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Wang Y, Tian X, Wang Z, Liu D, Zhao X, Sun X, Tu Z, Li Z, Zhao Y, Zheng S, Yao J. A novel peptide encoded by circ-SLC9A6 promotes lipid dyshomeostasis through the regulation of H4K16ac-mediated CD36 transcription in NAFLD. Clin Transl Med 2024; 14:e1801. [PMID: 39107881 PMCID: PMC11303264 DOI: 10.1002/ctm2.1801] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2024] [Revised: 07/16/2024] [Accepted: 07/26/2024] [Indexed: 08/10/2024] Open
Abstract
BACKGROUND As the leading cause of end-stage liver disease, nonalcoholic fatty liver disease (NAFLD) is mainly induced by lipid dyshomeostasis. The translation of endogenous circular RNAs (circRNAs) is closely related to the progression of various diseases, but the involvement of circRNAs in NAFLD has not been determined. METHODS Combined high-throughput circRNA profiles were used to identify circRNAs with translational potential. The underlying molecular mechanisms were investigated by RNA sequencing, pull-down/MS and site-specific mutagenesis. RESULTS In this study, we focused on circ-SLC9A6, an abnormally highly expressed circRNA in human and mouse liver tissue during NAFLD development that exacerbates metabolic dyshomeostasis in hepatocytes by encoding a novel peptide called SLC9A6-126aa in vivo and in vitro. YTHDF2-mediated degradation of m6A-modified circ-SLC9A6 was found to be essential for the regulation of SLC9A6-126aa expression. We further found that the phosphorylation of SLC9A6-126aa by AKT was crucial for its cytoplasmic localization and the maintenance of physiological homeostasis, whereas high-fat stress induced substantial translocation of unphosphorylated SLC9A6-126aa to the nucleus, resulting in a vicious cycle of lipid metabolic dysfunction. Nuclear SLC9A6-126aa promotes transcriptional activation of the target gene CD36 and enhances its occupancy of the CD36 promoter locus by regulating MOF-mediated histone H4K16 acetylation. Hepatic CD36 depletion significantly ameliorated hyperactivated MAPK signalling and lipid disturbance in SLC9A6-126aa transgenic mice. Clinically, increasing levels of SLC9A6-126aa were observed during NAFLD progression and were found to be positively correlated with the CD36 and MAPK cascades. CONCLUSION This study revealed the role of circ-SLC9A6-derived SLC9A6-126aa in the epigenetic modification-mediated regulation of lipid metabolism. Our findings may provide promising therapeutic targets for NAFLD and new insights into the pathological mechanisms of metabolic diseases. HIGHLIGHTS Under normal circumstances, driven by m6A modification, YTHDF2 directly recognizes and degrades circ-SLC9A6, thereby inhibiting the translation of SLC9A6-126aa. Additionally, AKT1 phosphorylates and inhibits the nuclear translocation of SLC9A6-126aa. In NAFLD, lipid overload leads to YTHDF2 and AKT1 deficiency, ultimately increasing the expression and nuclear import of SLC9A6-126aa. Nuclear SLC9A6-126aa binds directly to the CD36 promoter and initiates CD36 transcription, which induces lipid dyshomeostasis.
