1
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Down-regulation of HLA-B-associated transcript 3 impairs the tumoricidal effect of natural killer cells through promoting the T cell immunoglobulin and mucin domain-containing-3 signaling in a mouse head and neck squamous cell carcinoma model. Immunobiology 2021; 227:152127. [PMID: 34968777 DOI: 10.1016/j.imbio.2021.152127] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2021] [Revised: 07/09/2021] [Accepted: 07/25/2021] [Indexed: 11/22/2022]
Abstract
Head and neck squamous cell carcinoma (HNSCC) arises from the malignant mucosal epithelium of the oral cavity, pharynx, and larynx. Natural killer (NK) cells are fundamental immune cells shaping the anti-HNSCC response. Elucidation of the regulatory mechanisms of NK cell activity is crucial for understanding anti-HNSCC immunity. In this study, we characterized the expression and function of HLA-B-associated transcript 3 (Bat3) in NK cells in a mouse HNSCC model. We found that Bat3 expression was down-regulated in HNSCC-infiltrating NK cells. SCC VII, the mouse HNSCC cell line used in this model, induced Bat3 downregulation through direct cell-to-cell contact. By applying lentivirus-mediated silencing of Bat3, we discovered that Bat3 knockdown impaired the tumoricidal effect of NK cells on SCC VII cells and Hepa1-6RAE1, a genetically modified liver cancer cell line. Furthermore, Bat3 knockdown resulted in a significant decrease in perforin, granzyme B, interferon-γ, and tumor necrosis factor-α in NK cells upon co-culture with SCC VII cells. Further investigations revealed that Bat3 knockdown promoted the binding of T cell immunoglobulin and mucin domain-containing-3 (Tim-3) to Fyn and thus activated the Tim-3 signaling. Blockade of Tim-3 with a neutralizing Tim-3 antibody counteracted the effect of Bat3 knockdown on NK cell cytotoxicity. Taken together, our data suggest that HNSCC might down-regulate Bat3 expression to augment Tim-3 signaling and ultimately suppress the tumoricidal activity of NK cells. This study unveils a novel mechanism by which HNSCC evades NK cell killing, and sheds light on designing novel anti-HNSCC immunotherapy targeting Bat3 and Tim-3 signaling.
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2
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Zhang R, Cui D, Xue T, Lang Y, Zhang Y, Li L, Sun H, Kuang Y, Li G, Tang J. HLA-B-associated transcript 3 (Bat3) stabilizes and activates p53 in a HAUSP-dependent manner. J Mol Cell Biol 2021; 12:99-112. [PMID: 31647545 PMCID: PMC7109604 DOI: 10.1093/jmcb/mjz102] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2019] [Revised: 07/12/2019] [Accepted: 08/26/2019] [Indexed: 01/06/2023] Open
Abstract
The p53 pathway is a highly complex signaling network including several key regulators. HAUSP is a critical component of the p53 pathway acting as a deubiquitinase for both p53 and its key repressor Mdm2. Here, we identified a novel HAUSP-interacting protein, HLA-B-associated transcript 3 (Bat3) and found it to be capable of inducing p53 stabilization and activation via a HAUSP-dependent mechanism, resulting in cell growth inhibition. Surprisingly, the deubiquitylating enzymatic activity of HAUSP was not required for this phenomenon. Co-immunoprecipitation showed that p53 coexisted in a complex with Bat3 and HAUSP in vivo, and HAUSP may serve as a binding mediator to enhance the interaction between p53 and Bat3. Further studies revealed that formation of this three-protein complex interfered with the binding of p53 to its proteasome receptor S5a and promoted the accumulation of p53 in nucleus. Notably, Mdm2 protein abundance is also regulated by Bat3 in the presence of HAUSP. Overexpression of Bat3 and HAUSP increases Mdm2 protein levels without influencing the p53–Mdm2 interaction and Mdm2-mediated p53 ubiquitination, indicating that Bat3–HAUSP-mediated protein stabilization is not specific to p53 and different mechanisms may be involved in Bat3-mediated regulation of p53–Mdm2 pathway. Together, our study unravels a novel mechanism by which p53 is stabilized and activated by HAUSP-mediated interaction with Bat3 and implies that Bat3 might function as a tumor suppressor through the stabilization of p53.
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Affiliation(s)
- Rui Zhang
- Department of Basic Veterinary, College of Veterinary Medicine, China Agricultural University, Beijing 100193, China.,State Key Laboratory of Agrobiotechnology, China Agricultural University, Beijing 100193, China
| | - Di Cui
- Department of Basic Veterinary, College of Veterinary Medicine, China Agricultural University, Beijing 100193, China.,State Key Laboratory of Agrobiotechnology, China Agricultural University, Beijing 100193, China.,Clinical Research Institute, Zhejiang Provincial People's Hospital, People's Hospital of Hangzhou Medical College, Hangzhou 310014, China
| | - Teng Xue
- Department of Basic Veterinary, College of Veterinary Medicine, China Agricultural University, Beijing 100193, China.,State Key Laboratory of Agrobiotechnology, China Agricultural University, Beijing 100193, China
| | - Yue Lang
- Department of Basic Veterinary, College of Veterinary Medicine, China Agricultural University, Beijing 100193, China.,State Key Laboratory of Agrobiotechnology, China Agricultural University, Beijing 100193, China
| | - Yunfan Zhang
- Department of Basic Veterinary, College of Veterinary Medicine, China Agricultural University, Beijing 100193, China.,State Key Laboratory of Agrobiotechnology, China Agricultural University, Beijing 100193, China
| | - Lianjie Li
- Department of Basic Veterinary, College of Veterinary Medicine, China Agricultural University, Beijing 100193, China.,State Key Laboratory of Agrobiotechnology, China Agricultural University, Beijing 100193, China
| | - Haili Sun
- Department of Basic Veterinary, College of Veterinary Medicine, China Agricultural University, Beijing 100193, China.,State Key Laboratory of Agrobiotechnology, China Agricultural University, Beijing 100193, China
| | - Yu Kuang
- Department of Basic Veterinary, College of Veterinary Medicine, China Agricultural University, Beijing 100193, China
| | - Gebin Li
- Department of Clinical Veterinary, College of Veterinary Medicine, China Agricultural University, Beijing 100193, China
| | - Jun Tang
- Department of Basic Veterinary, College of Veterinary Medicine, China Agricultural University, Beijing 100193, China.,State Key Laboratory of Agrobiotechnology, China Agricultural University, Beijing 100193, China
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3
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The Chaperone BAG6 Regulates Cellular Homeostasis between Autophagy and Apoptosis by Holding LC3B. iScience 2020; 23:101708. [PMID: 33241194 PMCID: PMC7674511 DOI: 10.1016/j.isci.2020.101708] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2019] [Revised: 07/27/2020] [Accepted: 10/16/2020] [Indexed: 12/15/2022] Open
Abstract
AMFR/gp78 and USP13 are a pair of ubiquitin ligase and deubiquitinase that ensure the accuracy of endoplasmic reticulum-associated degradation (ERAD). Depletion of USP13 leads to caspase activation and cleavage of the ERAD chaperone BAG6, which is reversed by knockdown of AMFR. However, the mechanism and physiological relevance of this regulation are still unclear. Here, by using the NEDDylator system, we screened out TXN as a substrate of AMFR and USP13 and showed its involvement in regulating CASP3 activation and BAG6 cleavage. Furthermore, we showed that the cleaved N-terminal BAG6 is located in the cytosol and interacts with both LC3B-I and unprocessed form of LC3B (Pro-LC3B) through the LIR1 motif to suppress autophagy. An NMR approach verified the direct interaction between BAG6 LIR1 and LC3B-I or Pro-LC3B. Collectively, our findings uncover a mechanism that converts BAG6 from an ERAD regulator to an autophagy tuner and apoptosis inducer during ER stress.
