1
|
Yang XM, Wang XQ, Hu LP, Feng MX, Zhou YQ, Li DX, Li J, Miao XC, Zhang YL, Yao LL, Nie HZ, Huang S, Xia Q, Zhang XL, Jiang SH, Zhang ZG. Nucleolar HEAT Repeat Containing 1 Up-regulated by the Mechanistic Target of Rapamycin Complex 1 Signaling Promotes Hepatocellular Carcinoma Growth by Dominating Ribosome Biogenesis and Proteome Homeostasis. Gastroenterology 2023; 165:629-646. [PMID: 37247644 DOI: 10.1053/j.gastro.2023.05.029] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/10/2022] [Revised: 04/14/2023] [Accepted: 05/12/2023] [Indexed: 05/31/2023]
Abstract
BACKGROUND & AIMS Hyperactivation of ribosome biogenesis leads to hepatocyte transformation and plays pivotal roles in hepatocellular carcinoma (HCC) development. We aimed to identify critical ribosome biogenesis proteins that are overexpressed and crucial in HCC progression. METHODS HEAT repeat containing 1 (HEATR1) expression and clinical correlations were analyzed using The Cancer Genome Atlas and Gene Expression Omnibus databases and further evaluated by immunohistochemical analysis of an HCC tissue microarray. Gene expression was knocked down by small interfering RNA. HEATR1-knockdown cells were subjected to viability, cell cycle, and apoptosis assays and used to establish subcutaneous and orthotopic tumor models. Chromatin immunoprecipitation and quantitative polymerase chain reaction were performed to detect the association of candidate proteins with specific DNA sequences. Endogenous coimmunoprecipitation combined with mass spectrometry was used to identify protein interactions. We performed immunoblot and immunofluorescence assays to detect and localize proteins in cells. The nucleolus ultrastructure was detected by transmission electron microscopy. Click-iT (Thermo Fisher Scientific) RNA imaging and puromycin incorporation assays were used to measure nascent ribosomal RNA and protein synthesis, respectively. Proteasome activity, 20S proteasome foci formation, and protein stability were evaluated in HEATR1-knockdown HCC cells. RESULTS HEATR1 was the most up-regulated gene in a set of ribosome biogenesis mediators in HCC samples. High expression of HEATR1 was associated with poor survival and malignant clinicopathologic features in patients with HCC and contributed to HCC growth in vitro and in vivo. HEATR1 expression was regulated by the transcription factor specificity protein 1, which can be activated by insulin-like growth factor 1-mammalian target of rapamycin complex 1 signaling in HCC cells. HEATR1 localized predominantly in the nucleolus, bound to ribosomal DNA, and was associated with RNA polymerase I transcription/processing factors. Knockdown of HEATR1 disrupted ribosomal RNA biogenesis and impaired nascent protein synthesis, leading to reduced cytoplasmic proteasome activity and inhibitory-κB/nuclear factor-κB signaling. Moreover, HEATR1 knockdown induced nucleolar stress with increased nuclear proteasome activity and inactivation of the nucleophosmin 1-MYC axis. CONCLUSIONS Our study revealed that HEATR1 is up-regulated by insulin-like growth factor 1-mammalian target of rapamycin complex 1-specificity protein 1 signaling in HCC and functions as a crucial regulator of ribosome biogenesis and proteome homeostasis to promote HCC development.
Collapse
Affiliation(s)
- Xiao-Mei Yang
- State Key Laboratory of Systems Medicine for Cancer, Shanghai Cancer Institute, Renji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Xiao-Qi Wang
- State Key Laboratory of Systems Medicine for Cancer, Shanghai Cancer Institute, Renji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Li-Peng Hu
- State Key Laboratory of Systems Medicine for Cancer, Shanghai Cancer Institute, Renji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Ming-Xuan Feng
- Department of Transplantation and Hepatic Surgery, Renji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Yao-Qi Zhou
- State Key Laboratory of Systems Medicine for Cancer, Shanghai Cancer Institute, Renji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Dong-Xue Li
- State Key Laboratory of Systems Medicine for Cancer, Shanghai Cancer Institute, Renji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Jun Li
- State Key Laboratory of Systems Medicine for Cancer, Shanghai Cancer Institute, Renji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Xiao-Cao Miao
- State Key Laboratory of Systems Medicine for Cancer, Shanghai Cancer Institute, Renji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Yan-Li Zhang
- State Key Laboratory of Systems Medicine for Cancer, Shanghai Cancer Institute, Renji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Lin-Li Yao