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Affiliation(s)
- Yue Wang
- Department of PharmacologyDalian Medical UniversityDalianChina
| | - Xinyao Tian
- Department of SurgeryDivision of Hepatobiliary and Pancreatic SurgeryThe Second Affiliated HospitalZhejiang University School of MedicineHangzhouChina
- Department of SurgeryDivision of Hepatobiliary and Pancreatic SurgeryThe First Affiliated HospitalZhejiang University School of MedicineHangzhouChina
| | - Zhecheng Wang
- Department of PharmacologyDalian Medical UniversityDalianChina
| | - Deshun Liu
- Department of General SurgeryThe Second Affiliated Hospital of Dalian Medical UniversityDalianChina
| | - Xuzi Zhao
- Department of General SurgeryThe Second Affiliated Hospital of Dalian Medical UniversityDalianChina
| | - Xin Sun
- Department of PharmacologyDalian Medical UniversityDalianChina
| | - Zuoyu Tu
- Department of PharmacologyDalian Medical UniversityDalianChina
| | - Zekuan Li
- Department of SurgeryDivision of Hepatobiliary and Pancreatic SurgeryThe First Affiliated HospitalZhejiang University School of MedicineHangzhouChina
| | - Yan Zhao
- Department of PharmacologyDalian Medical UniversityDalianChina
| | - Shusen Zheng
- Department of SurgeryDivision of Hepatobiliary and Pancreatic SurgeryThe First Affiliated HospitalZhejiang University School of MedicineHangzhouChina
- Department of Hepatobiliary and Pancreatic SurgeryDepartment of Liver TransplantationShulan (Hangzhou) HospitalHangzhouChina
| | - Jihong Yao
- Department of PharmacologyDalian Medical UniversityDalianChina
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Chong Qui E, Habtehyimer F, Germroth A, Grant J, Kosanovic L, Singh I, Hancock SP. Mycobacteriophage Alexphander Gene 94 Encodes an Essential dsDNA-Binding Protein during Lytic Infection. Int J Mol Sci 2024; 25:7466. [PMID: 39000573 PMCID: PMC11242194 DOI: 10.3390/ijms25137466] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2024] [Revised: 06/28/2024] [Accepted: 07/01/2024] [Indexed: 07/16/2024] Open
Abstract
Mycobacteriophages are viruses that specifically infect bacterial species within the genera Mycobacterium and Mycolicibacterium. Over 2400 mycobacteriophages have been isolated on the host Mycolicibacterium smegmatis and sequenced. This wealth of genomic data indicates that mycobacteriophage genomes are diverse, mosaic, and contain numerous (35-60%) genes for which there is no predicted function based on sequence similarity to characterized orthologs, many of which are essential to lytic growth. To fully understand the molecular aspects of mycobacteriophage-host interactions, it is paramount to investigate the function of these genes and gene products. Here we show that the temperate mycobacteriophage, Alexphander, makes stable lysogens with a frequency of 2.8%. Alexphander gene 94 is essential for lytic infection and encodes a protein predicted to contain a C-terminal MerR family helix-turn-helix DNA-binding motif (HTH) and an N-terminal DinB/YfiT motif, a putative metal-binding motif found in stress-inducible gene products. Full-length and C-terminal gp94 constructs form high-order nucleoprotein complexes on 100-500 base pair double-stranded DNA fragments and full-length phage genomic DNA with little sequence discrimination for the DNA fragments tested. Maximum gene 94 mRNA levels are observed late in the lytic growth cycle, and gene 94 is transcribed in a message with neighboring genes 92 through 96. We hypothesize that gp94 is an essential DNA-binding protein for Alexphander during lytic growth. We proposed that gp94 forms multiprotein complexes on DNA through cooperative interactions involving its HTH DNA-binding motif at sites throughout the phage chromosome, facilitating essential DNA transactions required for lytic propagation.
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Affiliation(s)
| | | | | | | | | | | | - Stephen P. Hancock
- Department of Chemistry, Towson University, Towson, MD 21252, USA; (E.C.Q.); (F.H.); (A.G.); (J.G.); (L.K.); (I.S.)
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Kim YY, Kim JC, Kim S, Yang JE, Kim HM, Park HW. Heterotypic stress-induced adaptive evolution enhances freeze-drying tolerance and storage stability of Leuconostoc mesenteroides WiKim33. Food Res Int 2024; 175:113731. [PMID: 38128991 DOI: 10.1016/j.foodres.2023.113731] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2023] [Revised: 11/15/2023] [Accepted: 11/22/2023] [Indexed: 12/23/2023]
Abstract
Lactic acid bacteria (LAB) are currently being investigated for their potential use as probiotics and starter cultures. Researchers have developed powdering processes for the commercialization of LAB. Previous studies have focused on identifying innovative cryoprotective agents and freeze-drying (FD) techniques to enhance the stability of LAB. In this study, adaptive laboratory evolution (ALE) was employed to develop a strain with high FD tolerance and enhanced storage stability. Leuconostoc mesenteroids WiKim33 was subjected to heterotypic shock (heat and osmosis shock) to induce the desired phenotype and genotype. An FD-tolerant enhanced Leu. mesenteroides WiKim33 strain (ALE50) was obtained, which harbored a modified fatty acid composition and cell envelope characteristics. Specifically, ALE50 showed a lower unsaturated fatty acid (UFA)/saturated fatty acid (SFA) ratio and a higher cyclic fatty acid (CFA) composition. Moreover, the exopolysaccharide (EPS) thickness increased significantly by 331% compared to that of the wild type (WT). FD tolerance, which was evaluated using viability testing after FD, was enhanced by 33.4%. Overall, we demonstrated the feasibility of ALE to achieve desirable characteristics and provided insights into the mechanisms underlying increased FD tolerance.