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4
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Hayashishita M, Kawahara H, Yokota N. BAG6 deficiency induces mis-distribution of mitochondrial clusters under depolarization. FEBS Open Bio 2019; 9:1281-1291. [PMID: 31125507 PMCID: PMC6609563 DOI: 10.1002/2211-5463.12677] [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: 11/19/2018] [Revised: 04/16/2019] [Accepted: 05/22/2019] [Indexed: 01/09/2023] Open
Abstract
Accumulation of damaged mitochondria is implicated in a number of neurodegenerative disorders, including Parkinson's disease. Therefore, the machinery for mitochondrial quality control is important for the prevention of such diseases. It has been reported that Parkin‐ and p62/sequestosome 1 (SQSTM1)‐mediated clustering and subsequent elimination of damaged mitochondria (termed mitophagy) are critical for maintaining the quality of mitochondria under stress induced by uncoupling agents such as carbonyl cyanide m‐chlorophenyl hydrazone. However, the molecular mechanisms underlying mitochondrial translocation to the perinuclear region during mitophagy have not been adequately addressed to date. In this study, we found that BCL2‐associated athanogene 6 (BAG6; also known as BAT3 or Scythe) is required for this process. Indeed, RNA interference‐mediated depletion of endogenous BAG6 prevented Parkin‐dependent relocalization of mitochondrial clusters to the perinuclear cytoplasmic region, whereas BAG6 knockdown did not affect the translocation of Parkin and p62/SQSTM1 to the depolarized mitochondria and subsequent aggregation. These results suggest that BAG6 is essential for cytoplasmic redistribution, but not for clustering, of damaged mitochondria.
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Affiliation(s)
- Mizuki Hayashishita
- Laboratory of Cell Biology and Biochemistry, Department of Biological Sciences, Tokyo Metropolitan University, Japan
| | - Hiroyuki Kawahara
- Laboratory of Cell Biology and Biochemistry, Department of Biological Sciences, Tokyo Metropolitan University, Japan
| | - Naoto Yokota
- Laboratory of Cell Biology and Biochemistry, Department of Biological Sciences, Tokyo Metropolitan University, Japan
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5
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Takahashi T, Minami S, Tsuchiya Y, Tajima K, Sakai N, Suga K, Hisanaga SI, Ohbayashi N, Fukuda M, Kawahara H. Cytoplasmic control of Rab family small GTPases through BAG6. EMBO Rep 2019; 20:embr.201846794. [PMID: 30804014 PMCID: PMC6446207 DOI: 10.15252/embr.201846794] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2018] [Revised: 01/25/2019] [Accepted: 01/29/2019] [Indexed: 11/18/2022] Open
Abstract
Rab family small GTPases are master regulators of distinct steps of intracellular vesicle trafficking in eukaryotic cells. GDP‐bound cytoplasmic forms of Rab proteins are prone to aggregation due to the exposure of hydrophobic groups but the machinery that determines the fate of Rab species in the cytosol has not been elucidated in detail. In this study, we find that BAG6 (BAT3/Scythe) predominantly recognizes a cryptic portion of GDP‐associated Rab8a, while its major GTP‐bound active form is not recognized. The hydrophobic residues of the Switch I region of Rab8a are essential for its interaction with BAG6 and the degradation of GDP‐Rab8a via the ubiquitin‐proteasome system. BAG6 prevents the excess accumulation of inactive Rab8a, whose accumulation impairs intracellular membrane trafficking. BAG6 binds not only Rab8a but also a functionally distinct set of Rab family proteins, and is also required for the correct distribution of Golgi and endosomal markers. From these observations, we suggest that Rab proteins represent a novel set of substrates for BAG6, and the BAG6‐mediated pathway is associated with the regulation of membrane vesicle trafficking events in mammalian cells.
