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Tien JCY, Chang Y, Zhang Y, Chou J, Cheng Y, Wang X, Yang J, Mannan R, Shah P, Wang XM, Todd AJ, Eyunni S, Cheng C, Rebernick RJ, Xiao L, Bao Y, Neiswender J, Brough R, Pettitt SJ, Cao X, Miner SJ, Zhou L, Wu YM, Labanca E, Wang Y, Parolia A, Cieslik M, Robinson DR, Wang Z, Feng FY, Lord CJ, Ding K, Chinnaiyan AM. CDK12 Loss Promotes Prostate Cancer Development While Exposing Vulnerabilities to Paralog-Based Synthetic Lethality. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.03.20.585990. [PMID: 38562774 PMCID: PMC10983964 DOI: 10.1101/2024.03.20.585990] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/04/2024]
Abstract
Biallelic loss of cyclin-dependent kinase 12 (CDK12) defines a unique molecular subtype of metastatic castration-resistant prostate cancer (mCRPC). It remains unclear, however, whether CDK12 loss per se is sufficient to drive prostate cancer development-either alone, or in the context of other genetic alterations-and whether CDK12-mutant tumors exhibit sensitivity to specific pharmacotherapies. Here, we demonstrate that tissue-specific Cdk12 ablation is sufficient to induce preneoplastic lesions and robust T cell infiltration in the mouse prostate. Allograft-based CRISPR screening demonstrated that Cdk12 loss is positively associated with Trp53 inactivation but negatively associated with Pten inactivation-akin to what is observed in human mCRPC. Consistent with this, ablation of Cdk12 in prostate organoids with concurrent Trp53 loss promotes their proliferation and ability to form tumors in mice, while Cdk12 knockout in the Pten-null prostate cancer mouse model abrogates tumor growth. Bigenic Cdk12 and Trp53 loss allografts represent a new syngeneic model for the study of androgen receptor (AR)-positive, luminal prostate cancer. Notably, Cdk12/Trp53 loss prostate tumors are sensitive to immune checkpoint blockade. Cdk12-null organoids (either with or without Trp53 co-ablation) and patient-derived xenografts from tumors with CDK12 inactivation are highly sensitive to inhibition or degradation of its paralog kinase, CDK13. Together, these data identify CDK12 as a bona fide tumor suppressor gene with impact on tumor progression and lends support to paralog-based synthetic lethality as a promising strategy for treating CDK12-mutant mCRPC.
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Affiliation(s)
- Jean Ching-Yi Tien
- Michigan Center for Translational Pathology, University of Michigan, Ann Arbor, MI, USA
- Department of Pathology, University of Michigan, Ann Arbor, MI, USA
| | - Yu Chang
- Michigan Center for Translational Pathology, University of Michigan, Ann Arbor, MI, USA
- Department of Pathology, University of Michigan, Ann Arbor, MI, USA
- These authors contributed equally to this work
| | - Yuping Zhang
- Michigan Center for Translational Pathology, University of Michigan, Ann Arbor, MI, USA
- Department of Pathology, University of Michigan, Ann Arbor, MI, USA
- These authors contributed equally to this work
| | - Jonathan Chou
- Helen Diller Family Comprehensive Cancer Center, University of California, San Francisco, CA, USA
- Division of Hematology/Oncology, Department of Medicine, University of California, San Francisco, CA, USA
- These authors contributed equally to this work
| | - Yunhui Cheng
- Michigan Center for Translational Pathology, University of Michigan, Ann Arbor, MI, USA
- Department of Pathology, University of Michigan, Ann Arbor, MI, USA
- These authors contributed equally to this work
| | - Xiaoju Wang
- Michigan Center for Translational Pathology, University of Michigan, Ann Arbor, MI, USA
- Department of Pathology, University of Michigan, Ann Arbor, MI, USA
| | - Jianzhang Yang
- State Key Laboratory of Chemical Biology, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai 200032, People’s Republic of China
- International Cooperative Laboratory of Traditional Chinese Medicine Modernization and Innovative Drug Discovery of Chinese Ministry of Education (MOE), Guangzhou City Key Laboratory of Precision Chemical Drug Development, College of Pharmacy, Jinan University, Guangzhou 511400, People’s Republic of China
| | - Rahul Mannan
- Michigan Center for Translational Pathology, University of Michigan, Ann Arbor, MI, USA
- Department of Pathology, University of Michigan, Ann Arbor, MI, USA
| | - Palak Shah
- Michigan Center for Translational Pathology, University of Michigan, Ann Arbor, MI, USA
- Department of Pathology, University of Michigan, Ann Arbor, MI, USA
| | - Xiao-Ming Wang
- Michigan Center for Translational Pathology, University of Michigan, Ann Arbor, MI, USA
- Department of Pathology, University of Michigan, Ann Arbor, MI, USA
| | - Abigail J. Todd
- Michigan Center for Translational Pathology, University of Michigan, Ann Arbor, MI, USA
- Department of Pathology, University of Michigan, Ann Arbor, MI, USA
| | - Sanjana Eyunni
- Michigan Center for Translational Pathology, University of Michigan, Ann Arbor, MI, USA
- Department of Pathology, University of Michigan, Ann Arbor, MI, USA
| | - Caleb Cheng
- Michigan Center for Translational Pathology, University of Michigan, Ann Arbor, MI, USA
| | - Ryan J. Rebernick
- Michigan Center for Translational Pathology, University of Michigan, Ann Arbor, MI, USA
- Department of Pathology, University of Michigan, Ann Arbor, MI, USA
| | - Lanbo Xiao
- Michigan Center for Translational Pathology, University of Michigan, Ann Arbor, MI, USA
- Department of Pathology, University of Michigan, Ann Arbor, MI, USA