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Affiliation(s)
- Yeong Yeol Kim
- Technology Innovation Research Division, World Institute of Kimchi, Gwangju 61755, Republic of Korea; Department of Integrative Food, Bioscience and Biotechnology, Chonnam National University, Gwangju 61186, Republic of Korea
| | - Jong-Cheol Kim
- Technology Innovation Research Division, World Institute of Kimchi, Gwangju 61755, Republic of Korea
| | - Seulbi Kim
- Technology Innovation Research Division, World Institute of Kimchi, Gwangju 61755, Republic of Korea; Division of Applied Bioscience & Biotechnology, Chonnam National University, Gwangju 61186, Republic of Korea
| | - Jung Eun Yang
- Technology Innovation Research Division, World Institute of Kimchi, Gwangju 61755, Republic of Korea
| | - Ho Myeong Kim
- Technology Innovation Research Division, World Institute of Kimchi, Gwangju 61755, Republic of Korea.
| | - Hae Woong Park
- Technology Innovation Research Division, World Institute of Kimchi, Gwangju 61755, Republic of Korea.
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Heat, cold, acid, and bile salt induced differential proteomic responses of a novel potential probiotic Lactococcus garvieae C47 isolated from camel milk. Food Chem 2022; 397:133774. [PMID: 35905615 DOI: 10.1016/j.foodchem.2022.133774] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2022] [Revised: 07/20/2022] [Accepted: 07/21/2022] [Indexed: 11/21/2022]
Abstract
Probiotics encounter various stresses during food processing and digestion. This study evaluated the differential proteomic responses of a newly identified potential probiotic lactic acid bacteria, Lactococcus garvieae, isolated from camel milk. Lc. garvieae C47 was exposed to heat, cold, acid, and bile conditions, and stress-responsive proteins were identified. The proteomic analysis was done using 2D-IEF SDS PAGE and nano-LC-MS/MS. Out of 91 differentially expressed proteins, 20 upregulated and 27 downregulated proteins were shared among the stresses. The multivariate data analysis revealed abundance of elongation factor Ts (spot C42), uridine phosphorylase, fructose-bisphosphate aldolase, peptidase T, cobalt ECF transporter T component CbiQ, UDP-N-acetylmuramate-l-alanine ligase, uncharacterized protein, aspartokinase, chaperone protein DnaK, IGP synthase cyclase subunit, probable nicotinate-nucleotide adenylyltransferase, NADH-quinone oxidoreductase, holo-[acyl-carrier-protein] synthase, l-lactate dehydrogenase, and uncharacterized protein. The maximum number of differentially expressed proteins belonged to carbohydrate and protein metabolism, which indicates Lc. garvieae shifts towards growth and energy metabolism for resistance against stress conditions.