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Affiliation(s)
- Toshiki Takahashi
- Laboratory of Cell Biology and Biochemistry, Department of Biological Sciences, Tokyo Metropolitan University, Tokyo, Japan
| | - Setsuya Minami
- Laboratory of Cell Biology and Biochemistry, Department of Biological Sciences, Tokyo Metropolitan University, Tokyo, Japan
| | - Yugo Tsuchiya
- Laboratory of Cell Biology and Biochemistry, Department of Biological Sciences, Tokyo Metropolitan University, Tokyo, Japan
| | - Kazu Tajima
- Laboratory of Cell Biology and Biochemistry, Department of Biological Sciences, Tokyo Metropolitan University, Tokyo, Japan
| | - Natsumi Sakai
- Laboratory of Cell Biology and Biochemistry, Department of Biological Sciences, Tokyo Metropolitan University, Tokyo, Japan
| | - Kei Suga
- Department of Cell Physiology, Kyorin University School of Medicine, Mitaka, Japan.,Department of Chemistry, Kyorin University School of Medicine, Mitaka, Japan
| | - Shin-Ichi Hisanaga
- Laboratory of Molecular Neuroscience, Department of Biological Sciences, Tokyo Metropolitan University, Tokyo, Japan
| | - Norihiko Ohbayashi
- Department of Physiological Chemistry, Faculty of Medicine, University of Tsukuba, Tsukuba, Japan
| | - Mitsunori Fukuda
- Department of Integrative Life Sciences, Graduate School of Life Sciences, Tohoku University, Sendai, Japan
| | - Hiroyuki Kawahara
- Laboratory of Cell Biology and Biochemistry, Department of Biological Sciences, Tokyo Metropolitan University, Tokyo, Japan
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6
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Kondo M, Noguchi A, Matsuura Y, Shimada M, Yokota N, Kawahara H. Novel phosphorelay-dependent control of ZFP36L1 protein during the cell cycle. Biochem Biophys Res Commun 2018; 501:387-393. [DOI: 10.1016/j.bbrc.2018.04.212] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2018] [Accepted: 04/26/2018] [Indexed: 10/16/2022]
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7
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Elimination of a signal sequence-uncleaved form of defective HLA protein through BAG6. Sci Rep 2017; 7:14545. [PMID: 29109525 PMCID: PMC5674028 DOI: 10.1038/s41598-017-14975-9] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2017] [Accepted: 10/16/2017] [Indexed: 12/15/2022] Open
Abstract
A portion of newly synthesized transmembrane domain proteins tend to fail to assemble correctly in the lumen of the endoplasmic reticulum, thus resulting in the production of a signal sequence-uncleaved form of the defective species. Although the efficient degradation of these mistargeted polypeptides is crucial, the molecular mechanism of their elimination pathway has not been adequately characterized. In this study, we focused on one such cryptic portion of a defective transmembrane domain protein, HLA-A, and show that a part of HLA-A is produced as a signal sequence-uncleaved labile species that is immediately targeted to the degradation pathway. We found that both BAG6 and proteasomes are indispensable for elimination of mislocalized HLA-A species. Furthermore, defective HLA-A is subjected to BAG6-dependent solubilization in the cytoplasm. These observations suggest that BAG6 acts as a critical factor for proteasome-mediated degradation of mislocalized HLA-A with a non-cleaved signal sequence at its N-terminus.
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8
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LI YIN, CONG YAN, ZHAO YUN. Network motif-based method for identifying coronary artery disease. Exp Ther Med 2016; 12:257-261. [PMID: 27347046 PMCID: PMC4907106 DOI: 10.3892/etm.2016.3299] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2015] [Accepted: 04/01/2016] [Indexed: 11/13/2022] Open
Abstract
The present study aimed to develop a more efficient method for identifying coronary artery disease (CAD) than the conventional method using individual differentially expressed genes (DEGs). GSE42148 gene microarray data were downloaded, preprocessed and screened for DEGs. Additionally, based on transcriptional regulation data obtained from ENCODE database and protein-protein interaction data from the HPRD, the common genes were downloaded and compared with genes annotated from gene microarrays to screen additional common genes in order to construct an integrated regulation network. FANMOD was then used to detect significant three-gene network motifs. Subsequently, GlobalAncova was used to screen differential three-gene network motifs between the CAD group and the normal control data from GSE42148. Genes involved in the differential network motifs were then subjected to functional annotation and pathway enrichment analysis. Finally, clustering analysis of the CAD and control samples was performed based on individual DEGs and the top 20 network motifs identified. In total, 9,008 significant three-node network motifs were detected from the integrated regulation network; these were categorized into 22 interaction modes, each containing a minimum of one transcription factor. Subsequently, 1,132 differential network motifs involving 697 genes were screened between the CAD and control group. The 697 genes were enriched in 154 gene ontology terms, including 119 biological processes, and 14 KEGG pathways. Identifying patients with CAD based on the top 20 network motifs provided increased accuracy compared with the conventional method based on individual DEGs. The results of the present study indicate that the network motif-based method is more efficient and accurate for identifying CAD patients than the conventional method based on individual DEGs.
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Affiliation(s)
- YIN LI
- Emergency Department, Huadong Hospital, Fudan University, Shanghai 200040, P.R. China
| | - YAN CONG
- Emergency Department, Huadong Hospital, Fudan University, Shanghai 200040, P.R. China
| | - YUN ZHAO
- Emergency Department, Huadong Hospital, Fudan University, Shanghai 200040, P.R. China
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9
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Tanaka H, Takahashi T, Xie Y, Minami R, Yanagi Y, Hayashishita M, Suzuki R, Yokota N, Shimada M, Mizushima T, Kuwabara N, Kato R, Kawahara H. A conserved island of BAG6/Scythe is related to ubiquitin domains and participates in short hydrophobicity recognition. FEBS J 2015; 283:662-77. [PMID: 26663859 DOI: 10.1111/febs.13618] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2015] [Revised: 11/19/2015] [Accepted: 12/02/2015] [Indexed: 11/27/2022]
Abstract
BAG6 (also called Scythe) interacts with the exposed hydrophobic regions of newly synthesized proteins and escorts them to the degradation machinery through mechanisms that remain to be elucidated. In this study, we provide evidence that BAG6 physically interacts with the model defective protein substrate CL1 in a manner that depends directly on its short hydrophobicity. We found that the N terminus of BAG6 contains an evolutionarily conserved island tentatively designated the BAG6 ubiquitin-linked domain. Partial deletion of this domain in the BAG6 N-terminal fragment abolished in cell recognition of polyubiquitinated polypeptides as well as the hydrophobicity-mediated recognition of the CL1 degron in cell and in vitro. These observations suggest a mechanism whereby the BAG6 ubiquitin-linked domain provides a platform for discriminating substrates with shorter hydrophobicity stretches as a signal for defective proteins.