| | - Yi Bao
- Michigan Center for Translational Pathology, University of Michigan, Ann Arbor, MI, USA
- Department of Pathology, University of Michigan, Ann Arbor, MI, USA
| | - James Neiswender
- The CRUK Gene Function Laboratory and Breast Cancer Now Toby Robins Research Centre, The Institute of Cancer Research, London, SW3 6JB, UK
| | - Rachel Brough
- The CRUK Gene Function Laboratory and Breast Cancer Now Toby Robins Research Centre, The Institute of Cancer Research, London, SW3 6JB, UK
| | - Stephen J. Pettitt
- The CRUK Gene Function Laboratory and Breast Cancer Now Toby Robins Research Centre, The Institute of Cancer Research, London, SW3 6JB, UK
| | - Xuhong Cao
- Michigan Center for Translational Pathology, University of Michigan, Ann Arbor, MI, USA
- Department of Pathology, University of Michigan, Ann Arbor, MI, USA
| | - Stephanie J. Miner
- Michigan Center for Translational Pathology, University of Michigan, Ann Arbor, MI, USA
- Department of Pathology, University of Michigan, Ann Arbor, MI, USA
| | - Licheng Zhou
- State Key Laboratory of Chemical Biology, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai 200032, People’s Republic of China
- International Cooperative Laboratory of Traditional Chinese Medicine Modernization and Innovative Drug Discovery of Chinese Ministry of Education (MOE), Guangzhou City Key Laboratory of Precision Chemical Drug Development, College of Pharmacy, Jinan University, Guangzhou 511400, People’s Republic of China
| | - Yi-Mi Wu
- Michigan Center for Translational Pathology, University of Michigan, Ann Arbor, MI, USA
- Department of Pathology, University of Michigan, Ann Arbor, MI, USA
| | - Estefania Labanca
- Department of Genitourinary Medical Oncology and David H. Koch Center for Applied Research of Genitourinary Cancer, University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Yuzhuo Wang
- Vancouver Prostate Centre, Vancouver General Hospital and Department of Urologic Sciences, University of British Columbia, Vancouver, British Columbia, V6H 3Z6, Canada
| | - Abhijit Parolia
- Michigan Center for Translational Pathology, University of Michigan, Ann Arbor, MI, USA
- Department of Pathology, University of Michigan, Ann Arbor, MI, USA
- Rogel Cancer Center, University of Michigan, Ann Arbor, MI, USA
| | - Marcin Cieslik
- Michigan Center for Translational Pathology, University of Michigan, Ann Arbor, MI, USA
- Department of Pathology, University of Michigan, Ann Arbor, MI, USA
| | - Dan R. Robinson
- Michigan Center for Translational Pathology, University of Michigan, Ann Arbor, MI, USA
- Department of Pathology, University of Michigan, Ann Arbor, MI, USA
| | - Zhen Wang
- State Key Laboratory of Chemical Biology, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai 200032, People’s Republic of China
- International Cooperative Laboratory of Traditional Chinese Medicine Modernization and Innovative Drug Discovery of Chinese Ministry of Education (MOE), Guangzhou City Key Laboratory of Precision Chemical Drug Development, College of Pharmacy, Jinan University, Guangzhou 511400, People’s Republic of China
| | - Felix Y. Feng
- Helen Diller Family Comprehensive Cancer Center, University of California, San Francisco, CA, USA
- Division of Hematology/Oncology, Department of Medicine, University of California, San Francisco, CA, USA
- Departments of Radiation Oncology and Urology, University of California, San Francisco, CA, USA
| | - Christopher J. Lord
- The CRUK Gene Function Laboratory and Breast Cancer Now Toby Robins Research Centre, The Institute of Cancer Research, London, SW3 6JB, UK
| | - Ke Ding
- State Key Laboratory of Chemical Biology, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai 200032, People’s Republic of China
| | - Arul M. Chinnaiyan
- Michigan Center for Translational Pathology, University of Michigan, Ann Arbor, MI, USA
- Department of Pathology, University of Michigan, Ann Arbor, MI, USA
- Rogel Cancer Center, University of Michigan, Ann Arbor, MI, USA
- Department of Urology, University of Michigan, Ann Arbor, MI, USA
- Howard Hughes Medical Institute, University of Michigan, Ann Arbor, MI, USA
- Lead contact
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Wu W, Yu S, Yu X. Transcription-associated cyclin-dependent kinase 12 (CDK12) as a potential target for cancer therapy. Biochim Biophys Acta Rev Cancer 2023; 1878:188842. [PMID: 36460141 DOI: 10.1016/j.bbcan.2022.188842] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2022] [Revised: 11/24/2022] [Accepted: 11/25/2022] [Indexed: 12/05/2022]
Abstract
Cyclin-dependent kinase 12 (CDK12), a transcription-related cyclin dependent kinase (CDK), plays a momentous part in multitudinous biological functions, such as replication, transcription initiation to elongation and termination, precursor mRNA (pre-mRNA) splicing, intron polyadenylation (IPA), and translation. CDK12 can act as a tumour suppressor or oncogene in disparate cellular environments, and its dysregulation likely provokes tumorigenesis. A comprehensive understanding of CDK12 will tremendously facilitate the exploitation of novel tactics for the treatment and precaution of cancer. Currently, CDK12 inhibitors are nonspecific and nonselective, which profoundly hinders the pharmacological target validation and drug exploitation process. Herein, we summarize the newly comprehension of the biological functions of CDK12 with a focus on recently emerged advancements of CDK12-associated therapeutic approaches in cancers.