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Investigating a putative transcriptional regulatory protein encoded by Rv1719 gene of Mycobacterium tuberculosis. Protein J 2022; 41:424-433. [PMID: 35715720 DOI: 10.1007/s10930-022-10062-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/03/2022] [Indexed: 10/18/2022]
Abstract
Mycobacterium tuberculosis, the causative agent of tuberculosis, demonstrates immense plasticity with which it adapts to a highly dynamic and hostile host environment. This is facilitated by a web of signalling pathways constantly modulated by a multitude of proteins that regulate the flow of genetic information inside the pathogen. Transcription factors (TFs) belongs to one such family of proteins that modulate the signalling by regulating the abundance of proteins at the transcript level. In the current study, we have characterized the putative transcriptional regulatory protein encoded by the Rv1719 gene of Mycobacterium tuberculosis. This TF belongs to the IclR family of proteins with orthologs found in both bacterial and archaeal species. We cloned the Rv1719 gene into the pET28a expression vector and performed heterologous expression of the recombinant protein with E coli as the host. Further, optimization of the purification protocol by affinity chromatography and characterization of proteins for their functional viability has been demonstrated using various biochemical and/or biophysical approaches. Scale-up of purification yielded approximately 30 mg of ~ 28 kDa protein per litre of culture. In-silico protein domain analysis of Rv1719 protein predicted the presence of the helix-turn-helix (HTH) domain suggesting its ability to bind DNA sequence and modulate transcription; a hallmark of a transcriptional regulatory protein. Further, by performing electrophoretic mobility shift assay (EMSA) we demonstrated that the protein binds to a specific DNA fragment harboring the probable binding site of one of the predicted promoters.
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Fang C, Zhang Y. Bacterial MerR family transcription regulators: activationby distortion. Acta Biochim Biophys Sin (Shanghai) 2021; 54:25-36. [PMID: 35130613 PMCID: PMC9909328 DOI: 10.3724/abbs.2021003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
Transcription factors (TFs) modulate gene expression by regulating the accessibility of promoter DNA to RNA polymerases (RNAPs) in bacteria. The MerR family TFs are a large class of bacterial proteins unique in their physiological functions and molecular action: they function as transcription repressors under normal circumstances, but rapidly transform to transcription activators under various cellular triggers, including oxidative stress, imbalance of cellular metal ions, and antibiotic challenge. The promoters regulated by MerR TFs typically contain an abnormal long spacer between the -35 and -10 elements, where MerR TFs bind and regulate transcription activity through unique mechanisms. In this review, we summarize the function, ligand reception, DNA recognition, and molecular mechanism of transcription regulation of MerR-family TFs.
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Affiliation(s)
- Chengli Fang
- Key Laboratory of Synthetic BiologyCAS Center for Excellence in Molecular Plant SciencesShanghai Institute of Plant Physiology and EcologyChinese Academy of SciencesShanghai200032China
| | - Yu Zhang
- Key Laboratory of Synthetic BiologyCAS Center for Excellence in Molecular Plant SciencesShanghai Institute of Plant Physiology and EcologyChinese Academy of SciencesShanghai200032China
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Baig MA, Turner MS, Liu SQ, Al-Nabulsi AA, Shah NP, Ayyash MM. Potential Probiotic Pediococcus pentosaceus M41 Modulates Its Proteome Differentially for Tolerances Against Heat, Cold, Acid, and Bile Stresses. Front Microbiol 2021; 12:731410. [PMID: 34721329 PMCID: PMC8548654 DOI: 10.3389/fmicb.2021.731410] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2021] [Accepted: 09/13/2021] [Indexed: 01/01/2023] Open
Abstract
Probiotics containing functional food confer health benefits in addition to their nutritional properties. In this study, we have evaluated the differential proteomic responses of a potential novel probiotic Pediococcus pentosaceus M41 under heat, cold, acid, and bile stress conditions. We identified stress response proteins that could provide tolerances against these stresses and could be used as probiotic markers for evaluating stress tolerance. Pediococcus pentosaceus M41 was exposed for 2 h to each condition: 50°C (heat stress), 4°C (cold stress), pH 3.0 (acid stress) and 0.05% bile (bile stress). Proteomic analysis was carried out using 2D-IEF SDS PAGE and LC-MS/MS. Out of 60 identified proteins, 14 upregulated and 6 downregulated proteins were common among all the stress conditions. These proteins were involved in different biological functions such as translation-related proteins, carbohydrate metabolism (phosphoenolpyruvate phosphotransferase), histidine biosynthesis (imidazole glycerol phosphate synthase) and cell wall synthesis (tyrosine-protein kinase CapB). Proteins such as polysaccharide deacetylase, lactate oxidase, transcription repressor NrdR, dihydroxyacetone kinase were upregulated under three out of the four stress conditions. The differential expression of these proteins might be responsible for tolerance and protection of P. pentosaceus M41 against different stress conditions.
