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Garg K, Kumar A, Kizhakkethil V, Kumar P, Singh S. Overlap in oncogenic and pro-inflammatory pathways associated with areca nut and nicotine exposure. CANCER PATHOGENESIS AND THERAPY 2024; 2:187-194. [PMID: 39027148 PMCID: PMC11252521 DOI: 10.1016/j.cpt.2023.09.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/24/2023] [Revised: 09/08/2023] [Accepted: 09/14/2023] [Indexed: 07/20/2024]
Abstract
Background Betel nut/areca nut/Areca catechu is one of the most commonly used psychoactive substance, and is also a major preventable cause of cancer. Unlike other psychoactive substances, such as nicotine, the mechanisms underlying addiction to areca nuts and related oncogenesis remain elusive. Recent reports suggest a possible overlap in the mechanisms of action of nicotine and areca nuts in the human body. Thus, this study aimed to investigate the interactome of human proteins associated with areca nut exposure and the intricate similarities and differences in the effects of the two psychoactive substances on humans. Methods A list of proteins associated with areca nut use was obtained from the available literature using terms from Medical Subject Headings (MeSH). Protein-protein interaction (PPI) networks and functional enrichment were analyzed. The results obtained for both psychoactive substances were compared. Results Given the limited number of common proteins (36/226, 16%) in the two sets, a substantial overlap (612/1176 nodes, 52%) was observed in the PPI networks, as well as in Gene Ontology. Areca nuts mainly affect signaling pathways through three hub proteins (alpha serine/threonine-protein kinase, tumor protein 53, and interleukin-6), which are common to both psychoactive substances, as well as two unique hub proteins (epidermal growth factor receptor and master regulator of cell cycle entry and proliferative metabolism). Areca nut-related proteins are associated with unique pathways, such as extracellular matrix organization, lipid storage, and metabolism, which are not found in nicotine-associated proteins. Conclusions Areca nuts affect regulatory mechanisms, leading to systemic toxicity and oncogenesis. Areca nuts also affect unique pathways that can be studied as potential markers of exposure, as well as targets for anticancer therapeutic agents.
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Affiliation(s)
- Krati Garg
- Department of Biochemical Engineering and Biotechnology, Indian Institute of Technology (IIT) Delhi, Delhi 110016, India
| | - Anuj Kumar
- Division of Molecular Biology, ICMR-National Institute of Cancer Prevention and Research (ICMR-NICPR), Indian Council of Medical Research, Noida, Uttar Pradesh 201301, India
| | - Vidisha Kizhakkethil
- Department of Biotechnology, Vellore Institute of Technology (VIT), Vellore, Tamil Nadu 632024, India
| | - Pramod Kumar
- Division of Molecular Biology, ICMR-National Institute of Cancer Prevention and Research (ICMR-NICPR), Indian Council of Medical Research, Noida, Uttar Pradesh 201301, India
| | - Shalini Singh
- ICMR-National Institute of Cancer Prevention & Research (ICMR-NICPR), Indian Council of Medical Research, Noida, Uttar Pradesh 201301, India
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Matera AG, Steiner RE, Mills CA, Herring LE, Garcia EL. Chaperoning the chaperones: Proteomic analysis of the SMN complex reveals conserved and etiologic connections to the proteostasis network. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.05.15.594402. [PMID: 38903116 PMCID: PMC11188114 DOI: 10.1101/2024.05.15.594402] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/22/2024]
Abstract