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Affiliation(s)
- Hirofumi Tanaka
- Department of Biological Sciences, Tokyo Metropolitan University, Japan
| | - Toshiki Takahashi
- Department of Biological Sciences, Tokyo Metropolitan University, Japan
| | - Yiming Xie
- Department of Biological Sciences, Tokyo Metropolitan University, Japan
| | - Ryosuke Minami
- Department of Biological Sciences, Tokyo Metropolitan University, Japan.,Graduate School of Pharmaceutical Sciences, Hokkaido University, Sapporo, Japan
| | - Yuko Yanagi
- Department of Biological Sciences, Tokyo Metropolitan University, Japan
| | | | - Rigel Suzuki
- Department of Biological Sciences, Tokyo Metropolitan University, Japan
| | - Naoto Yokota
- Department of Biological Sciences, Tokyo Metropolitan University, Japan
| | - Masumi Shimada
- Department of Biological Sciences, Tokyo Metropolitan University, Japan.,Graduate School of Pharmaceutical Sciences, Hokkaido University, Sapporo, Japan
| | - Tsunehiro Mizushima
- Picobiology Institute, Graduate School of Life Science, University of Hyogo, Japan
| | - Naoyuki Kuwabara
- Structural Biology Research Center, Photon Factory, IMSS, High Energy Accelerator Research Organization (KEK), Tsukuba, Japan
| | - Ryuichi Kato
- Structural Biology Research Center, Photon Factory, IMSS, High Energy Accelerator Research Organization (KEK), Tsukuba, Japan
| | - Hiroyuki Kawahara
- Department of Biological Sciences, Tokyo Metropolitan University, Japan
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10
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Kuwabara N, Minami R, Yokota N, Matsumoto H, Senda T, Kawahara H, Kato R. Structure of a BAG6 (Bcl-2-associated athanogene 6)-Ubl4a (ubiquitin-like protein 4a) complex reveals a novel binding interface that functions in tail-anchored protein biogenesis. J Biol Chem 2015; 290:9387-98. [PMID: 25713138 PMCID: PMC4392246 DOI: 10.1074/jbc.m114.631804] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2014] [Revised: 02/10/2015] [Indexed: 11/07/2022] Open
Abstract
BAG6 is an essential protein that functions in two distinct biological pathways, ubiquitin-mediated protein degradation of defective polypeptides and tail-anchored (TA) transmembrane protein biogenesis in mammals, although its structural and functional properties remain unknown. We solved a crystal structure of the C-terminal heterodimerization domains of BAG6 and Ubl4a and characterized their interaction biochemically. Unexpectedly, the specificity and structure of the C terminus of BAG6, which was previously classified as a BAG domain, were completely distinct from those of the canonical BAG domain. Furthermore, the tight association of BAG6 and Ubl4a resulted in modulation of Ubl4a protein stability in cells. Therefore, we propose to designate the Ubl4a-binding region of BAG6 as the novel BAG-similar (BAGS) domain. The structure of Ubl4a, which interacts with BAG6, is similar to the yeast homologue Get5, which forms a homodimer. These observations indicate that the BAGS domain of BAG6 promotes the TA protein biogenesis pathway in mammals by the interaction with Ubl4a.
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Affiliation(s)
- Naoyuki Kuwabara
- From the Structural Biology Research Center, Photon Factory, Institute of Materials Structure Science, High Energy Accelerator Research Organization (KEK), 1-1 Oho, Tsukuba, Ibaraki 305-0801, Japan and
| | - Ryosuke Minami
- the Department of Biological Sciences, Tokyo Metropolitan University, 1-1 Minami-Osawa, Hachioji, Tokyo 192-0397, Japan
| | - Naoto Yokota
- the Department of Biological Sciences, Tokyo Metropolitan University, 1-1 Minami-Osawa, Hachioji, Tokyo 192-0397, Japan
| | - Hirofumi Matsumoto
- the Department of Biological Sciences, Tokyo Metropolitan University, 1-1 Minami-Osawa, Hachioji, Tokyo 192-0397, Japan
| | - Toshiya Senda
- From the Structural Biology Research Center, Photon Factory, Institute of Materials Structure Science, High Energy Accelerator Research Organization (KEK), 1-1 Oho, Tsukuba, Ibaraki 305-0801, Japan and
| | - Hiroyuki Kawahara
- the Department of Biological Sciences, Tokyo Metropolitan University, 1-1 Minami-Osawa, Hachioji, Tokyo 192-0397, Japan
| | - Ryuichi Kato
- From the Structural Biology Research Center, Photon Factory, Institute of Materials Structure Science, High Energy Accelerator Research Organization (KEK), 1-1 Oho, Tsukuba, Ibaraki 305-0801, Japan and
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11
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Song ZQ, Yang LF, Wang YS, Zhu T, Zhou XM, Yin XM, Yao HQ, Zhao DM. Overexpression of BAT3 alleviates prion protein fragment PrP106-126-induced neuronal apoptosis. CNS Neurosci Ther 2014; 20:737-47. [PMID: 24629137 PMCID: PMC6493199 DOI: 10.1111/cns.12243] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2013] [Revised: 02/03/2014] [Accepted: 02/03/2014] [Indexed: 11/30/2022] Open
Abstract
BACKGROUNDS AND AIMS Prion diseases are a group of infectious neurodegenerative diseases characterized by neuronal death and degeneration. Human leukocyte antigen-B-associated transcript 3 (BAT3) is an important apoptosis regulator. We therefore investigated the interactions between BAT3 and prion protein and the potential role of BAT3 in PrP106-126-induced apoptosis. METHODS BAT3 and prion protein were overexpressed in Hela, Neuro2A, or primary neuronal cells by transfection with BAT3-HA or PRNP-EGFP expression plasmids and their relationship studied by immunofluorescence and Western blotting. The effect of BAT3 on PrP106-126-induced cytotoxicity and apoptosis was detected by the CCK-8 assay and terminal-deoxynucleotidyl transferase-mediated nick end labeling (TUNEL) assay. The expression of cytochrome c and Bcl-2 was examined by Western blotting. RESULTS BAT3 interacted with prion protein and enhanced PrP expression. After PrP106-126 peptide treated, BAT3 was transported from the nucleus to cytoplasm, increased cell viability, and protected neurons from PrP106-126-induced apoptosis through stabilizing the level of Bcl-2 protein and inhibiting the release of cytochrome c to cytoplasm. CONCLUSIONS Our present data showed a novel molecular mechanism of PrP106-126-induced apoptotic process regulation through the overexpression of BAT3, which may be important for the basic regulatory mechanism of neuron survival in prion diseases and associated neurodegenerative diseases in vivo.
