulosa cells in geese.
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Affiliation(s)
- Bo Kang
- College of Animal Science and Technology, Sichuan Agricultural University, Chengdu, Sichuan Province, People’s Republic of China
- Farm Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province, Sichuan Agricultural University, Chengdu, Sichuan Province, People’s Republic of China
- * E-mail: (BK); (DMJ)
| | - Dongmei Jiang
- College of Animal Science and Technology, Sichuan Agricultural University, Chengdu, Sichuan Province, People’s Republic of China
- Farm Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province, Sichuan Agricultural University, Chengdu, Sichuan Province, People’s Republic of China
- * E-mail: (BK); (DMJ)
| | - Rong Ma
- College of Animal Science and Technology, Sichuan Agricultural University, Chengdu, Sichuan Province, People’s Republic of China
| | - Hui He
- College of Animal Science and Technology, Sichuan Agricultural University, Chengdu, Sichuan Province, People’s Republic of China
| | - Zhixin Yi
- College of Animal Science and Technology, Sichuan Agricultural University, Chengdu, Sichuan Province, People’s Republic of China
| | - Ziyu Chen
- College of Animal Science and Technology, Sichuan Agricultural University, Chengdu, Sichuan Province, People’s Republic of China
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6
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Effect of Oaz1 overexpression on goose ovarian granulosa cells. Amino Acids 2017; 49:1123-1132. [DOI: 10.1007/s00726-017-2411-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2016] [Accepted: 03/09/2017] [Indexed: 12/13/2022]
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7
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Hamon L, Savarin P, Pastré D. Polyamine signal through gap junctions: A key regulator of proliferation and gap-junction organization in mammalian tissues? Bioessays 2016; 38:498-507. [DOI: 10.1002/bies.201500195] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Affiliation(s)
- Loic Hamon
- Laboratoire Structure-Activité des Biomolécules Normales et Pathologiques; INSERM U1204 and Université Evry-Val d'Essonne; Evry France
| | - Philippe Savarin
- Centre National de Recherche Scientifique (CNRS), Equipe Spectroscopie des Biomolécules et des Milieux Biologiques (SBMB); Université Paris 13, Sorbonne Paris Cité, Laboratoire Chimie, Structures, Propriétés de Biomatériaux et d'Agents Thérapeutiques (CSPBAT), Unité Mixte de Recherche (UMR) 7244; Bobigny France
| | - David Pastré
- Laboratoire Structure-Activité des Biomolécules Normales et Pathologiques; INSERM U1204 and Université Evry-Val d'Essonne; Evry France
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8
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Li WD, Huang M, Lü WG, Chen X, Shen MH, Li XM, Wang RX, Ke CH. Involvement of Antizyme Characterized from the Small Abalone Haliotis diversicolor in Gonadal Development. PLoS One 2015; 10:e0135251. [PMID: 26313647 PMCID: PMC4551804 DOI: 10.1371/journal.pone.0135251] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2015] [Accepted: 07/20/2015] [Indexed: 12/19/2022] Open
Abstract
The small abalone Haliotis diversicolor is an economically important mollusk that is widely cultivated in Southern China. Gonad precocity may affect the aquaculture of small abalone. Polyamines, which are small cationic molecules essential for cellular proliferation, may affect gonadal development. Ornithine decarboxylase (ODC) and antizyme (AZ) are essential elements of a feedback circuit that regulates cellular polyamines. This paper presents the molecular cloning and characterization of AZ from small abalone. Sequence analysis showed that the cDNA sequence of H. diversicolor AZ (HdiODCAZ) consisted of two overlapping open reading frames (ORFs) and conformed to the +1 frameshift property of the frame. Thin Layer chromatography (TLC) analysis suggested that the expressed protein encoded by +1 ORF2 was the functional AZ that targets ODC to 26S proteasome degradation. The result demonstrated that the expression level of AZ was higher than that of ODC in the ovary of small abalone. In addition, the expression profiles of ODC and AZ at the different development stages of the ovary indicated that these two genes might be involved in the gonadal development of small abalone.