Molecular chaperones and co-chaperones are highly conserved cellular components that perform variety of duties related to the proper three-dimensional folding of the proteome. The web of factors that carries out this essential task is called the proteostasis network (PN). Ribonucleoproteins (RNPs) represent an underexplored area in terms of the connections they make with the PN. The Survival Motor Neuron (SMN) complex is an RNP assembly chaperone and serves as a paradigm for studying how specific small nuclear (sn)RNAs are identified and paired with their client substrate proteins. SMN protein is the eponymous component of a large complex required for the biogenesis of uridine-rich small nuclear ribonucleoproteins (U-snRNPs) and localizes to distinct membraneless organelles in both the nucleus and cytoplasm of animal cells. SMN forms the oligomeric core of this complex, and missense mutations in its YG box self-interaction domain are known to cause Spinal Muscular Atrophy (SMA). The basic framework for understanding how snRNAs are assembled into U-snRNPs is known, the pathways and mechanisms used by cells to regulate their biogenesis are poorly understood. Given the importance of these processes to normal development as well as neurodegenerative disease, we set out to identify and characterize novel SMN binding partners. Here, we carried out affinity purification mass spectrometry (AP-MS) of SMN using stable fly lines exclusively expressing either wildtype or SMA-causing missense alleles. Bioinformatic analyses of the pulldown data, along with comparisons to proximity labeling studies carried out in human cells, revealed conserved connections to at least two other major chaperone systems including heat shock folding chaperones (HSPs) and histone/nucleosome assembly chaperones. Notably, we found that heat shock cognate protein Hsc70-4 and other HspA family members preferentially interacted with SMA-causing alleles of SMN. Hsc70-4 is particularly interesting because its mRNA is aberrantly sequestered by a mutant form of TDP-43 in mouse and Drosophila ALS (Amyotrophic Lateral Sclerosis) disease models. Most important, a missense allele of Hsc70-4 (HspA8 in mammals) was recently identified as a bypass suppressor of the SMA phenotype in mice. Collectively, these findings suggest that chaperone-related dysfunction lies at the etiological root of both ALS and SMA.
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Affiliation(s)
- A. Gregory Matera
- Integrative Program for Biological and Genome Sciences, University of North Carolina, Chapel Hill NC, USA
- Departments of Biology and Genetics, University of North Carolina at Chapel Hill
- RNA Discovery and Lineberger Comprehensive Cancer Centers, University of North Carolina at Chapel Hill
| | - Rebecca E. Steiner
- Integrative Program for Biological and Genome Sciences, University of North Carolina, Chapel Hill NC, USA
| | - C. Alison Mills
- Department of Pharmacology, University of North Carolina at Chapel Hill
| | - Laura E. Herring
- Department of Pharmacology, University of North Carolina at Chapel Hill
| | - Eric L. Garcia
- Integrative Program for Biological and Genome Sciences, University of North Carolina, Chapel Hill NC, USA
- Department of Biology, University of Kentucky, Lexington KY, USA
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Kaur R, Kumar P, Kumar A. Insights on the nuclear shuttling of H2A-H2B histone chaperones. NUCLEOSIDES, NUCLEOTIDES & NUCLEIC ACIDS 2023:1-13. [PMID: 38133493 DOI: 10.1080/15257770.2023.2296616] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/11/2022] [Accepted: 12/12/2023] [Indexed: 12/23/2023]
Abstract
All cellular processes that involve the unwinding of DNA also lead to the systematic shuttling of histones. Histone shuttling across the nuclear membrane is facilitated by a class of proteins known as - histone chaperones. Histone chaperones are classified based on their binding to H3/H4 histones or H2A/H2B histones. During the shuttling process, two types of signals - NLS and NES are recognized by the nuclear transport proteins. However, this is the nuclear transport protein and the mechanism of signal recognition by the protein is still unknown. Thus, in this piece of work, the NLS and NES signals are predicted on important H2A/H2B binding histone chaperones. In addition, cellular localization and potential DNA binding regions of histone chaperones are predicted. Mapping of predicted regions on the histone chaperone's structure suggested that the critical binding regions mainly lie on the disordered region of the histone chaperones. NLS and NES are present in the N- and C-terminal of the histone chaperones. Most histone chaperones contain bipartiate NLS signals. This article sheds light on the crucial aspect that in addition of being directly engaged in nucleosome synthesis and disassembly in vivo, histone chaperone also performs various specific roles via histone binding activity.