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Affiliation(s)
- Wence Wu
- Departments of Orthopedics, National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China; Department of Etiology and Carcinogenesis, National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China; State Key Laboratory of Molecular Oncology, National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China; Beijing Key Laboratory for Carcinogenesis and Cancer Prevention, National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Shengji Yu
- Departments of Orthopedics, National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China.
| | - Xiying Yu
- Department of Etiology and Carcinogenesis, National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China; State Key Laboratory of Molecular Oncology, National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China; Beijing Key Laboratory for Carcinogenesis and Cancer Prevention, National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China.
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3
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Lei P, Zhang J, Liao P, Ren C, Wang J, Wang Y. Current progress and novel strategies that target CDK12 for drug discovery. Eur J Med Chem 2022; 240:114603. [PMID: 35868123 DOI: 10.1016/j.ejmech.2022.114603] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2022] [Revised: 07/08/2022] [Accepted: 07/08/2022] [Indexed: 02/05/2023]
Abstract
CDK12 is a cyclin-dependent kinase that plays critical roles in DNA replication, transcription, mRNA splicing, and DNA damage repair. CDK12 genomic changes, including mutation, amplification, deletion, and fusion, lead to various cancers, such as colorectal cancer, gastric cancer, and ovarian cancer. An increasing number of CDK12 inhibitors have been reported since CDK12 was identified as a biomarker and cancer therapeutic target. A major challenge lies in that CDK12 and CDK13 share highly similar sequences, which leads to great difficulties in the development of highly selective CDK12 inhibitors. In recent years, great efforts were made in developing selective CDK12 blockers. Techniques including PROTAC and molecular glue degraders were also applied to facilitate their development. Also, the drug combination strategy of CDK12 small molecule inhibitors were studied. This review discusses the latest studies on CDK12 inhibitors and analyzes their structure-activity relationships, shedding light on their further development.
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Affiliation(s)
- Peng Lei
- Targeted Tracer Research and Development Laboratory, Institute of Respiratory Health, Frontiers Science Center for Disease-related Molecular Network, Joint Research Institution of Altitude Health, National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu, 610041, Sichuan, China; State Key Laboratory of Biotherapy and Cancer Center, Department of Respiratory and Critical Care Medicine, West China Hospital, Sichuan University, Chengdu, 610041, Sichuan, China
| | - Jifa Zhang
- Targeted Tracer Research and Development Laboratory, Institute of Respiratory Health, Frontiers Science Center for Disease-related Molecular Network, Joint Research Institution of Altitude Health, National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu, 610041, Sichuan, China; State Key Laboratory of Biotherapy and Cancer Center, Department of Respiratory and Critical Care Medicine, West China Hospital, Sichuan University, Chengdu, 610041, Sichuan, China; Tianfu Jincheng Laboratory, Chengdu, 610041, Sichuan, China
| | - Peiyu Liao
- School of Pharmacy, Chengdu Medical College, Chengdu, 610500, Sichuan, China
| | - Changyu Ren
- Department of Pharmacy, Chengdu Fifth People's Hospital, Chengdu, 611130, Sichuan, China
| | - Jiaxing Wang
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Tennessee Health Science Center, Memphis, 38163, Tennessee, United States
| | - Yuxi Wang
- Targeted Tracer Research and Development Laboratory, Institute of Respiratory Health, Frontiers Science Center for Disease-related Molecular Network, Joint Research Institution of Altitude Health, National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu, 610041, Sichuan, China; State Key Laboratory of Biotherapy and Cancer Center, Department of Respiratory and Critical Care Medicine, West China Hospital, Sichuan University, Chengdu, 610041, Sichuan, China; Tianfu Jincheng Laboratory, Chengdu, 610041, Sichuan, China.
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4
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Pogodalla N, Winkler B, Klämbt C. Glial Tiling in the Insect Nervous System. Front Cell Neurosci 2022; 16:825695. [PMID: 35250488 PMCID: PMC8891220 DOI: 10.3389/fncel.2022.825695] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Accepted: 01/06/2022] [Indexed: 11/30/2022] Open
Abstract
The Drosophila nervous system comprises a small number of well characterized glial cell classes. The outer surface of the central nervous system (CNS) is protected by a glial derived blood-brain barrier generated by perineurial and subperineurial glia. All neural stem cells and all neurons are engulfed by cortex glial cells. The inner neuropil region, that harbors all synapses and dendrites, is covered by ensheathing glia and infiltrated by astrocyte-like glial cells. All these glial cells show a tiled organization with an often remarkable plasticity where glial cells of one cell type invade the territory of the neighboring glial cell type upon its ablation. Here, we summarize the different glial tiling patterns and based on the different modes of cell-cell contacts we hypothesize that different molecular mechanisms underlie tiling of the different glial cell types.