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Affiliation(s)
- Mohd Affan Baig
- Department of Food Science, College of Agriculture and Veterinary Medicine, United Arab Emirates University, Al Ain, United Arab Emirates
| | - Mark S. Turner
- School of Agriculture and Food Sciences, The University of Queensland, Brisbane, QLD, Australia
| | - Shao-Quan Liu
- Department of Food Science and Technology, Faculty of Science, National University of Singapore, Singapore, Singapore
| | - Anas A. Al-Nabulsi
- Department of Nutrition and Food Technology, Jordan University of Science and Technology, Irbid, Jordan
| | - Nagendra P. Shah
- Food and Nutritional Science, School of Biological Sciences, The University of Hong Kong, Pokfulam, Hong Kong, SAR China
| | - Mutamed M. Ayyash
- Department of Food Science, College of Agriculture and Veterinary Medicine, United Arab Emirates University, Al Ain, United Arab Emirates
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Kraxner KJ, Polen T, Baumgart M, Bott M. The conserved actinobacterial transcriptional regulator FtsR controls expression of ftsZ and further target genes and influences growth and cell division in Corynebacterium glutamicum. BMC Microbiol 2019; 19:179. [PMID: 31382874 PMCID: PMC6683498 DOI: 10.1186/s12866-019-1553-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2019] [Accepted: 07/24/2019] [Indexed: 01/11/2023] Open
Abstract
Background Key mechanisms of cell division and its regulation are well understood in model bacteria such as Escherichia coli and Bacillus subtilis. In contrast, current knowledge on the regulation of cell division in Actinobacteria is rather limited. FtsZ is one of the key players in this process, but nothing is known about its transcriptional regulation in Corynebacterium glutamicum, a model organism of the Corynebacteriales. Results In this study, we used DNA affinity chromatography to search for transcriptional regulators of ftsZ in C. glutamicum and identified the Cg1631 protein as candidate, which was named FtsR. Both deletion and overexpression of ftsR caused growth defects and an altered cell morphology. Plasmid-based expression of native ftsR or of homologs of the pathogenic relatives Corynebacterium diphtheriae and Mycobacterium tuberculosis in the ΔftsR mutant could at least partially reverse the mutant phenotype. Absence of ftsR caused decreased expression of ftsZ, in line with an activator function of FtsR. In vivo crosslinking followed by affinity purification of FtsR and next generation sequencing of the enriched DNA fragments confirmed the ftsZ promoter as in vivo binding site of FtsR and revealed additional potential target genes and a DNA-binding motif. Analysis of strains expressing ftsZ under control of the gluconate-inducible gntK promoter revealed that the phenotype of the ΔftsR mutant is not solely caused by reduced ftsZ expression, but involves further targets. Conclusions In this study, we identified and characterized FtsR as the first transcriptional regulator of FtsZ described for C. glutamicum. Both the absence and the overproduction of FtsR had severe effects on growth and cell morphology, underlining the importance of this regulatory protein. FtsR and its DNA-binding site in the promoter region of ftsZ are highly conserved in Actinobacteria, which suggests that this regulatory mechanism is also relevant for the control of cell division in related Actinobacteria. Electronic supplementary material The online version of this article (10.1186/s12866-019-1553-0) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Kim Julia Kraxner
- IBG-1: Biotechnology, Institute for Bio- und Geosciences, Forschungszentrum Jülich, 52425, Jülich, Germany
| | - Tino Polen
- IBG-1: Biotechnology, Institute for Bio- und Geosciences, Forschungszentrum Jülich, 52425, Jülich, Germany
| | - Meike Baumgart
- IBG-1: Biotechnology, Institute for Bio- und Geosciences, Forschungszentrum Jülich, 52425, Jülich, Germany.
| | - Michael Bott
- IBG-1: Biotechnology, Institute for Bio- und Geosciences, Forschungszentrum Jülich, 52425, Jülich, Germany.
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