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Affiliation(s)
- Rasanpreet Kaur
- Department of Biotechnology, Institute of Applied Sciences and Humanities, GLA University Mathura, Bharthia, Uttar Pradesh, India
| | - Pramod Kumar
- ICMR-National Institute of Cancer Prevention and Research, Indian Council for Medical Research (ICMR-NICPR), Noida, Uttar Pradesh, India
| | - Anuj Kumar
- ICMR-National Institute of Cancer Prevention and Research, Indian Council for Medical Research (ICMR-NICPR), Noida, Uttar Pradesh, India
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Zheng X, Zhao D, Jin Y, Liu Y, Liu D. Role of the NLRP3 inflammasome in gynecological disease. Biomed Pharmacother 2023; 166:115393. [PMID: 37660654 DOI: 10.1016/j.biopha.2023.115393] [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: 07/04/2023] [Revised: 08/20/2023] [Accepted: 08/26/2023] [Indexed: 09/05/2023] Open
Abstract
The NLR family pyrin domain containing 3 (NLRP3) inflammasome is involved in the innate immune system and is a three-part macromolecular complex comprising the NLRP3 protein, apoptosis-associated speck-like protein containing a CARD (ASC) and the cysteine protease pro-caspase-1. When the NLRP3 inflammasome is activated, it can produce interleukin (IL)- 1β and IL-18 and eventually lead to inflammatory cell pyroptosis. Related studies have demonstrated that the NLRP3 inflammasome can induce an immune response and is related to the occurrence and development of gynecological diseases, such as endometriosis, polycystic ovary syndrome and breast cancer. NLRP3 inflammasome inhibitors are beneficial for maintaining cellular homeostasis and tissue health and have been found effective in targeting some gynecological diseases. However, excessive inhibitor concentrations have been found to cause adverse effects. Therefore, proper control of NLRP3 inflammasome activity is critical. This paper summarizes the structure and function of the NLRP3 inflammasome and highlights the therapeutic potential of targeting it in gynecological diseases, such as endometriosis, polycystic ovary syndrome and breast cancer The application of NLRP3 inflammasome inhibitors is also discussed.
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Affiliation(s)
- Xu Zheng
- College of Acupuncture and Massage, Changchun University of Chinese Medicine, Changchun 130117, Jilin, China
| | - Dan Zhao
- College of Acupuncture and Massage, Changchun University of Chinese Medicine, Changchun 130117, Jilin, China
| | - Ye Jin
- School of Pharmacy, Changchun University of Chinese Medicine, Changchun 130117, Jilin, China.
| | - Yang Liu
- Acupuncture department,Affiliated Hospital of Changchun University of Chinese Medicine, Changchun 130117, Jilin, China.
| | - Da Liu
- School of Pharmacy, Changchun University of Chinese Medicine, Changchun 130117, Jilin, China.
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Wang M, Li J, Wang Y, Fu H, Qiu H, Li Y, Li M, Lu Y, Fu YV. Single-molecule study reveals Hmo1, not Hho1, promotes chromatin assembly in budding yeast. mBio 2023; 14:e0099323. [PMID: 37432033 PMCID: PMC10470511 DOI: 10.1128/mbio.00993-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2023] [Accepted: 05/25/2023] [Indexed: 07/12/2023] Open
Abstract
Linker histone H1 plays a crucial role in various biological processes, including nucleosome stabilization, high-order chromatin structure organization, gene expression, and epigenetic regulation in eukaryotic cells. Unlike higher eukaryotes, little about the linker histone in Saccharomyces cerevisiae is known. Hho1 and Hmo1 are two long-standing controversial histone H1 candidates in budding yeast. In this study, we directly observed at the single-molecule level that Hmo1, but not Hho1, is involved in chromatin assembly in the yeast nucleoplasmic extracts (YNPE), which can replicate the physiological condition of the yeast nucleus. The presence of Hmo1 facilitates the assembly of nucleosomes on DNA in YNPE, as revealed by single-molecule force spectroscopy. Further single-molecule analysis showed that the lysine-rich C-terminal domain (CTD) of Hmo1 is essential for the function of chromatin compaction, while the second globular domain at the C-terminus of Hho1 impairs its ability. In addition, Hmo1, but not Hho1, forms condensates with double-stranded DNA