- State Key Laboratory of Systems Medicine for Cancer, Shanghai Cancer Institute, Renji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Hui-Zhen Nie
- State Key Laboratory of Systems Medicine for Cancer, Shanghai Cancer Institute, Renji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Shan Huang
- State Key Laboratory of Systems Medicine for Cancer, Shanghai Cancer Institute, Renji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Qiang Xia
- Department of Transplantation and Hepatic Surgery, Renji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Xue-Li Zhang
- State Key Laboratory of Systems Medicine for Cancer, Shanghai Cancer Institute, Renji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
| | - Shu-Heng Jiang
- State Key Laboratory of Systems Medicine for Cancer, Shanghai Cancer Institute, Renji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
| | - Zhi-Gang Zhang
- State Key Laboratory of Systems Medicine for Cancer, Shanghai Cancer Institute, Renji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
| |
Collapse
|
2
|
Iriki T, Iio H, Yasuda S, Masuta S, Kato M, Kosako H, Hirayama S, Endo A, Ohtake F, Kamiya M, Urano Y, Saeki Y, Hamazaki J, Murata S. Senescent cells form nuclear foci that contain the 26S proteasome. Cell Rep 2023; 42:112880. [PMID: 37541257 DOI: 10.1016/j.celrep.2023.112880] [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: 11/01/2022] [Revised: 05/26/2023] [Accepted: 07/13/2023] [Indexed: 08/06/2023] Open
Abstract
The proteasome plays a central role in intracellular protein degradation. Age-dependent decline in proteasome activity is associated with cellular senescence and organismal aging; however, the mechanism by which the proteasome plays a role in senescent cells remains elusive. Here, we show that nuclear foci that contain the proteasome and exhibit liquid-like properties are formed in senescent cells. The formation of senescence-associated nuclear proteasome foci (SANPs) is dependent on ubiquitination and RAD23B, similar to previously known nuclear proteasome foci, but also requires proteasome activity. RAD23B knockdown suppresses SANP formation and increases mitochondrial activity, leading to reactive oxygen species production without affecting other senescence traits such as cell-cycle arrest and cell morphology. These findings suggest that SANPs are an important feature of senescent cells and uncover a mechanism by which the proteasome plays a role in senescent cells.
Collapse
Affiliation(s)
- Tomohiro Iriki
- Laboratory of Protein Metabolism, Graduate School of Pharmaceutical Sciences, the University of Tokyo, Bunkyo-ku, Tokyo 1130033, Japan
| | - Hiroaki Iio
- Laboratory of Protein Metabolism, Graduate School of Pharmaceutical Sciences, the University of Tokyo, Bunkyo-ku, Tokyo 1130033, Japan
| | - Shu Yasuda
- Department of Hygienic Chemistry and Medical Research Laboratories, School of Pharmaceutical Sciences, Kitasato University, Minato-ku, Tokyo 1088641, Japan
| | - Shun Masuta
- Laboratory of Protein Metabolism, Graduate School of Pharmaceutical Sciences, the University of Tokyo, Bunkyo-ku, Tokyo 1130033, Japan
| | - Masakazu Kato
- Faculty of Pharmaceutical Sciences, Teikyo Heisei University, Nakano-ku, Tokyo 1648530, Japan
| | - Hidetaka Kosako
- Division of Cell Signaling, Fujii Memorial Institute of Medical Sciences, Tokushima University, Kuramoto-cho, Tokushima 7708503, Japan
| | - Shoshiro Hirayama
- Laboratory of Protein Metabolism, Graduate School of Pharmaceutical Sciences, the University of Tokyo, Bunkyo-ku, Tokyo 1130033, Japan
| | - Akinori Endo
- Laboratory of Protein Metabolism, Tokyo Metropolitan Institute of Medical Science, Setagaya-ku, Tokyo 1568506, Japan
| | - Fumiaki Ohtake
- Institute for Advanced Life Sciences, Hoshi University, Shinagawa-ku, Tokyo 1428501, Japan
| | - Mako Kamiya
- Department of Life Science and Technology, Tokyo Institute of Technology, Midori-ku, Yokohama 2268501, Japan
| | - Yasuteru Urano
- Laboratory of Chemical Biology and Molecular Imaging, Graduate School of Medicine, the University of Tokyo, Bunkyo-ku, Tokyo 1130033, Japan; Laboratory of Chemical Biology and Molecular Imaging, Graduate School of Pharmaceutical Sciences, the University of Tokyo, Bunkyo-ku, Tokyo 1130033, Japan
| | - Yasushi Saeki
- Division of Protein Metabolism, the Institute of Medical Science, the University of Tokyo, Minato-ku, Tokyo 1088639, Japan
| | - Jun Hamazaki
- Laboratory of Protein Metabolism, Graduate School of Pharmaceutical Sciences, the University of Tokyo, Bunkyo-ku, Tokyo 1130033, Japan
| | - Shigeo Murata
- Laboratory of Protein Metabolism, Graduate School of Pharmaceutical Sciences, the University of Tokyo, Bunkyo-ku, Tokyo 1130033, Japan.