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Affiliation(s)
- Zhi-Qi Song
- State Key Laboratories for Agrobiotechnology, Key Lab of Animal Epidemiology and Zoonosis, Ministry of Agriculture, National Animal Transmissible Spongiform Encephalopathy Laboratory, College of Veterinary Medicine, China Agricultural University, Beijing, China
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12
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Binici J, Koch J. BAG-6, a jack of all trades in health and disease. Cell Mol Life Sci 2014; 71:1829-37. [PMID: 24305946 PMCID: PMC11114047 DOI: 10.1007/s00018-013-1522-y] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2013] [Revised: 10/27/2013] [Accepted: 11/11/2013] [Indexed: 01/25/2023]
Abstract
BCL2-associated athanogene 6 (BAG-6) (also Bat-3/Scythe) was discovered as a gene product of the major histocompatibility complex class III locus. The Xenopus ortholog Scythe was first identified to act as an anti-apoptotic protein. Subsequent studies unraveled that the large BAG-6 protein contributes to a number of cellular processes, including apoptosis, gene regulation, protein synthesis, protein quality control, and protein degradation. In this context, BAG-6 acts as a multifunctional chaperone, which interacts with its target proteins for shuttling to distinct destinations. Nonetheless, as anticipated from its genomic localization, BAG-6 is involved in a variety of immunological pathways such as macrophage function and TH1 response. Most recently, BAG-6 was identified on the plasma membrane of dendritic cells and malignantly transformed cells where it serves as cellular ligand for the activating natural killer (NK) cell receptor NKp30 triggering NK cell cytotoxicity. Moreover, target cells were found to secrete soluble variants of BAG-6 and release BAG-6 on the surface of exosomes, which inhibit or activate NK cell cytotoxicity, respectively. These data suggest that the BAG-6 antigen is an important target to shape a directed immune response or to overcome tumor-immune escape strategies established by soluble BAG-6. This review summarizes the currently known functions of BAG-6, a fascinating multicompetent protein, in health and disease.
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Affiliation(s)
- Janina Binici
- NK Cell Biology, Institute for Tumor Biology and Experimental Therapy, Georg-Speyer-Haus, Paul-Ehrlich-Strasse 42–44, 60596 Frankfurt am Main, Germany
| | - Joachim Koch
- NK Cell Biology, Institute for Tumor Biology and Experimental Therapy, Georg-Speyer-Haus, Paul-Ehrlich-Strasse 42–44, 60596 Frankfurt am Main, Germany
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13
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BAT3 modulates p300-dependent acetylation of p53 and autophagy-related protein 7 (ATG7) during autophagy. Proc Natl Acad Sci U S A 2014; 111:4115-20. [PMID: 24591579 DOI: 10.1073/pnas.1313618111] [Citation(s) in RCA: 71] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Autophagy is regulated by posttranslational modifications, including acetylation. Here we show that HLA-B-associated transcript 3 (BAT3) is essential for basal and starvation-induced autophagy in embryonic day 18.5 BAT3(-/-) mouse embryos and in mouse embryonic fibroblasts (MEFs) through the modulation of p300-dependent acetylation of p53 and ATG7. Specifically, BAT3 increases p53 acetylation and proautophagic p53 target gene expression, while limiting p300-dependent acetylation of ATG7, a mechanism known to inhibit autophagy. In the absence of BAT3 or when BAT3 is located exclusively in the cytosol, autophagy is abrogated, ATG7 is hyperacetylated, p53 acetylation is abolished, and p300 accumulates in the cytosol, indicating that BAT3 regulates the nuclear localization of p300. In addition, the interaction between BAT3 and p300 is stronger in the cytosol than in the nucleus and, during starvation, the level of p300 decreases in the cytosol but increases in the nucleus only in the presence of BAT3. We conclude that BAT3 tightly controls autophagy by modulating p300 intracellular localization, affecting the accessibility of p300 to its substrates, p53 and ATG7.
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14
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Lee JG, Ye Y. Bag6/Bat3/Scythe: a novel chaperone activity with diverse regulatory functions in protein biogenesis and degradation. Bioessays 2013; 35:377-85. [PMID: 23417671 DOI: 10.1002/bies.201200159] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Upon emerging from the ribosome exiting tunnel, polypeptide folding occurs immediately with the assistance of both ribosome-associated and free chaperones. While many chaperones known to date are dedicated folding catalysts, recent studies have revealed a novel chaperoning system that functions at the interface of protein biogenesis and quality control by using a special "holdase" activity in order to sort and channel client proteins to distinct destinations. The key component, Bag6/Bat3/Scythe, can effectively shield long hydrophobic segments exposed on the surface of a polypeptide, preventing aggregation or inappropriate interactions before a triaging decision is made. The biological consequences of Bag6-mediated chaperoning are divergent for different substrates, ranging from membrane integration to proteasome targeting and destruction. Accordingly, Bag6 can act in various cellular contexts in order to execute many essential cellular functions, while dysfunctions in the Bag6 system can cause severe cellular abnormalities that may be associated with some pathological conditions.
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Affiliation(s)
- Jin-Gu Lee
- Laboratory of Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, USA
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15
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Kawahara H, Minami R, Yokota N. BAG6/BAT3: emerging roles in quality control for nascent polypeptides. J Biochem 2012; 153:147-60. [PMID: 23275523 DOI: 10.1093/jb/mvs149] [Citation(s) in RCA: 68] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
BAG6 (also known as BAT3/Scythe) is a ubiquitin-like protein that is thought to participate in a variety of seemingly unrelated physiological and pathological processes, such as apoptosis, antigen presentation and the T-cell response. Recent studies have shown that BAG6 is essential for the quality control of aggregation-prone polypeptide biogenesis. It forms part of a complex that determines the fate of newly synthesized client proteins for membrane insertion, ubiquitin-mediated degradation and/or aggregate formation. A biologically relevant transmembrane protein family has recently been shown to be a major client of BAG6, suggesting that many of the known diverse BAG6 functions can be interpreted by BAG6-mediated control of membrane protein biogenesis. In this review, we summarize the current understanding of the physiological roles of BAG6 with a particular focus on quality control for nascent chain polypeptides.
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Affiliation(s)
- Hiroyuki Kawahara
- Department of Biological Sciences, Laboratory of Cell Biology and Biochemistry, Tokyo Metropolitan University, Tokyo, Japan.