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5
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McMullen E, Weiler A, Becker HM, Schirmeier S. Plasticity of Carbohydrate Transport at the Blood-Brain Barrier. Front Behav Neurosci 2021; 14:612430. [PMID: 33551766 PMCID: PMC7863721 DOI: 10.3389/fnbeh.2020.612430] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Accepted: 12/17/2020] [Indexed: 12/21/2022] Open
Abstract
Neuronal function is highly energy demanding, requiring efficient transport of nutrients into the central nervous system (CNS). Simultaneously the brain must be protected from the influx of unwanted solutes. Most of the energy is supplied from dietary sugars, delivered from circulation via the blood-brain barrier (BBB). Therefore, selective transporters are required to shuttle metabolites into the nervous system where they can be utilized. The Drosophila BBB is formed by perineural and subperineurial glial cells, which effectively separate the brain from the surrounding hemolymph, maintaining a constant microenvironment. We identified two previously unknown BBB transporters, MFS3 (Major Facilitator Superfamily Transporter 3), located in the perineurial glial cells, and Pippin, found in both the perineurial and subperineurial glial cells. Both transporters facilitate uptake of circulating trehalose and glucose into the BBB-forming glial cells. RNA interference-mediated knockdown of these transporters leads to pupal lethality. However, null mutants reach adulthood, although they do show reduced lifespan and activity. Here, we report that both carbohydrate transport efficiency and resulting lethality found upon loss of MFS3 or Pippin are rescued via compensatory upregulation of Tret1-1, another BBB carbohydrate transporter, in Mfs3 and pippin null mutants, while RNAi-mediated knockdown is not compensated for. This means that the compensatory mechanisms in place upon mRNA degradation following RNA interference can be vastly different from those resulting from a null mutation.
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Affiliation(s)
- Ellen McMullen
- Department of Biology, Institute of Zoology, Technische Universität Dresden, Dresden, Germany
| | - Astrid Weiler
- Department of Biology, Institute of Zoology, Technische Universität Dresden, Dresden, Germany
| | - Holger M. Becker
- Division of General Zoology, Department of Biology, University of Kaiserslautern, Kaiserslautern, Germany
| | - Stefanie Schirmeier
- Department of Biology, Institute of Zoology, Technische Universität Dresden, Dresden, Germany
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6
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CDK12: a potential therapeutic target in cancer. Drug Discov Today 2020; 25:2257-2267. [PMID: 33038524 DOI: 10.1016/j.drudis.2020.09.035] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2020] [Revised: 08/30/2020] [Accepted: 09/30/2020] [Indexed: 12/14/2022]
Abstract
Cyclin-dependent kinase (CDK) 12 engages in diversified biological functions, from transcription, post-transcriptional modification, cell cycle, and translation to cellular proliferation. Moreover, it regulates the expression of cancer-related genes involved in DNA damage response (DDR) and replication, which are responsible for maintaining genomic stability. CDK12 emerges as an oncogene or tumor suppressor in different cellular contexts, where its dysregulation results in tumorigenesis. Current CDK12 inhibitors are nonselective, which impedes the process of pharmacological target validation and drug development. Herein, we discuss the latest understanding of the biological roles of CDK12 in cancers and provide molecular analyses of CDK12 inhibitors to guide the rational design of selective inhibitors.
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Liang S, Hu L, Wu Z, Chen Z, Liu S, Xu X, Qian A. CDK12: A Potent Target and Biomarker for Human Cancer Therapy. Cells 2020; 9:E1483. [PMID: 32570740 PMCID: PMC7349380 DOI: 10.3390/cells9061483] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2020] [Revised: 06/07/2020] [Accepted: 06/10/2020] [Indexed: 01/01/2023] Open
Abstract
Cyclin-dependent kinases (CDKs) are a group of serine/threonine protein kinases and play crucial roles in various cellular processes by regulating cell cycle and gene transcription. Cyclin-dependent kinase 12 (CDK12) is an important transcription-associated CDK. It shows versatile roles in regulating gene transcription, RNA splicing, translation, DNA damage response (DDR), cell cycle progression and cell proliferation. Recently, increasing evidence demonstrates the important role of CDK12 in various human cancers, illustrating it as both a biomarker of cancer and a potential target for cancer therapy. Here, we summarize the current knowledge of CDK12, and review the research advances of CDK12's biological functions, especially its role in human cancers and as a potential target and biomarker for cancer therapy.
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Affiliation(s)
- Shujing Liang
- Laboratory for Bone Metabolism, Xi’an Key Laboratory of Special Medicine and Health Engineering, Northwestern Polytechnical University, Xi’an 710072, China; (S.L.); (L.H.); (Z.W.); (Z.C.); (S.L.); (X.X.)
- Key Laboratory for Space Biosciences and Biotechnology, Research Center for Special Medicine and Health Systems Engineering, Northwestern Polytechnical University, Xi’an 710072, China
- NPU-UAB Joint Laboratory for Bone Metabolism, School of Life Sciences, Northwestern Polytechnical University, Xi’an 710072, China
| | - Lifang Hu
- Laboratory for Bone Metabolism, Xi’an Key Laboratory of Special Medicine and Health Engineering, Northwestern Polytechnical University, Xi’an 710072, China; (S.L.); (L.H.); (Z.W.); (Z.C.); (S.L.); (X.X.)
- Key Laboratory for Space Biosciences and Biotechnology, Research Center for Special Medicine and Health Systems Engineering, Northwestern Polytechnical University, Xi’an 710072, China
- NPU-UAB Joint Laboratory for Bone Metabolism, School of Life Sciences, Northwestern Polytechnical University, Xi’an 710072, China
| | - Zixiang Wu
- Laboratory for Bone Metabolism, Xi’an Key Laboratory of Special Medicine and Health Engineering, Northwestern Polytechnical University, Xi’an 710072, China; (S.L.); (L.H.); (Z.W.); (Z.C.); (S.L.); (X.X.)