| |
Collapse
|
3
|
Fernando LM, Quesada-Candela C, Murray M, Ugoaru C, Yanowitz JL, Allen AK. Proteasomal subunit depletions differentially affect germline integrity in C. elegans. Front Cell Dev Biol 2022; 10:901320. [PMID: 36060813 PMCID: PMC9428126 DOI: 10.3389/fcell.2022.901320] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2022] [Accepted: 07/08/2022] [Indexed: 11/25/2022] Open
Abstract
The 26S proteasome is a multi-subunit protein complex that is canonically known for its ability to degrade proteins in cells and maintain protein homeostasis. Non-canonical or non-proteolytic roles of proteasomal subunits exist but remain less well studied. We provide characterization of germline-specific functions of different 19S proteasome regulatory particle (RP) subunits in C. elegans using RNAi specifically from the L4 stage and through generation of endogenously tagged 19S RP lid subunit strains. We show functions for the 19S RP in regulation of proliferation and maintenance of integrity of mitotic zone nuclei, in polymerization of the synaptonemal complex (SC) onto meiotic chromosomes and in the timing of SC subunit redistribution to the short arm of the bivalent, and in turnover of XND-1 proteins at late pachytene. Furthermore, we report that certain 19S RP subunits are required for proper germ line localization of WEE-1.3, a major meiotic kinase. Additionally, endogenous fluorescent labeling revealed that the two isoforms of the essential 19S RP proteasome subunit RPN-6.1 are expressed in a tissue-specific manner in the hermaphrodite. Also, we demonstrate that the 19S RP subunits RPN-6.1 and RPN-7 are crucial for the nuclear localization of the lid subunits RPN-8 and RPN-9 in oocytes, further supporting the ability to utilize the C. elegans germ line as a model to study proteasome assembly real-time. Collectively, our data support the premise that certain 19S RP proteasome subunits are playing tissue-specific roles, especially in the germ line. We propose C. elegans as a versatile multicellular model to study the diverse proteolytic and non-proteolytic roles that proteasome subunits play in vivo.
Collapse
Affiliation(s)
| | - Cristina Quesada-Candela
- Magee-Womens Research Institute and Department of Obstetrics, Gynecology, and Reproductive Sciences, University of Pittsburgh School of Medicine, Pittsburgh, PA, United States
| | - Makaelah Murray
- Department of Biology, Howard University, Washington, DC, United States
| | - Caroline Ugoaru
- Department of Biology, Howard University, Washington, DC, United States
| | - Judith L. Yanowitz
- Magee-Womens Research Institute and Department of Obstetrics, Gynecology, and Reproductive Sciences, University of Pittsburgh School of Medicine, Pittsburgh, PA, United States
- Departments of Developmental Biology, Microbiology, and Molecular Genetics, The Hillman Cancer Center, University of Pittsburgh School of Medicine, Pittsburgh, PA, United States
- *Correspondence: Judith L. Yanowitz, ; Anna K. Allen,
| | - Anna K. Allen
- Department of Biology, Howard University, Washington, DC, United States
- *Correspondence: Judith L. Yanowitz, ; Anna K. Allen,
| |
Collapse
|
4
|
Wright EB, Lannigan DA. ERK1/2‐RSK regulation of oestrogen homeostasis. FEBS J 2022; 290:1943-1953. [PMID: 35176205 PMCID: PMC9381647 DOI: 10.1111/febs.16407] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2021] [Revised: 12/23/2021] [Accepted: 02/15/2022] [Indexed: 11/28/2022]
Abstract
The molecular mechanisms regulating oestrogen homeostasis have been primarily studied in the mammary gland, which is the focus of this review. In the non-pregnant adult, the mammary gland undergoes repeated cycles of proliferation and apoptosis in response to the fluctuating levels of oestrogen that occur during the reproductive stage. Oestrogen actions are mediated through the steroid hormone receptors, oestrogen receptor α and β and through a G-protein coupled receptor. In the mammary gland, ERα is of particular importance and thus will be highlighted. Mechanisms regulating oestrogen-induced responses through ERα are necessary to maintain homeostasis given that the signalling pathways that are activated in response to ERα-mediated transcription can also induce transformation. ERK1/2 and its downstream effector, p90 ribosomal S6 kinase (RSK), control homeostasis in the mammary gland by limiting oestrogen-mediated ERα responsiveness. ERK1/2 drives degradation coupled ERα-mediated transcription, whereas RSK2 acts as a negative regulator of ERK1/2 activity to limit oestrogen responsiveness. Moreover, RSK2 acts as a positive regulator of translation. Thus, RSK2 provides both positive and negative signals to maintain oestrogen responsiveness. In addition to transmitting signals through tyrosine kinase receptors, ERK1/2-RSK engages with hedgehog signalling to maintain oestrogen levels and with the HIPPO pathway to regulate ERα-mediated transcription. Additionally, ERK1/2-RSK controls the progenitor populations within the mammary gland to maintain the ERα-positive population. RSK2 is involved in increased breast cancer risk in individuals taking oral contraceptives and in parity-induced protection against breast cancer. RSK2 and ERα may also co-operate in diseases in tissues outside of the mammary gland.