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16
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TIAN YE, WAN HAN, TAN GUANG. Cell cycle-related kinase in carcinogenesis. Oncol Lett 2012; 4:601-606. [PMID: 23205069 PMCID: PMC3506610 DOI: 10.3892/ol.2012.828] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2012] [Accepted: 07/24/2012] [Indexed: 12/16/2022] Open
Abstract
Cell cycle-related kinase (CCRK) is a novel protein kinase homologous to both cyclin-dependent kinase 7 (Cdk7) and Cak1p groups of CDK-activating kinase (CAK). CCRK activates Cdk2, which controls the cell-cycle progression by phosphorylating a threonine residue conserved in Cdk2. Previous studies have indicated that the CCRK protein levels were elevated by more than 1.5-fold in tumor tissue, and that the overexpression of CCRK is associated with poor prognosis of the patients. Moreover, recent studies have shown that CCRK is involved in the Wnt signaling pathway associated with the genesis and evolution of cancer. This review aims to systematically present the information currently available on CCRK obtained from in vitro and in vivo studies and highlight its significance to tumorigenesis.
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Affiliation(s)
- YE TIAN
- Department of General Surgery, First Affiliated Hospital, Dalian Medical University, Dalian, Liaoning 116011,
P.R. China
| | - HAN WAN
- Department of General Surgery, First Affiliated Hospital, Dalian Medical University, Dalian, Liaoning 116011,
P.R. China
| | - GUANG TAN
- Department of General Surgery, First Affiliated Hospital, Dalian Medical University, Dalian, Liaoning 116011,
P.R. China
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17
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Grover A, Izzo AA. BAT3 regulates Mycobacterium tuberculosis protein ESAT-6-mediated apoptosis of macrophages. PLoS One 2012; 7:e40836. [PMID: 22808273 PMCID: PMC3396635 DOI: 10.1371/journal.pone.0040836] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2011] [Accepted: 06/15/2012] [Indexed: 01/08/2023] Open
Abstract
HLA-B-associated transcript 3 (BAT3), also known as Scythe or BAG6, is a nuclear protein implicated in the control of apoptosis and natural killer (NK) cell-dendritic cell (DC) interaction. We demonstrate that BAT3 modulates the immune response by regulating the function of macrophages. BAT3 is released by macrophages in vitro and it down-regulates nitric oxide and proinflammatory cytokines release in IFN-γ and LPS stimulated macrophages. Furthermore, Mycobacterium tuberculosis-derived protein ESAT-6 (Rv3875) induced transient increase in the expression and release of BAT3 in macrophages. We show that induction of apoptosis by ESAT-6 is dependent on the cleavage of BAT3 by caspase-3 and proteasomal degradation. Our results also indicate that BAT3 regulates ESAT-6-induced apoptosis by interacting with anti-apoptotic protein BCL-2. Taken together, the data suggest that BAT3 plays a role in the early immune response to M. tuberculosis infection and may be a key protein associated with the fate of antigen presenting cells during infection.
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Affiliation(s)
- Ajay Grover
- Departments of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, Colorado, United States of America.
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18
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Wu W, Song W, Li S, Ouyang S, Fok KL, Diao R, Miao S, Chan HC, Wang L. Regulation of apoptosis by Bat3-enhanced YWK-II/APLP2 protein stability. J Cell Sci 2012; 125:4219-29. [PMID: 22641691 DOI: 10.1242/jcs.086553] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
YWK-II protein/APLP2 is a member of an evolutionarily conserved protein family that includes amyloid precursor protein (APP) and amyloid precursor-like protein-1 (APLP1). We have previously demonstrated that YWK-II/APLP2 functions as a novel G(0)-protein-coupled receptor for Müllerian inhibiting substance (MIS) in cell survival. However, factors regulating the stability and turnover of YWK-II/APLP2 have not been identified. Here we present evidence that human leukocyte antigen-B-associated transcript 3 (Bat3), an important regulator involved in apoptosis, can interact with YWK-II/APLP2 and enhance its stability by reducing its ubiquitylation and degradation by the ubiquitin-proteasome system. Coexpression of different Bat3 domain deletion constructs with YWK-II/APLP2 reveals that the proline-rich domain of Bat3 is required for its binding to YWK-II/APLP2. In addition, we find that the protein levels of YWK-II/APLP2 could be enhanced by nuclear export of Bat3 under apoptotic stimulation. We also find elevated levels of Bat3 and YWK-II/APLP2 in human colorectal cancer with a positive correlation between the two. Taken together, these results have revealed a previously undefined mechanism regulating cell apoptosis and suggest that aberrant enhancement of YWK-II/APLP2 by nuclear export of Bat3 may play a role in cancer development by inhibiting cell apoptosis.
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Affiliation(s)
- Wei Wu
- State Key Laboratory of Medical Molecular Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences, Peking Union Medical College, Tsinghua University 5 Dong Dan San Tiao, Beijing 100005, China
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19
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Kämper N, Kessler J, Temme S, Wegscheid C, Winkler J, Koch N. A novel BAT3 sequence generated by alternative RNA splicing of exon 11B displays cell type-specific expression and impacts on subcellular localization. PLoS One 2012; 7:e35972. [PMID: 22558287 PMCID: PMC3338477 DOI: 10.1371/journal.pone.0035972] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2012] [Accepted: 03/24/2012] [Indexed: 01/24/2023] Open
Abstract
Background The human lymphocyte antigen (HLA) encoded BAT3/BAG6 recently attracted interest as a regulator of protein targeting and degradation, a function that could be exerted in the cytosol and in the nucleus. The BAT3 gene was described to consist of 25 exons. Diversity of transcripts can be generated by alternative RNA splicing, which may control subcellular distribution of BAT3. Methodology/Principal Findings By cDNA sequencing we identified a novel alternatively spliced sequence of the BAT3 gene located between exons 11 and 12, which was designated as exon 11B. Using PCR and colony hybridization we identified six cDNA variants, which were produced by RNA splicing of BAT3 exons 5, 11B and 24. In four examined cell types the content of BAT3 splice variants was examined. Most of the cDNA clones from monocyte-derived dendritic cells contain exon 11B, whereas this sequence was almost absent in the B lymphoma Raji. Exon 5 was detected in most and exon 24 in approximately half of the cDNA clones. The subcellular distribution of endogenous BAT3 largely correlates with a cell type specific splicing pattern. In cells transfected with BAT3 variants, full-length and Δ24 BAT3 displayed nearly exclusive nuclear staining, whereas variants deleted of exon 11B showed substantial cytosolic expression. We show here that BAT3 is mainly expressed in the cytosol of Raji cells, while other cell types displayed both cytosolic and nuclear staining. Export of BAT3 from the nucleus to the cytosol is inhibited by treatment with leptomycin B, indicating that the Crm1 pathway is involved. Nuclear expression of BAT3 containing exon 11B suggests that this sequence plays a role for nuclear retention of the protein. Conclusions/Significance Cell type-specific subcellular expression of BAT3 suggests distinct functions in the cytosol and in the nucleus. Differential expression of BAT3 variants may reconcile the multiple roles described for BAT3.