- Key Laboratory for Space Biosciences and Biotechnology, Research Center for Special Medicine and Health Systems Engineering, Northwestern Polytechnical University, Xi’an 710072, China
- NPU-UAB Joint Laboratory for Bone Metabolism, School of Life Sciences, Northwestern Polytechnical University, Xi’an 710072, China
| | - Zhihao Chen
- Laboratory for Bone Metabolism, Xi’an Key Laboratory of Special Medicine and Health Engineering, Northwestern Polytechnical University, Xi’an 710072, China; (S.L.); (L.H.); (Z.W.); (Z.C.); (S.L.); (X.X.)
- Key Laboratory for Space Biosciences and Biotechnology, Research Center for Special Medicine and Health Systems Engineering, Northwestern Polytechnical University, Xi’an 710072, China
- NPU-UAB Joint Laboratory for Bone Metabolism, School of Life Sciences, Northwestern Polytechnical University, Xi’an 710072, China
| | - Shuyu Liu
- Laboratory for Bone Metabolism, Xi’an Key Laboratory of Special Medicine and Health Engineering, Northwestern Polytechnical University, Xi’an 710072, China; (S.L.); (L.H.); (Z.W.); (Z.C.); (S.L.); (X.X.)
- Key Laboratory for Space Biosciences and Biotechnology, Research Center for Special Medicine and Health Systems Engineering, Northwestern Polytechnical University, Xi’an 710072, China
- NPU-UAB Joint Laboratory for Bone Metabolism, School of Life Sciences, Northwestern Polytechnical University, Xi’an 710072, China
| | - Xia Xu
- Laboratory for Bone Metabolism, Xi’an Key Laboratory of Special Medicine and Health Engineering, Northwestern Polytechnical University, Xi’an 710072, China; (S.L.); (L.H.); (Z.W.); (Z.C.); (S.L.); (X.X.)
- Key Laboratory for Space Biosciences and Biotechnology, Research Center for Special Medicine and Health Systems Engineering, Northwestern Polytechnical University, Xi’an 710072, China
- NPU-UAB Joint Laboratory for Bone Metabolism, School of Life Sciences, Northwestern Polytechnical University, Xi’an 710072, China
| | - Airong Qian
- Laboratory for Bone Metabolism, Xi’an Key Laboratory of Special Medicine and Health Engineering, Northwestern Polytechnical University, Xi’an 710072, China; (S.L.); (L.H.); (Z.W.); (Z.C.); (S.L.); (X.X.)
- Key Laboratory for Space Biosciences and Biotechnology, Research Center for Special Medicine and Health Systems Engineering, Northwestern Polytechnical University, Xi’an 710072, China
- NPU-UAB Joint Laboratory for Bone Metabolism, School of Life Sciences, Northwestern Polytechnical University, Xi’an 710072, China
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Prieto-Sánchez S, Moreno-Castro C, Hernández-Munain C, Suñé C. Drosophila Prp40 localizes to the histone locus body and regulates gene transcription and development. J Cell Sci 2020; 133:jcs.239509. [PMID: 32094262 DOI: 10.1242/jcs.239509] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2019] [Accepted: 02/09/2020] [Indexed: 12/12/2022] Open
Abstract
In eukaryotes, a large amount of histones need to be synthesized during the S phase of the cell cycle to package newly synthesized DNA into chromatin. The transcription and 3' end processing of histone pre-mRNAs are controlled by the histone locus body (HLB), which is assembled on the shared promoter for H3 and H4 Here, we identified the Drosophila Prp40 pre-mRNA processing factor (dPrp40, annotated as CG3542) as a novel HLB component. We showed that dPrp40 is essential for Drosophila development, with functionally conserved activity in vertebrates and invertebrates. We observed that dPrp40 is fundamental in endocycling cells, highlighting a role for this factor in mediating replication efficiency in vivo The depletion of dPrp40 from fly cells inhibited the transcription, but not the 3' end processing, of histone mRNA in a H3- and H4-promoter-dependent manner. Our results establish that dPrp40 is an essential protein for Drosophila development that can localize to the HLB and might participate in histone mRNA biosynthesis.