Collapse
Affiliation(s)
- Eric B. Wright
- Biomedical Engineering Vanderbilt University Nashville TN USA
| | - Deborah A. Lannigan
- Biomedical Engineering Vanderbilt University Nashville TN USA
- Pathology, Microbiology & Immunology Vanderbilt University Medical Center Nashville TN USA
- Cell and Developmental Biology Vanderbilt University Nashville TN USA
| |
Collapse
|
5
|
Moree SE, Maneix L, Iakova P, Stossi F, Sahin E, Catic A. Imaging-Based Screening of Deubiquitinating Proteases Identifies Otubain-1 as a Stabilizer of c-MYC. Cancers (Basel) 2022; 14:806. [PMID: 35159073 PMCID: PMC8833929 DOI: 10.3390/cancers14030806] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2021] [Revised: 02/01/2022] [Accepted: 02/02/2022] [Indexed: 02/01/2023] Open
Abstract
The ubiquitin-proteasome pathway precisely controls the turnover of transcription factors in the nucleus, playing an important role in maintaining appropriate quantities of these regulatory proteins. The transcription factor c-MYC is essential for normal development and is a critical cancer driver. Despite being highly expressed in several tissues and malignancies, the c-MYC protein is also continuously targeted by the ubiquitin-proteasome pathway, which can either facilitate or inhibit c-MYC degradation. Deubiquitinating proteases can remove ubiquitin chains from target proteins and rescue them from proteasomal digestion. This study sought to determine novel elements of the ubiquitin-proteasome pathway that regulate c-MYC levels. We performed an overexpression screen with 41 human proteases to identify which deubiquitinases stabilize c-MYC. We discovered that the highly expressed Otubain-1 (OTUB1) protease increases c-MYC protein levels. Confirming its role in enhancing c-MYC activity, we found that elevated OTUB1 correlates with inferior clinical outcomes in the c-MYC-dependent cancer multiple myeloma, and overexpression of OTUB1 accelerates the growth of myeloma cells. In summary, our study identifies OTUB1 as a novel amplifier of the proto-oncogene c-MYC.
Collapse
Affiliation(s)
- Shannon E. Moree
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX 77030, USA; (S.E.M.); (L.M.); (P.I.); (F.S.)
- Huffington Center on Aging, Baylor College of Medicine, Houston, TX 77030, USA;
- Stem Cells and Regenerative Medicine Center, Baylor College of Medicine, Houston, TX 77030, USA
| | - Laure Maneix
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX 77030, USA; (S.E.M.); (L.M.); (P.I.); (F.S.)
- Huffington Center on Aging, Baylor College of Medicine, Houston, TX 77030, USA;
- Stem Cells and Regenerative Medicine Center, Baylor College of Medicine, Houston, TX 77030, USA
| | - Polina Iakova
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX 77030, USA; (S.E.M.); (L.M.); (P.I.); (F.S.)
- Huffington Center on Aging, Baylor College of Medicine, Houston, TX 77030, USA;
- Stem Cells and Regenerative Medicine Center, Baylor College of Medicine, Houston, TX 77030, USA
| | - Fabio Stossi
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX 77030, USA; (S.E.M.); (L.M.); (P.I.); (F.S.)
- Gulf Coast Consortia, Center for Advanced Microscopy and Image Informatics, Houston, TX 77030, USA
| | - Ergun Sahin
- Huffington Center on Aging, Baylor College of Medicine, Houston, TX 77030, USA;
| | - Andre Catic
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX 77030, USA; (S.E.M.); (L.M.); (P.I.); (F.S.)
- Huffington Center on Aging, Baylor College of Medicine, Houston, TX 77030, USA;
- Stem Cells and Regenerative Medicine Center, Baylor College of Medicine, Houston, TX 77030, USA
- Dan L. Duncan Comprehensive Cancer Center, Baylor College of Medicine, Houston, TX 77030, USA
- Center for Cell and Gene Therapy, Baylor College of Medicine, Houston, TX 77030, USA
- Michael E. DeBakey VA Medical Center, Houston, TX 77030, USA
| |
Collapse
|
6
|
The Ketogenic Diet Reduces the Harmful Effects of Stress on Gut Mitochondrial Biogenesis in a Rat Model of Irritable Bowel Syndrome. Int J Mol Sci 2021; 22:ijms22073498. [PMID: 33800646 PMCID: PMC8037144 DOI: 10.3390/ijms22073498] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2021] [Revised: 03/23/2021] [Accepted: 03/25/2021] [Indexed: 01/18/2023] Open
Abstract
Functional alterations in irritable bowel syndrome have been associated with defects in bioenergetics and the mitochondrial network. Effects of high fat, adequate-protein, low carbohydrate ketogenic diet (KD) involve oxidative stress, inflammation, mitochondrial function, and biogenesis. The aim was to evaluate the KD efficacy in reducing the effects of stress on gut mitochondria. Newborn Wistar rats were exposed to maternal deprivation to induce IBS in adulthood. Intestinal inflammation (COX-2 and TRL-4); cellular redox status (SOD 1, SOD 2, PrxIII, mtDNA oxidatively modified purines); mitochondrial biogenesis (PPAR-γ, PGC-1α, COX-4, mtDNA content); and autophagy (Beclin-1, LC3 II) were evaluated in the colon of exposed rats fed with KD (IBD-KD) or standard diet (IBS-Std), and in unexposed controls (Ctrl). IBS-Std rats showed dysfunctional mitochondrial biogenesis (PPAR-γ, PGC-1α, COX-4, and mtDNA contents lower than in Ctrl) associated with inflammation and increased oxidative stress (higher levels of COX-2 and TLR-4, SOD 1, SOD 2, PrxIII, and oxidatively modified purines than in Ctrl). Loss of autophagy efficacy appeared from reduced levels of Beclin-1 and LC3 II. Feeding of animals with KD elicited compensatory mechanisms able to reduce inflammation, oxidative stress, restore mitochondrial function, and baseline autophagy, possibly via the upregulation of the PPAR-γ/PGC-1α axis.