via reversible phase separation. The phosphorylation fluctuation of Hmo1 coincides with metazoan H1 during the cell cycle. Our data suggest that Hmo1, but not Hho1, possesses some functionality similar to that of linker histone in Saccharomyces cerevisiae, even though some properties of Hmo1 differ from those of a canonical linker histone H1. Our study provides clues for the linker histone H1 in budding yeast and provides insights into the evolution and diversity of histone H1 across eukaryotes. IMPORTANCE There has been a long-standing debate regarding the identity of linker histone H1 in budding yeast. To address this issue, we utilized YNPE, which accurately replicate the physiological conditions in yeast nuclei, in combination with total internal reflection fluorescence microscopy and magnetic tweezers. Our findings demonstrated that Hmo1, rather than Hho1, is responsible for chromatin assembly in budding yeast. Additionally, we found that Hmo1 shares certain characteristics with histone H1, including phase separation and phosphorylation fluctuations throughout the cell cycle. Furthermore, we discovered that the lysine-rich domain of Hho1 is buried by its second globular domain at the C-terminus, resulting in the loss of function that is similar to histone H1. Our study provides compelling evidence to suggest that Hmo1 shares linker histone H1 function in budding yeast and contributes to our understanding of the evolution of linker histone H1 across eukaryotes.
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Affiliation(s)
- Mengxue Wang
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
- College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Jinghua Li
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, China
| | - Yong Wang
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
- College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Hang Fu
- Wenzhou Institute, University of Chinese Academy of Sciences, Wenzhou, Zhejiang, China
- School of Physics, University of Chinese Academy of Sciences, Beijing, China
| | - Haoning Qiu
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
- College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Yanying Li
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
- College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Ming Li
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, China
- School of Physics, University of Chinese Academy of Sciences, Beijing, China
- Songshan Lake Materials Laboratory, Dongguan, Guangdong, China
| | - Ying Lu
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, China
- School of Physics, University of Chinese Academy of Sciences, Beijing, China
- Songshan Lake Materials Laboratory, Dongguan, Guangdong, China
| | - Yu Vincent Fu
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
- Savaid Medical School, University of Chinese Academy of Sciences, Beijing, China
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Zhang Y, Zhang Q, Zhang Y, Han J. The Role of Histone Modification in DNA Replication-Coupled Nucleosome Assembly and Cancer. Int J Mol Sci 2023; 24:ijms24054939. [PMID: 36902370 PMCID: PMC10003558 DOI: 10.3390/ijms24054939] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2022] [Revised: 01/28/2023] [Accepted: 01/29/2023] [Indexed: 03/08/2023] Open
Abstract
Histone modification regulates replication-coupled nucleosome assembly, DNA damage repair, and gene transcription. Changes or mutations in factors involved in nucleosome assembly are closely related to the development and pathogenesis of cancer and other human diseases and are essential for maintaining genomic stability and epigenetic information transmission. In this review, we discuss the role of different types of histone posttranslational modifications in DNA replication-coupled nucleosome assembly and disease. In recent years, histone modification has been found to affect the deposition of newly synthesized histones and the repair of DNA damage, further affecting the assembly process of DNA replication-coupled nucleosomes. We summarize the role of histone modification in the nucleosome assembly process. At the same time, we review the mechanism of histone modification in cancer development and briefly describe the application of histone modification small molecule inhibitors in cancer therapy.