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Affiliation(s)
- Nadine Kämper
- Division of Immunobiology, Institute of Genetics, University of Bonn, Bonn, Germany.
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20
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Kämper N, Franken S, Temme S, Koch S, Bieber T, Koch N. γ-Interferon-regulated chaperone governs human lymphocyte antigen class II expression. FASEB J 2011; 26:104-16. [PMID: 21940994 DOI: 10.1096/fj.11-189670] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Antigen presentation by human lymphocyte antigen (HLA) class II peptide receptors alerts the immune system to infections. In antigen-presenting cells (APCs), HLA class II, HLA-DM, and associated invariant chain-encoding genes are exclusively regulated by the interferon γ (IFNγ)-inducible class II transactivator (CIITA). Control of CIITA expression could therefore govern expression of class II peptide receptors in the diverse group of APCs. We discovered that elevation of the HLA class III region encoded B-associated transcript 3 (BAT3) increases and depletion of BAT3 decreases expression of HLA class II, HLA-DM, and invariant chain. IFNγ strongly elevates BAT3 transcription in various tumor cell lines and in primary macrophages. BAT3 chaperones the simultaneously IFNγ-induced CIITA. Following IFNγ-treatment, both CIITA and BAT3 translocate from the cytosol to the nucleus. The nuclear import of CIITA mediated by IFNγ controls activation of HLA class II genes. BAT3 is a novel key regulator of components of the HLA class II processing pathway. We present a mechanism explaining how parallel IFNγ-mediated regulation of CIITA and of its chaperone BAT3 controls the level of components of the HLA class II processing pathway.
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Affiliation(s)
- Nadine Kämper
- Institute of Genetics, University of Bonn, Bonn, Germany
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21
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Kaczmarek K, Studencka M, Meinhardt A, Wieczerzak K, Thoms S, Engel W, Grzmil P. Overexpression of peroxisomal testis-specific 1 protein induces germ cell apoptosis and leads to infertility in male mice. Mol Biol Cell 2011; 22:1766-79. [PMID: 21460186 PMCID: PMC3093327 DOI: 10.1091/mbc.e09-12-0993] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Peroxisomal testis-specific 1 gene (Pxt1) is the only male germ cell-specific gene that encodes a peroxisomal protein known to date. To elucidate the role of Pxt1 in spermatogenesis, we generated transgenic mice expressing a c-MYC-PXT1 fusion protein under the control of the PGK2 promoter. Overexpression of Pxt1 resulted in induction of male germ cells' apoptosis mainly in primary spermatocytes, finally leading to male infertility. This prompted us to analyze the proapoptotic character of mouse PXT1, which harbors a BH3-like domain in the N-terminal part. In different cell lines, the overexpression of PXT1 also resulted in a dramatic increase of apoptosis, whereas the deletion of the BH3-like domain significantly reduced cell death events, thereby confirming that the domain is functional and essential for the proapoptotic activity of PXT1. Moreover, we demonstrated that PXT1 interacts with apoptosis regulator BAT3, which, if overexpressed, can protect cells from the PXT1-induced apoptosis. The PXT1-BAT3 association leads to PXT1 relocation from the cytoplasm to the nucleus. In summary, we demonstrated that PXT1 induces apoptosis via the BH3-like domain and that this process is inhibited by BAT3.
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Affiliation(s)
- Karina Kaczmarek
- Institute of Human Genetics, Georg-August-University of Göttingen, 37073 Göttingen, Germany
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Minami R, Hayakawa A, Kagawa H, Yanagi Y, Yokosawa H, Kawahara H. BAG-6 is essential for selective elimination of defective proteasomal substrates. ACTA ACUST UNITED AC 2010; 190:637-50. [PMID: 20713601 PMCID: PMC2928017 DOI: 10.1083/jcb.200908092] [Citation(s) in RCA: 111] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
BAG-6/Scythe/BAT3 is a ubiquitin-like protein that was originally reported to be the product of a novel gene located within the human major histocompatibility complex, although the mechanisms of its function remain largely obscure. Here, we demonstrate the involvement of BAG-6 in the degradation of a CL1 model defective protein substrate in mammalian cells. We show that BAG-6 is essential for not only model substrate degradation but also the ubiquitin-mediated metabolism of newly synthesized defective polypeptides. Furthermore, our in vivo and in vitro analysis shows that BAG-6 interacts physically with puromycin-labeled nascent chain polypeptides and regulates their proteasome-mediated degradation. Finally, we show that knockdown of BAG-6 results in the suppressed presentation of MHC class I on the cell surface, a procedure known to be affected by the efficiency of metabolism of defective ribosomal products. Therefore, we propose that BAG-6 is necessary for ubiquitin-mediated degradation of newly synthesized defective polypeptides.