Collapse
|
7
|
Dissection of two routes to naïve pluripotency using different kinase inhibitors. Nat Commun 2021; 12:1863. [PMID: 33767186 PMCID: PMC7994667 DOI: 10.1038/s41467-021-22181-5] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2020] [Accepted: 03/04/2021] [Indexed: 01/31/2023] Open
Abstract
Embryonic stem cells (ESCs) can be maintained in the naïve state through inhibition of Mek1/2 and Gsk3 (2i). A relevant effect of 2i is the inhibition of Cdk8/19, which are negative regulators of the Mediator complex, responsible for the activity of enhancers. Inhibition of Cdk8/19 (Cdk8/19i) stimulates enhancers and, similar to 2i, stabilizes ESCs in the naïve state. Here, we use mass spectrometry to describe the molecular events (phosphoproteome, proteome, and metabolome) triggered by 2i and Cdk8/19i on ESCs. Our data reveal widespread commonalities between these two treatments, suggesting overlapping processes. We find that post-transcriptional de-repression by both 2i and Cdk8/19i might support the mitochondrial capacity of naive cells. However, proteome reprogramming in each treatment is achieved by different mechanisms. Cdk8/19i acts directly on the transcriptional machinery, activating key identity genes to promote the naïve program. In contrast, 2i stabilizes the naïve circuitry through, in part, de-phosphorylation of downstream transcriptional effectors.
Collapse
|
8
|
The Ubiquitin Ligase SIAH2 Negatively Regulates Glucocorticoid Receptor Activity and Abundance. Biomedicines 2020; 9:biomedicines9010022. [PMID: 33396678 PMCID: PMC7823448 DOI: 10.3390/biomedicines9010022] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2020] [Revised: 12/22/2020] [Accepted: 12/24/2020] [Indexed: 11/25/2022] Open
Abstract
Glucocorticoids are clinically essential drugs used routinely to control inflammation. However, a host of metabolic side effects manifests upon usage beyond a few days. In the present study, we tested the hypothesis that seven-in-absentia mammalian homolog-2 (SIAH2), a ubiquitin ligase that regulates adipogenesis, is important for controlling adipocyte size, inflammation, and the ability of adipose tissue to expand in response to a glucocorticoid challenge. Using mice with global deletion of SIAH2 exposed or not to corticosterone, we found that adipocytes are larger in response to glucocorticoids in the absence of SIAH2. In addition, SIAH2 regulates glucocorticoid receptor (GR) transcriptional activity and total GR protein abundance. Moreover, these studies reveal that there is an increased expression of genes involved in fibrosis and inflammatory signaling pathways found in white adipose tissue in response to glucocorticoids in the absence of SIAH2. In summary, this is the first study to identify a role for SIAH2 to regulate transcriptional activity and abundance of the GR, which leads to alterations in adipose tissue size and gene expression during in vivo exposure to glucocorticoids.
Collapse
|
9
|
Fernando LM, Elliot J, Allen AK. The Caenorhabditis elegans proteasome subunit RPN-12 is required for hermaphrodite germline sex determination and oocyte quality. Dev Dyn 2020; 250:145-159. [PMID: 32767462 DOI: 10.1002/dvdy.235] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2020] [Revised: 07/16/2020] [Accepted: 07/31/2020] [Indexed: 12/26/2022] Open
Abstract
BACKGROUND The proteasome is a multi-subunit complex and a major proteolytic machinery in cells. Most subunits are essential for proteasome function, and depletion of individual subunits normally results in lethality. RPN-12/Rpn12/PSMD8 is a lid subunit of the 19S regulatory particle (RP) of the 26S proteasome. Studies in Caenorhabditis elegans demonstrated that RNAi depletion of RPN-12 does not result in lethality. RPN-12 has not been well studied in higher eukaryotes. In this study, we investigate the biological significance of RPN-12 in C. elegans. RESULTS We found that the null mutant rpn-12(av93) did not cause major impairment of the proteolytic activity of the proteasome. Most rpn-12(av93) hermaphrodites lack sperm leading to feminization of the germ line that can be partially rescued by mating to males. The lack of sperm phenotype can be suppressed by downregulation of TRA-1, a player in the hermaphrodite germline sex determination pathway. Also, rpn-12(av93) animals show significant nuclear accumulation of the meiotic kinase WEE-1.3, a protein predominantly localized to the perinuclear region. Interestingly, chemical inhibition of the proteasome did not cause nuclear accumulation of WEE-1.3. CONCLUSIONS RPN-12 plays a previously unknown role in oogenesis and the germline sex determination pathway in C. elegans hermaphrodites.