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Poulet A, Rousselot E, Téletchéa S, Noirot C, Jacob Y, van Wolfswinkel J, Thiriet C, Duc C. The Histone Chaperone Network Is Highly Conserved in Physarum polycephalum. Int J Mol Sci 2023; 24:1051. [PMID: 36674565 PMCID: PMC9864664 DOI: 10.3390/ijms24021051] [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: 12/15/2022] [Revised: 12/30/2022] [Accepted: 01/02/2023] [Indexed: 01/07/2023] Open
Abstract
The nucleosome is composed of histones and DNA. Prior to their deposition on chromatin, histones are shielded by specialized and diverse proteins known as histone chaperones. They escort histones during their entire cellular life and ensure their proper incorporation in chromatin. Physarum polycephalum is a Mycetozoan, a clade located at the crown of the eukaryotic tree. We previously found that histones, which are highly conserved between plants and animals, are also highly conserved in Physarum. However, histone chaperones differ significantly between animal and plant kingdoms, and this thus probed us to further study the conservation of histone chaperones in Physarum and their evolution relative to animal and plants. Most of the known histone chaperones and their functional domains are conserved as well as key residues required for histone and chaperone interactions. Physarum is divergent from yeast, plants and animals, but PpHIRA, PpCABIN1 and PpSPT6 are similar in structure to plant orthologues. PpFACT is closely related to the yeast complex, and the Physarum genome encodes the animal-specific APFL chaperone. Furthermore, we performed RNA sequencing to monitor chaperone expression during the cell cycle and uncovered two distinct patterns during S-phase. In summary, our study demonstrates the conserved role of histone chaperones in handling histones in an early-branching eukaryote.
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Affiliation(s)
- Axel Poulet
- Department of Molecular, Cellular and Developmental Biology, Faculty of Arts and Sciences, Yale University, New Haven, CT 06511, USA
| | - Ellyn Rousselot
- Faculté des Sciences et Techniques, Nantes Université, CNRS, US2B, UMR 6286, 44000 Nantes, France
| | - Stéphane Téletchéa
- Faculté des Sciences et Techniques, Nantes Université, CNRS, US2B, UMR 6286, 44000 Nantes, France
| | - Céline Noirot
- INRAE, UR 875 Unité de Mathématique et Informatique Appliquées, Genotoul Bioinfo Auzeville, 31326 Castanet-Tolosan, France
| | - Yannick Jacob
- Department of Molecular, Cellular and Developmental Biology, Faculty of Arts and Sciences, Yale University, New Haven, CT 06511, USA
| | - Josien van Wolfswinkel
- Department of Molecular, Cellular and Developmental Biology, Faculty of Arts and Sciences, Yale University, New Haven, CT 06511, USA
| | - Christophe Thiriet
- Université Rennes 1, CNRS, IGDR (Institut de Génétique et Développement de Rennes)—UMR 6290, 35043 Rennes, France
| | - Céline Duc
- Faculté des Sciences et Techniques, Nantes Université, CNRS, US2B, UMR 6286, 44000 Nantes, France
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Okuda M, Tsunaka Y, Nishimura Y. Dynamic structures of intrinsically disordered proteins related to the general transcription factor TFIIH, nucleosomes, and histone chaperones. Biophys Rev 2022; 14:1449-1472. [PMID: 36659983 PMCID: PMC9842849 DOI: 10.1007/s12551-022-01014-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2022] [Accepted: 11/06/2022] [Indexed: 11/19/2022] Open
Abstract
Advances in structural analysis by cryogenic electron microscopy (cryo-EM) and X-ray crystallography have revealed the tertiary structures of various chromatin-related proteins, including transcription factors, RNA polymerases, nucleosomes, and histone chaperones; however, the dynamic structures of intrinsically disordered regions (IDRs) in these proteins remain elusive. Recent studies using nuclear magnetic resonance (NMR), together with molecular dynamics (MD) simulations, are beginning to reveal dynamic structures of the general transcription factor TFIIH complexed with target proteins including the general transcription factor TFIIE, the tumor suppressor p53, the cell cycle protein DP1, the DNA repair factors XPC and UVSSA, and three RNA polymerases, in addition to the dynamics of histone tails in nucleosomes and histone chaperones. In complexes of TFIIH, the PH domain of the p62 subunit binds to an acidic string formed by the IDR in TFIIE, p53, XPC, UVSSA, DP1, and the RPB6 subunit of three RNA polymerases by a common interaction mode, namely extended string-like binding of the IDR on the positively charged surface of the PH domain. In the nucleosome, the dynamic conformations of the N-tails of histones H2A and H2B are correlated, while the dynamic conformations of the N-tails of H3 and H4 form a histone tail network dependent on their modifications and linker DNA. The acidic IDRs of the histone chaperones of FACT and NAP1 play important roles in regulating the accessibility to histone proteins in the nucleosome.