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Affiliation(s)
- Wei-Dong Li
- Hainan Academy of Ocean and Fisheries Sciences, Haikou, Hainan Province, China
| | - Min Huang
- Hainan Academy of Ocean and Fisheries Sciences, Haikou, Hainan Province, China
| | - Wen-Gang Lü
- College of Oceanography and Environmental Science, Xiamen University, Xiamen, Fujian Province, China
| | - Xiao Chen
- Guangxi Key Lab for Mangrove Conservation and Utilization, Guangxi Mangrove Research Center, Beihai, Guangxi Province, China
| | - Ming-Hui Shen
- Hainan Academy of Ocean and Fisheries Sciences, Haikou, Hainan Province, China
| | - Xiang-Min Li
- Hainan Academy of Ocean and Fisheries Sciences, Haikou, Hainan Province, China
| | - Rong-Xia Wang
- Hainan Academy of Ocean and Fisheries Sciences, Haikou, Hainan Province, China
| | - Cai-Huan Ke
- College of Oceanography and Environmental Science, Xiamen University, Xiamen, Fujian Province, China
- * E-mail:
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9
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Ray RM, Bavaria M, Johnson LR. Interaction of polyamines and mTOR signaling in the synthesis of antizyme (AZ). Cell Signal 2015; 27:1850-9. [PMID: 26093026 DOI: 10.1016/j.cellsig.2015.06.002] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2015] [Revised: 06/11/2015] [Accepted: 06/11/2015] [Indexed: 01/01/2023]
Abstract
Tissue polyamine levels are largely determined by the activity of ornithine decarboxylase (ODC, EC 4.1.17), which catalyzes the conversion of ornithine to the diamine putrescine. The activity of the enzyme is primarily regulated by a negative feedback mechanism involving ODC antizyme (AZ). Our previous studies demonstrated that AZ synthesis is stimulated by the absence of amino acids, the levels of which are sensed by the mTOR complex containing TORC1, which is stimulated by amino acids and inhibited by their absence, and TORC2 the function of which is not well defined. Polyamines, which cause a +1 ribosomal frameshift during the translation of AZ mRNA are required to increase AZ synthesis in both the presence and absence of amino acids. Amino acid starvation increases TORC2 activity. We have demonstrated that mTORC2 activity is necessary for AZ synthesis in the absence of amino acids. Tuberous sclerosis protein (TSC), a negative regulator of mTOR function regulates the activities of both the TORC1 and TORC2. TSC2 knockdown increased mTORC1 activity with concomitant inhibition of mTORC2 activity eliminating AZ induction in the absence of amino acids as well as that induced by spermidine. Thus, these results clearly demonstrate that in addition to polyamines, mTORC2 activity is necessary for AZ synthesis. Moreover, our results support a role for mTORC2 in the synthesis of a specific protein, AZ, which regulates growth of intestinal epithelial cells.
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Affiliation(s)
- Ramesh M Ray
- Department of Physiology, University of Tennessee Health Science Center, Memphis, TN 38163, USA.
| | - Mitul Bavaria
- Department of Physiology, University of Tennessee Health Science Center, Memphis, TN 38163, USA
| | - Leonard R Johnson
- Department of Physiology, University of Tennessee Health Science Center, Memphis, TN 38163, USA
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Yordanova MM, Wu C, Andreev DE, Sachs MS, Atkins JF. A Nascent Peptide Signal Responsive to Endogenous Levels of Polyamines Acts to Stimulate Regulatory Frameshifting on Antizyme mRNA. J Biol Chem 2015; 290:17863-17878. [PMID: 25998126 PMCID: PMC4505036 DOI: 10.1074/jbc.m115.647065] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2015] [Indexed: 01/06/2023] Open
Abstract
The protein antizyme is a negative regulator of cellular polyamine concentrations from yeast to mammals. Synthesis of functional antizyme requires programmed +1 ribosomal frameshifting at the 3′ end of the first of two partially overlapping ORFs. The frameshift is the sensor and effector in an autoregulatory circuit. Except for Saccharomyces cerevisiae antizyme mRNA, the frameshift site alone only supports low levels of frameshifting. The high levels usually observed depend on the presence of cis-acting stimulatory elements located 5′ and 3′ of the frameshift site. Antizyme genes from different evolutionary branches have evolved different stimulatory elements. Prior and new multiple alignments of fungal antizyme mRNA sequences from the Agaricomycetes class of Basidiomycota show a distinct pattern of conservation 5′ of the frameshift site consistent with a function at the amino acid level. As shown here when tested in Schizosaccharomyces pombe and mammalian HEK293T cells, the 5′ part of this conserved sequence acts at the nascent peptide level to stimulate the frameshifting, without involving stalling detectable by toe-printing. However, the peptide is only part of the signal. The 3′ part of the stimulator functions largely independently and acts at least mostly at the nucleotide level. When polyamine levels were varied, the stimulatory effect was seen to be especially responsive in the endogenous polyamine concentration range, and this effect may be more general. A conserved RNA secondary structure 3′ of the frameshift site has weaker stimulatory and polyamine sensitizing effects on frameshifting.
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Affiliation(s)
- Martina M Yordanova
- School of Biochemistry and Cell Biology, University College Cork, Cork, Ireland
| | - Cheng Wu
- Department of Biology, Texas A&M University, College Station, Texas 77843-3258
| | - Dmitry E Andreev
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow 119991, Russia
| | - Matthew S Sachs
- Department of Biology, Texas A&M University, College Station, Texas 77843-3258
| | - John F Atkins
- School of Biochemistry and Cell Biology, University College Cork, Cork, Ireland; Department of Human Genetics, University of Utah, Salt Lake City, Utah 84112-5330.
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