Collapse
Affiliation(s)
- Lourds M Fernando
- Department of Biology, Howard University, Washington, District of Columbia, USA
| | - Jeandele Elliot
- Department of Biology, Howard University, Washington, District of Columbia, USA
| | - Anna K Allen
- Department of Biology, Howard University, Washington, District of Columbia, USA
| |
Collapse
|
10
|
Sweeney MA, Iakova P, Maneix L, Shih FY, Cho HE, Sahin E, Catic A. The ubiquitin ligase Cullin-1 associates with chromatin and regulates transcription of specific c-MYC target genes. Sci Rep 2020; 10:13942. [PMID: 32811853 PMCID: PMC7435197 DOI: 10.1038/s41598-020-70610-0] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2020] [Accepted: 07/29/2020] [Indexed: 12/16/2022] Open
Abstract
Transcription is regulated through a dynamic interplay of DNA-associated proteins, and the composition of gene-regulatory complexes is subject to continuous adjustments. Protein alterations include post-translational modifications and elimination of individual polypeptides. Spatially and temporally controlled protein removal is, therefore, essential for gene regulation and accounts for the short half-life of many transcription factors. The ubiquitin-proteasome system is responsible for site- and target-specific ubiquitination and protein degradation. Specificity of ubiquitination is conferred by ubiquitin ligases. Cullin-RING complexes, the largest family of ligases, require multi-unit assembly around one of seven cullin proteins. To investigate the direct role of cullins in ubiquitination of DNA-bound proteins and in gene regulation, we analyzed their subcellular locations and DNA-affinities. We found CUL4A and CUL7 to be largely excluded from the nucleus, whereas CUL4B was primarily nuclear. CUL1,2,3, and 5 showed mixed cytosolic and nuclear expression. When analyzing chromatin affinity of individual cullins, we discovered that CUL1 preferentially associated with active promoter sequences and co-localized with 23% of all DNA-associated protein degradation sites. CUL1 co-distributed with c-MYC and specifically repressed nuclear-encoded mitochondrial and splicing-associated genes. These studies underscore the relevance of spatial control in chromatin-associated protein ubiquitination and define a novel role for CUL1 in gene repression.
Collapse
Affiliation(s)
- Melanie A Sweeney
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX, USA
- Huffington Center on Aging, Baylor College of Medicine, Houston, TX, USA
- Stem Cells and Regenerative Medicine Center, Baylor College of Medicine, Houston, TX, USA
- Dan L. Duncan Comprehensive Cancer Center, Baylor College of Medicine, Houston, TX, USA
- Center for Cell and Gene Therapy, Baylor College of Medicine, Houston, TX, USA
| | - Polina Iakova
- Huffington Center on Aging, Baylor College of Medicine, Houston, TX, USA
- Stem Cells and Regenerative Medicine Center, Baylor College of Medicine, Houston, TX, USA
- Dan L. Duncan Comprehensive Cancer Center, Baylor College of Medicine, Houston, TX, USA
- Center for Cell and Gene Therapy, Baylor College of Medicine, Houston, TX, USA
| | - Laure Maneix
- Huffington Center on Aging, Baylor College of Medicine, Houston, TX, USA
- Stem Cells and Regenerative Medicine Center, Baylor College of Medicine, Houston, TX, USA
- Dan L. Duncan Comprehensive Cancer Center, Baylor College of Medicine, Houston, TX, USA
- Center for Cell and Gene Therapy, Baylor College of Medicine, Houston, TX, USA
| | - Fu-Yuan Shih
- Huffington Center on Aging, Baylor College of Medicine, Houston, TX, USA
- Stem Cells and Regenerative Medicine Center, Baylor College of Medicine, Houston, TX, USA
- Dan L. Duncan Comprehensive Cancer Center, Baylor College of Medicine, Houston, TX, USA
- Center for Cell and Gene Therapy, Baylor College of Medicine, Houston, TX, USA
| | - Hannah E Cho
- Huffington Center on Aging, Baylor College of Medicine, Houston, TX, USA
- Rice University Undergraduate School of Social Sciences, Houston, TX, USA
| | - Ergun Sahin
- Huffington Center on Aging, Baylor College of Medicine, Houston, TX, USA
| | - Andre Catic
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX, USA.
- Huffington Center on Aging, Baylor College of Medicine, Houston, TX, USA.
- Stem Cells and Regenerative Medicine Center, Baylor College of Medicine, Houston, TX, USA.
- Dan L. Duncan Comprehensive Cancer Center, Baylor College of Medicine, Houston, TX, USA.
- Center for Cell and Gene Therapy, Baylor College of Medicine, Houston, TX, USA.