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Affiliation(s)
- Silvia Prieto-Sánchez
- Department of Molecular Biology, Institute of Parasitology and Biomedicine "López-Neyra" (IPBLN-CSIC), PTS, 18016 Granada, Spain
| | - Cristina Moreno-Castro
- Department of Molecular Biology, Institute of Parasitology and Biomedicine "López-Neyra" (IPBLN-CSIC), PTS, 18016 Granada, Spain
| | - Cristina Hernández-Munain
- Department of Cell Biology and Immunology, Institute of Parasitology and Biomedicine "López-Neyra" (IPBLN-CSIC), PTS, 18016 Granada, Spain
| | - Carlos Suñé
- Department of Molecular Biology, Institute of Parasitology and Biomedicine "López-Neyra" (IPBLN-CSIC), PTS, 18016 Granada, Spain
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Pilarova K, Herudek J, Blazek D. CDK12: cellular functions and therapeutic potential of versatile player in cancer. NAR Cancer 2020; 2:zcaa003. [PMID: 34316683 PMCID: PMC8210036 DOI: 10.1093/narcan/zcaa003] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2020] [Revised: 02/14/2020] [Accepted: 02/20/2020] [Indexed: 12/16/2022] Open
Abstract
Cyclin-dependent kinase 12 (CDK12) phosphorylates the C-terminal domain of RNA polymerase II and is needed for the optimal transcription elongation and translation of a subset of human protein-coding genes. The kinase has a pleiotropic effect on the maintenance of genome stability, and its inactivation in prostate and ovarian tumours results in focal tandem duplications, a CDK12-unique genome instability phenotype. CDK12 aberrations were found in many other malignancies and have the potential to be used as biomarkers for therapeutic intervention. Moreover, the inhibition of CDK12 emerges as a promising strategy for treatment in several types of cancers. In this review, we summarize mechanisms that CDK12 utilizes for the regulation of gene expression and discuss how the perturbation of CDK12-sensitive genes contributes to the disruption of cell cycle progression and the onset of genome instability. Furthermore, we describe tumour-suppressive and oncogenic functions of CDK12 and its potential as a biomarker and inhibition target in anti-tumour treatments.
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Affiliation(s)
- Kveta Pilarova
- Central European Institute of Technology (CEITEC), Masaryk University, 62500 Brno, Czech Republic
| | - Jan Herudek
- Central European Institute of Technology (CEITEC), Masaryk University, 62500 Brno, Czech Republic
| | - Dalibor Blazek
- Central European Institute of Technology (CEITEC), Masaryk University, 62500 Brno, Czech Republic
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10
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Insights into the Involvement of Spliceosomal Mutations in Myelodysplastic Disorders from Analysis of SACY-1/DDX41 in Caenorhabditis elegans. Genetics 2020; 214:869-893. [PMID: 32060018 PMCID: PMC7153925 DOI: 10.1534/genetics.119.302973] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2019] [Accepted: 02/12/2020] [Indexed: 12/12/2022] Open
Abstract
Mutations affecting spliceosomal proteins are frequently found in hematological malignancies, including myelodysplastic syndromes and acute myeloid leukemia (AML). DDX41/Abstrakt is a metazoan-specific spliceosomal DEAD-box RNA helicase that is recurrently mutated in inherited myelodysplastic syndromes and in relapsing cases of AML. The genetic properties and genomic impacts of disease-causing missense mutations in DDX41 and other spliceosomal proteins have been uncertain. Here, we conduct a comprehensive analysis of the Caenorhabditis elegans DDX41 ortholog, SACY-1 Biochemical analyses defined SACY-1 as a component of the C. elegans spliceosome, and genetic analyses revealed synthetic lethal interactions with spliceosomal components. We used the auxin-inducible degradation system to analyze the consequence of SACY-1 depletion on the transcriptome using RNA sequencing. SACY-1 depletion impacts the transcriptome through splicing-dependent and splicing-independent mechanisms. Altered 3' splice site usage represents the predominant splicing defect observed upon SACY-1 depletion, consistent with a role for SACY-1 in the second step of splicing. Missplicing events appear more prevalent in the soma than the germline, suggesting that surveillance mechanisms protect the germline from aberrant splicing. The transcriptome changes observed after SACY-1 depletion suggest that disruption of the spliceosome induces a stress response, which could contribute to the cellular phenotypes conferred by sacy-1 mutant alleles. Multiple sacy-1 /ddx41 missense mutations, including the R525H human oncogenic variant, confer antimorphic activity, suggesting that their incorporation into the spliceosome is detrimental. Antagonistic variants that perturb the function of the spliceosome may be relevant to the disease-causing mutations, including DDX41, affecting highly conserved components of the spliceosome in humans.
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11
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CDK12 Activity-Dependent Phosphorylation Events in Human Cells. Biomolecules 2019; 9:biom9100634. [PMID: 31652541 PMCID: PMC6844070 DOI: 10.3390/biom9100634] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2019] [Revised: 10/16/2019] [Accepted: 10/17/2019] [Indexed: 12/15/2022] Open
Abstract
We asked whether the C-terminal repeat domain (CTD) kinase, CDK12/CyclinK, phosphorylates substrates in addition to the CTD of RPB1, using our CDK12analog-sensitive HeLa cell line to investigate CDK12 activity-dependent phosphorylation events in human cells. Characterizing the phospho-proteome before and after selective inhibition of CDK12 activity by the analog 1-NM-PP1, we identified 5,644 distinct phospho-peptides, among which were 50 whose average relative amount decreased more than 2-fold after 30 min of inhibition (none of these derived from RPB1). Half of the phospho-peptides actually showed >3-fold decreases, and a dozen showed decreases of 5-fold or more. As might be expected, the 40 proteins that gave rise to the 50 affected phospho-peptides mostly function in processes that have been linked to CDK12, such as transcription and RNA processing. However, the results also suggest roles for CDK12 in other events, notably mRNA nuclear export, cell differentiation and mitosis. While a number of the more-affected sites resemble the CTD in amino acid sequence and are likely direct CDK12 substrates, other highly-affected sites are not CTD-like, and their decreased phosphorylation may be a secondary (downstream) effect of CDK12 inhibition.