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Affiliation(s)
- Masahiko Okuda
- Graduate School of Medical Life Science, Yokohama City University, 1-7-29 Suehiro-Cho, Tsurumi-Ku, Yokohama, 230-0045 Japan
| | - Yasuo Tsunaka
- Graduate School of Medical Life Science, Yokohama City University, 1-7-29 Suehiro-Cho, Tsurumi-Ku, Yokohama, 230-0045 Japan
| | - Yoshifumi Nishimura
- Graduate School of Medical Life Science, Yokohama City University, 1-7-29 Suehiro-Cho, Tsurumi-Ku, Yokohama, 230-0045 Japan
- Graduate School of Integrated Sciences for Life, Hiroshima University, 1-4-4 Kagamiyama, Higashi-Hiroshima, 739-8528 Japan
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Zhu X, Gao H, Qin S, Liu D, Cairns J, Gu Y, Yu J, Weinshilboum RM, Wang L. Testis- specific Y-encoded- like protein 1 and cholesterol metabolism: Regulation of CYP1B1 expression through Wnt signaling. Front Pharmacol 2022; 13:1047318. [PMID: 36518674 PMCID: PMC9742362 DOI: 10.3389/fphar.2022.1047318] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2022] [Accepted: 11/07/2022] [Indexed: 08/30/2023] Open
Abstract
The cytochromes P450 (CYPs) represent a large gene superfamily that plays an important role in the metabolism of both exogenous and endogenous compounds. We have reported that the testis-specific Y-encoded-like proteins (TSPYLs) are novel CYP gene transcriptional regulators. However, little is known of mechanism(s) by which TSPYLs regulate CYP expression or the functional consequences of that regulation. The TSPYL gene family includes six members, TSPYL1 to TSPYL6. However, TSPYL3 is a pseudogene, TSPYL5 is only known to regulates the expression of CYP19A1, and TSPYL6 is expressed exclusively in the testis. Therefore, TSPYL 1, 2 and 4 were included in the present study. To better understand how TSPYL1, 2, and 4 might influence CYP expression, we performed a series of pull-downs and mass spectrometric analyses. Panther pathway analysis of the 2272 pulled down proteins for all 3 TSPYL isoforms showed that the top five pathways were the Wnt signaling pathway, the Integrin signaling pathway, the Gonadotropin releasing hormone receptor pathway, the Angiogenesis pathway and Inflammation mediated by chemokines and cytokines. Specifically, we observed that 177 Wnt signaling pathway proteins were pulled down with the TSPYLs. Subsequent luciferase assays showed that TSPYL1 knockdown had a greater effect on the activation of Wnt signaling than did TSPYL2 or TSPYL4 knockdown. Therefore, in subsequent experiments, we focused our attention on TSPYL1. HepaRG cell qRT-PCR showed that TSPYL1 regulated the expression of CYPs involved in cholesterol-metabolism such as CYP1B1 and CYP7A1. Furthermore, TSPYL1 and β-catenin regulated CYP1B1 expression in opposite directions and TSPYL1 appeared to regulate CYP1B1 expression by blocking β-catenin binding to the TCF7L2 transcription factor on the CYP1B1 promoter. In β-catenin and TSPYL1 double knockdown cells, CYP1B1 expression and the generation of CYP1B1 downstream metabolites such as 20-HETE could be restored. Finally, we observed that TSPYL1 expression was associated with plasma cholesterol levels and BMI during previous clinical studies of obesity. In conclusion, this series of experiments has revealed a novel mechanism for regulation of the expression of cholesterol-metabolizing CYPs, particularly CYP1B1, by TSPYL1 via Wnt/β-catenin signaling, raising the possibility that TSPYL1 might represent a molecular target for influencing cholesterol homeostasis.
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Affiliation(s)
| | | | | | | | | | | | | | | | - Liewei Wang
- Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic, Rochester, MN, United States
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