- Michael E. DeBakey Veterans Affairs Medical Center, Houston, TX, USA.
| |
Collapse
|
11
|
The ion channels and transporters gene expression profile indicates a shift in excitability and metabolisms during malignant progression of Follicular Lymphoma. Sci Rep 2019; 9:8586. [PMID: 31197180 PMCID: PMC6565741 DOI: 10.1038/s41598-019-44661-x] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2016] [Accepted: 05/21/2019] [Indexed: 12/13/2022] Open
Abstract
The definition of the gene expression profile of genes encoding Ion Channels and Transporters (ICT-GEP) represents a novel and attracting aspect in cancer. We determined the ICT-GEP of Follicular Lymphoma (FL), and compared it with that of the more aggressive Diffuse Large B Cell Lymphoma (DLBCL). cDNA microarray data were collected both from patients enrolled for this study, and from public datasets. In FL the ICT-GEP indicated the overexpression of both the K+ channel encoding gene KCNN4, and SLC2A1, which encodes the Glut1 glucose transporter. SLC2A1 turned out to represent the hub of a functional network, connecting channels and transporters in FL. Relapsed FL patients were characterised by 38 differentially expressed ICT genes, among which ATP9A, SLC2A1 and KCNN4 were under-expressed, indicating a down-regulation of both excitability and glycolysis. A completely different profile of K+ channel encoding genes emerged in DLBCL accompanied by the over-expression of the fatty acid transporter-encoding gene SLC27A1 as well as of the metabolism regulator NCoR1. This indicates a change in excitability and a shift towards an oxidative metabolism in DLBCL. Overall, the ICT-GEP may contribute to identifying novel lymphoma biomarkers related to excitability and metabolic pathways, with particular relevance for drug resistant, relapsed FL.
Collapse
|
12
|
Miller KN, Clark JP, Anderson RM. Mitochondrial regulator PGC-1a-Modulating the modulator. ACTA ACUST UNITED AC 2019; 5:37-44. [PMID: 31406949 DOI: 10.1016/j.coemr.2019.02.002] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Peroxisome proliferator-activated receptor gamma coactivator-1 alpha (PGC-1a) is a central regulator of metabolism that is poised at the intersection of myriad intracellular signaling pathways. In this brief update, we discuss regulation of PGC-1a at multiple levels, including transcriptional, post-transcriptional, and post-translational modifications. We discuss recently identified small molecule effectors of PGC-1a that offer translational potential and promise new insight into PGC-1a biology. We highlight novel mechanistic insights relating to PGC-1a's interactions with RNA to enhance transcription and potentially influence transcript processing. Finally, we place these exciting new data in the context of aging biology, offering PGC-1a as a candidate target with terrific potential in anti-aging interventions.
Collapse
Affiliation(s)
- Karl N Miller
- Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, USA
| | - Josef P Clark
- Department of Medicine, School of Medicine and Public Health, University of Wisconsin-Madison, USA
| | - Rozalyn M Anderson
- Department of Medicine, School of Medicine and Public Health, University of Wisconsin-Madison, USA.,GRECC, William S. Middleton Memorial Veterans Hospital, Madison WI, USA
| |
Collapse
|
13
|
Reisz JA, Barrett AS, Nemkov T, Hansen KC, D'Alessandro A. When nature's robots go rogue: exploring protein homeostasis dysfunction and the implications for understanding human aging disease pathologies. Expert Rev Proteomics 2018; 15:293-309. [PMID: 29540077 PMCID: PMC6174679 DOI: 10.1080/14789450.2018.1453362] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2017] [Accepted: 03/13/2018] [Indexed: 12/19/2022]
Abstract
INTRODUCTION Proteins have been historically regarded as 'nature's robots': Molecular machines that are essential to cellular/extracellular physical mechanical properties and catalyze key reactions for cell/system viability. However, these robots are kept in check by other protein-based machinery to preserve proteome integrity and stability. During aging, protein homeostasis is challenged by oxidation, decreased synthesis, and increasingly inefficient mechanisms responsible for repairing or degrading damaged proteins. In addition, disruptions to protein homeostasis are hallmarks of many neurodegenerative diseases and diseases disproportionately affecting the elderly. Areas covered: Here we summarize age- and disease-related changes to the protein machinery responsible for preserving proteostasis and describe how both aging and disease can each exacerbate damage initiated by the other. We focus on alteration of proteostasis as an etiological or phenomenological factor in neurodegenerative diseases such as Alzheimer's, Parkinson's, and Huntington's, along with Down syndrome, ophthalmic pathologies, and cancer. Expert commentary: Understanding the mechanisms of proteostasis and their dysregulation in health and disease will represent an essential breakthrough in the treatment of many (senescence-associated) pathologies. Strides in this field are currently underway and largely attributable to the introduction of high-throughput omics technologies and their combination with novel approaches to explore structural and cross-link biochemistry.