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12
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Neuert H, Deing P, Krukkert K, Naffin E, Steffes G, Risse B, Silies M, Klämbt C. The Drosophila NCAM homolog Fas2 signals independent of adhesion. Development 2019; 147:dev.181479. [DOI: 10.1242/dev.181479] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2019] [Accepted: 12/09/2019] [Indexed: 12/22/2022]
Abstract
The development of tissues and organs requires close interaction of cells. To do so, cells express adhesion proteins such as the neural cell adhesion molecule (NCAM) or its Drosophila orthologue Fasciclin 2 (Fas2). Both are members of the Ig-domain superfamily of proteins that mediate homophilic adhesion. These proteins are expressed as different isoforms differing in their membrane anchorage and their cytoplasmic domains. To study the function of single isoforms we have conducted a comprehensive genetic analysis of fas2. We reveal the expression pattern of all major Fas2 isoforms, two of which are GPI-anchored. The remaining five isoforms carry transmembrane domains with variable cytoplasmic tails. We generated fas2 mutants expressing only single isoforms. In contrast to the null mutation which causes embryonic lethality, these mutants are viable, indicating redundancy among the different isoforms. Cell type specific rescue experiments showed that glial secreted Fas2 can rescue the fas2 mutant phenotype to viability. This demonstrates cytoplasmic Fas2 domains have no apparent essential functions and indicate that Fas2 has function(s) other than homophilic adhesion. In conclusion, our data propose novel mechanistic aspects of a long studied adhesion protein.
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Affiliation(s)
- Helen Neuert
- University of Münster, Institute for Neuro- and Behavioral Biology, Badestr. 9, 48149 Münster, Germany
| | - Petra Deing
- University of Münster, Institute for Neuro- and Behavioral Biology, Badestr. 9, 48149 Münster, Germany
| | - Karin Krukkert
- University of Münster, Institute for Neuro- and Behavioral Biology, Badestr. 9, 48149 Münster, Germany
| | - Elke Naffin
- University of Münster, Institute for Neuro- and Behavioral Biology, Badestr. 9, 48149 Münster, Germany
| | - Georg Steffes
- University of Münster, Institute for Neuro- and Behavioral Biology, Badestr. 9, 48149 Münster, Germany
| | - Benjamin Risse
- University of Münster, Institute for Neuro- and Behavioral Biology, Badestr. 9, 48149 Münster, Germany
| | - Marion Silies
- University of Münster, Institute for Neuro- and Behavioral Biology, Badestr. 9, 48149 Münster, Germany
| | - Christian Klämbt
- University of Münster, Institute for Neuro- and Behavioral Biology, Badestr. 9, 48149 Münster, Germany
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13
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Babatz F, Naffin E, Klämbt C. The Drosophila Blood-Brain Barrier Adapts to Cell Growth by Unfolding of Pre-existing Septate Junctions. Dev Cell 2018; 47:697-710.e3. [PMID: 30482667 DOI: 10.1016/j.devcel.2018.10.002] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2018] [Revised: 08/07/2018] [Accepted: 10/01/2018] [Indexed: 12/18/2022]
Abstract
The blood-brain barrier is crucial for nervous system function. It is established early during development and stays intact during growth of the brain. In invertebrates, septate junctions are the occluding junctions of this barrier. Here, we used Drosophila to address how septate junctions grow during larval stages when brain size increases dramatically. We show that septate junctions are preassembled as long, highly folded strands during embryonic stages, connecting cell vertices. During subsequent cell growth, these corrugated strands are stretched out and stay intact during larval life with very little protein turnover. The G-protein coupled receptor Moody orchestrates the continuous organization of junctional strands in a process requiring F-actin. Consequently, in moody mutants, septate junction strands cannot properly stretch out during cell growth. To compensate for the loss of blood-brain barrier function, moody mutants form interdigitating cell-cell protrusions, resembling the evolutionary ancient barrier type found in primitive vertebrates or invertebrates such as cuttlefish.
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Affiliation(s)
- Felix Babatz
- University of Münster, Institute for Neuro and Behavioral Biology, Badestr. 9, 48149 Münster, Germany
| | - Elke Naffin
- University of Münster, Institute for Neuro and Behavioral Biology, Badestr. 9, 48149 Münster, Germany
| | - Christian Klämbt
- University of Münster, Institute for Neuro and Behavioral Biology, Badestr. 9, 48149 Münster, Germany.
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14
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The sulfite oxidase Shopper controls neuronal activity by regulating glutamate homeostasis in Drosophila ensheathing glia. Nat Commun 2018; 9:3514. [PMID: 30158546 PMCID: PMC6115356 DOI: 10.1038/s41467-018-05645-z] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2017] [Accepted: 07/13/2018] [Indexed: 01/01/2023] Open
Abstract
Specialized glial subtypes provide support to developing and functioning neural networks. Astrocytes modulate information processing by neurotransmitter recycling and release of neuromodulatory substances, whereas ensheathing glial cells have not been associated with neuromodulatory functions yet. To decipher a possible role of ensheathing glia in neuronal information processing, we screened for glial genes required in the Drosophila central nervous system for normal locomotor behavior. Shopper encodes a mitochondrial sulfite oxidase that is specifically required in ensheathing glia to regulate head bending and peristalsis. shopper mutants show elevated sulfite levels affecting the glutamate homeostasis which then act on neuronal network function. Interestingly, human patients lacking the Shopper homolog SUOX develop neurological symptoms, including seizures. Given an enhanced expression of SUOX by oligodendrocytes, our findings might indicate that in both invertebrates and vertebrates more than one glial cell type may be involved in modulating neuronal activity.