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Affiliation(s)
- Ryosuke Minami
- Department of Biological Sciences, Tokyo Metropolitan University, Tokyo, Japan
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Sturgill TW, Stoddard PB, Cohn SM, Mayo MW. The promoter for intestinal cell kinase is head-to-head with F-Box 9 and contains functional sites for TCF7L2 and FOXA factors. Mol Cancer 2010; 9:104. [PMID: 20459822 PMCID: PMC2876993 DOI: 10.1186/1476-4598-9-104] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2009] [Accepted: 05/11/2010] [Indexed: 12/13/2022] Open
Abstract
Background Intestinal cell kinase (ICK; GeneID 22858) is a conserved MAPK and CDK-like kinase that is widely expressed in human tissues. Data from the Cancer Genome Anatomy Project indicated ICK mRNA is increased in cancer, and that its expression correlated with expression of mRNA for an uncharacterized F-box protein, FBX9 (GeneID: 26268). ICK and FBX9 genes are arranged head-to-head on opposite strands, with start sites for transcription separated by ~3.3 kb. We hypothesized ICK and FBX9 are potentially important genes in cancer controlled by a bidirectional promoter. Results We assessed promoter activity of the intergenic region in both orientations in cancer cell lines derived from breast (AU565, SKBR3), colon (HCT-15, KM12), and stomach (AGS) cancers, as well as in embryonic human kidney (HEK293T) cells. The intergenic segment was active in both orientations in all of these lines, and ICK promoter activity was greater than FBX9 promoter activity. Results from deletions and truncations defined a minimal promoter for ICK, and revealed that repressors and enhancers differentially regulate ICK versus FBX9 promoter activity. The ICK promoter contains consensus motifs for several FOX-family transcription factors that align when mouse and human are compared using EMBOSS. FOXA1 and FOXA2 increase luciferase activity of a minimal promoter 10-20 fold in HEK293T cells. Consensus sites for TCF7L2 (TCF4) (Gene Id: 6934) are also present in both mouse and human. The expression of β-catenin increased activity of the minimal promoter ~10 fold. ICK reference mRNAs (NM_014920.3, NM_016513) are expressed in low copy number and increased in some breast cancers, using a ten base tag 5'-TCAACCTTAT-3' specific for both ICK transcripts. Conclusion ICK and FBX9 are divergently transcribed from a bidirectional promoter that is GC-rich and contains a CpG island. A minimal promoter for ICK contains functional sites for β-cateinin/TCF7L2 and FOXA. These data are consistent with functions that have been proposed for ICK in development and in proliferation or survival of some breast and colon cancers.
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Affiliation(s)
- Thomas W Sturgill
- Departments of Pharmacology and Internal Medicine, University of Virginia, 1300 Jefferson Park Avenue, Charlottesville, Virginia 22908, USA.
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Lata C, Sahu PP, Prasad M. Comparative transcriptome analysis of differentially expressed genes in foxtail millet (Setaria italica L.) during dehydration stress. Biochem Biophys Res Commun 2010; 393:720-7. [PMID: 20171162 DOI: 10.1016/j.bbrc.2010.02.068] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2010] [Accepted: 02/10/2010] [Indexed: 11/26/2022]
Abstract
Dehydration stress is one of the most important abiotic stresses that adversely influence crop growth and productivity. With the aim to understand the molecular mechanisms underlying dehydration stress tolerance in foxtail millet (Setaria italica L.), a drought tolerant crop, we examined its transcriptome changes at two time points (early and late) of dehydration stress. Two suppression subtractive hybridization (SSH) forward libraries were constructed from 21-day old seedlings of tolerant cv. Prasad at 0.5 and 6h PEG-induced dehydration stress. A total of 327 unique ESTs were identified from both libraries and were classified into 11 different categories according to their putative functions. The plant response against dehydration stress was complex, representing major transcripts involved in metabolism, stress, signaling, transcription regulation, translation and proteolysis. By Reverse Northern (RN) technique we identified the differential expression pattern of 327 transcripts, 86 (about 26%) of which showed > or = 1.7-fold induction. Further the obtained results were validated by quantitative real-time PCR (qRT-PCR) to have a comparative expression profiling of randomly chosen 9 up-regulated transcripts (> or =2.5 fold induction) between cv. Prasad (tolerant) and cv. Lepakshi (sensitive) upon dehydration stress. These transcripts showed a differential expression pattern in both cultivars at different time points of stress treatment as analyzed by qRT-PCR. The possible relationship of the identified transcripts with dehydration tolerance mechanism is discussed.
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Affiliation(s)
- Charu Lata
- National Institute of Plant Genome Research, Aruna Asaf Ali Marg, New Delhi 110 067, India
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Tsukahara T, Kimura S, Ichimiya S, Torigoe T, Kawaguchi S, Wada T, Yamashita T, Sato N. Scythe/BAT3 regulates apoptotic cell death induced by papillomavirus binding factor in human osteosarcoma. Cancer Sci 2009; 100:47-53. [PMID: 19018758 PMCID: PMC11158922 DOI: 10.1111/j.1349-7006.2008.00991.x] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2008] [Revised: 08/27/2008] [Accepted: 09/04/2008] [Indexed: 12/01/2022] Open
Abstract
Papillomavirus binding factor (PBF) was first identified as a transcription factor regulating the promoter activity of human papillomavirus. We previously demonstrated that PBF is an osteosarcoma-associated antigen and 92% of osteosarcoma tissues express PBF in the nucleus. Moreover, PBF-positive osteosarcoma has a significantly poorer prognosis than that with negative expression of PBF. In the present study, we assessed the biological role of PBF in cell survival. Overexpression of PBF induced cell death-mediated lactate dehydrase (LDH) release from 293EBNA cells. Cleaved poly(ADP-ribose) polymerase and active caspase-3 were also detected. However, PBF-induced apoptosis did not affect caspase-9 activity. Next, to identify the apoptosis regulator of PBF, we screened a cDNA library constructed from mRNA of the osteosarcoma cell line OS2000 using a yeast two-hybrid system and isolated Scythe/BAT3. Scythe/BAT3 mRNA was detected in 56% of osteosarcoma tissues and ubiquitously in various normal tissues. Although Scythe/BAT3 was localized to the cytoplasm in normal tissue, it was localized to the nucleus in osteosarcoma tissue. PBF and Scythe/BAT3 also colocalized to the cytoplasm in 293T cells and the nucleus in OS2000. Furthermore, overexpression of Scythe/BAT3 suppressed cell death events that resulted from overexpression of PBF in OS2000, but not in 293EBNA cells. Thus, our results support the ideas that: (i) PBF could induce apoptotic cell death via a caspase-9-independent pathway; (ii) the apoptosis regulator Scythe/BAT3 is a PBF-associated molecule acting as a nucleus-cytoplasm shuttling protein; and (iii) colocalization of PBF and Scythe/BAT3 in the nucleus might be an important factor for survival of osteosarcoma cells.
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Affiliation(s)
- Tomohide Tsukahara
- Department of Pathology, Sapporo Medical University School of Medicine, South-1, West-17, Chuo-ku, Sapporo 060-8556, Japan.
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