Collapse
Affiliation(s)
- Julie A Reisz
- a Department of Biochemistry and Molecular Genetics , University of Colorado Denver - Anschutz Medical Campus , Aurora , CO , USA
| | - Alexander S Barrett
- a Department of Biochemistry and Molecular Genetics , University of Colorado Denver - Anschutz Medical Campus , Aurora , CO , USA
| | - Travis Nemkov
- a Department of Biochemistry and Molecular Genetics , University of Colorado Denver - Anschutz Medical Campus , Aurora , CO , USA
| | - Kirk C Hansen
- a Department of Biochemistry and Molecular Genetics , University of Colorado Denver - Anschutz Medical Campus , Aurora , CO , USA
| | - Angelo D'Alessandro
- a Department of Biochemistry and Molecular Genetics , University of Colorado Denver - Anschutz Medical Campus , Aurora , CO , USA
| |
Collapse
|
14
|
Strand NS, Allen JM, Ghulam M, Taylor MR, Munday RK, Carrillo M, Movsesyan A, Zayas RM. Dissecting the function of Cullin-RING ubiquitin ligase complex genes in planarian regeneration. Dev Biol 2018; 433:210-217. [PMID: 29291974 DOI: 10.1016/j.ydbio.2017.10.011] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2017] [Revised: 09/25/2017] [Accepted: 10/11/2017] [Indexed: 12/26/2022]
Abstract
The ubiquitin system plays a role in nearly every aspect of eukaryotic cell biology. The enzymes responsible for transferring ubiquitin onto specific substrates are the E3 ubiquitin ligases, a large and diverse family of proteins, for which biological roles and target substrates remain largely undefined. Studies using model organisms indicate that ubiquitin signaling mediates key steps in developmental processes and tissue regeneration. Here, we used the freshwater planarian, Schmidtea mediterranea, to investigate the role of Cullin-RING ubiquitin ligase (CRL) complexes in stem cell regulation during regeneration. We identified six S. mediterranea cullin genes, and used RNAi to uncover roles for homologs of Cullin-1, -3 and -4 in planarian regeneration. The cullin-1 RNAi phenotype included defects in blastema formation, organ regeneration, lesions, and lysis. To further investigate the function of cullin-1-mediated cellular processes in planarians, we examined genes encoding the adaptor protein Skp1 and F-box substrate-recognition proteins that are predicted to partner with Cullin-1. RNAi against skp1 resulted in phenotypes similar to cullin-1 RNAi, and an RNAi screen of the F-box genes identified 19 genes that recapitulated aspects of cullin-1 RNAi, including ones that in mammals are involved in stem cell regulation and cancer biology. Our data provides evidence that CRLs play discrete roles in regenerative processes and provide a platform to investigate how CRLs regulate stem cells in vivo.
Collapse
Affiliation(s)
- Nicholas S Strand
- Department of Biology, San Diego State University, San Diego, CA 92182, USA
| | - John M Allen
- Department of Biology, San Diego State University, San Diego, CA 92182, USA
| | - Mahjoobah Ghulam
- Department of Biology, San Diego State University, San Diego, CA 92182, USA
| | - Matthew R Taylor
- Department of Biology, San Diego State University, San Diego, CA 92182, USA
| | - Roma K Munday
- Department of Biology, San Diego State University, San Diego, CA 92182, USA
| | - Melissa Carrillo
- Department of Biology, San Diego State University, San Diego, CA 92182, USA
| | - Artem Movsesyan
- Department of Biology, San Diego State University, San Diego, CA 92182, USA
| | - Ricardo M Zayas
- Department of Biology, San Diego State University, San Diego, CA 92182, USA.
| |
Collapse
|
15
|
Franz A, Ackermann L, Hoppe T. Ring of Change: CDC48/p97 Drives Protein Dynamics at Chromatin. Front Genet 2016; 7:73. [PMID: 27200082 PMCID: PMC4853748 DOI: 10.3389/fgene.2016.00073] [Citation(s) in RCA: 67] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2016] [Accepted: 04/16/2016] [Indexed: 12/31/2022] Open
Abstract
The dynamic composition of proteins associated with nuclear DNA is a fundamental property of chromosome biology. In the chromatin compartment dedicated protein complexes govern the accurate synthesis and repair of the genomic information and define the state of DNA compaction in vital cellular processes such as chromosome segregation or transcription. Unscheduled or faulty association of protein complexes with DNA has detrimental consequences on genome integrity. Consequently, the association of protein complexes with DNA is remarkably dynamic and can respond rapidly to cellular signaling events, which requires tight spatiotemporal control. In this context, the ring-like AAA+ ATPase CDC48/p97 emerges as a key regulator of protein complexes that are marked with ubiquitin or SUMO. Mechanistically, CDC48/p97 functions as a segregase facilitating the extraction of substrate proteins from the chromatin. As such, CDC48/p97 drives molecular reactions either by directed disassembly or rearrangement of chromatin-bound protein complexes. The importance of this mechanism is reflected by human pathologies linked to p97 mutations, including neurodegenerative disorders, oncogenesis, and premature aging. This review focuses on the recent insights into molecular mechanisms that determine CDC48/p97 function in the chromatin environment, which is particularly relevant for cancer and aging research.
Collapse
Affiliation(s)
- André Franz
- Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases, Institute for Genetics, University of Cologne Cologne, Germany
| | - Leena Ackermann
- Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases, Institute for Genetics, University of Cologne Cologne, Germany
| | - Thorsten Hoppe
- Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases, Institute for Genetics, University of Cologne Cologne, Germany
| |
Collapse
|