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15
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Zülbahar S, Sieglitz F, Kottmeier R, Altenhein B, Rumpf S, Klämbt C. Differential expression of Öbek controls ploidy in the Drosophila blood-brain barrier. Development 2018; 145:dev.164111. [PMID: 30002129 DOI: 10.1242/dev.164111] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2018] [Accepted: 07/03/2018] [Indexed: 12/13/2022]
Abstract
During development, tissue growth is mediated by either cell proliferation or cell growth, coupled with polyploidy. Both strategies are employed by the cell types that make up the Drosophila blood-brain barrier. During larval growth, the perineurial glia proliferate, whereas the subperineurial glia expand enormously and become polyploid. Here, we show that the level of ploidy in the subperineurial glia is controlled by the N-terminal asparagine amidohydrolase homolog Öbek, and high Öbek levels are required to limit replication. In contrast, perineurial glia express moderate levels of Öbek, and increased Öbek expression blocks their proliferation. Interestingly, other dividing cells are not affected by alteration of Öbek expression. In glia, Öbek counteracts fibroblast growth factor and Hippo signaling to differentially affect cell growth and number. We propose a mechanism by which growth signals are integrated differentially in a glia-specific manner through different levels of Öbek protein to adjust cell proliferation versus endoreplication in the blood-brain barrier.
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Affiliation(s)
- Selen Zülbahar
- Institute of Neurobiology, University of Münster, Badestrasse 9, 48149 Münster, Germany
| | - Florian Sieglitz
- Institute of Neurobiology, University of Münster, Badestrasse 9, 48149 Münster, Germany
| | - Rita Kottmeier
- Institute of Neurobiology, University of Münster, Badestrasse 9, 48149 Münster, Germany
| | - Benjamin Altenhein
- Institute of Zoology, University of Cologne, Zülpicher Straße 47b, 50674 Cologne, Germany
| | - Sebastian Rumpf
- Institute of Neurobiology, University of Münster, Badestrasse 9, 48149 Münster, Germany
| | - Christian Klämbt
- Institute of Neurobiology, University of Münster, Badestrasse 9, 48149 Münster, Germany
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16
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Jin Y, Dong H, Shi Y, Bian L. Mutually exclusive alternative splicing of pre-mRNAs. WILEY INTERDISCIPLINARY REVIEWS-RNA 2018; 9:e1468. [PMID: 29423937 DOI: 10.1002/wrna.1468] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/16/2017] [Revised: 12/20/2017] [Accepted: 12/20/2017] [Indexed: 12/14/2022]
Abstract
Pre-mRNA alternative splicing is an important mechanism used to expand protein diversity in higher eukaryotes, and mutually exclusive splicing is a specific type of alternative splicing in which only one of the exons in a cluster is included in functional transcripts. The most extraordinary example of this is the Drosophila melanogaster Down's syndrome cell adhesion molecule gene (Dscam), which potentially encodes 38,016 different isoforms through mutually exclusive splicing. Mutually exclusive splicing is a unique and challenging model that can be used to elucidate the evolution, regulatory mechanism, and function of alternative splicing. The use of new approaches has not only greatly expanded the mutually exclusive exome, but has also enabled the systematic analyses of single-cell alternative splicing during development. Furthermore, the identification of long-range RNA secondary structures provides a mechanistic framework for the regulation of mutually exclusive splicing (i.e., Dscam splicing). This article reviews recent insights into the identification, underlying mechanism, and roles of mutually exclusive splicing. This article is categorized under: RNA Processing > Splicing Regulation/Alternative Splicing RNA Structure and Dynamics > Influence of RNA Structure in Biological Systems.
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Affiliation(s)
- Yongfeng Jin
- Institute of Biochemistry, College of Life Sciences, Zhejiang University, Hangzhou, China
| | - Haiyang Dong
- Institute of Biochemistry, College of Life Sciences, Zhejiang University, Hangzhou, China
| | - Yang Shi
- Institute of Biochemistry, College of Life Sciences, Zhejiang University, Hangzhou, China
| | - Lina Bian
- Institute of Biochemistry, College of Life Sciences, Zhejiang University, Hangzhou, China
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17
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Tien JF, Mazloomian A, Cheng SWG, Hughes CS, Chow CCT, Canapi LT, Oloumi A, Trigo-Gonzalez G, Bashashati A, Xu J, Chang VCD, Shah SP, Aparicio S, Morin GB. CDK12 regulates alternative last exon mRNA splicing and promotes breast cancer cell invasion. Nucleic Acids Res 2017; 45:6698-6716. [PMID: 28334900 PMCID: PMC5499812 DOI: 10.1093/nar/gkx187] [Citation(s) in RCA: 105] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2016] [Accepted: 03/09/2017] [Indexed: 12/31/2022] Open
Abstract
CDK12 (cyclin-dependent kinase 12) is a regulatory kinase with evolutionarily conserved roles in modulating transcription elongation. Recent tumor genome studies of breast and ovarian cancers highlighted recurrent CDK12 mutations, which have been shown to disrupt DNA repair in cell-based assays. In breast cancers, CDK12 is also frequently co-amplified with the HER2 (ERBB2) oncogene. The mechanisms underlying functions of CDK12 in general and in cancer remain poorly defined. Based on global analysis of mRNA transcripts in normal and breast cancer cell lines with and without CDK12 amplification, we demonstrate that CDK12 primarily regulates alternative last exon (ALE) splicing, a specialized subtype of alternative mRNA splicing, that is both gene- and cell type-specific. These are unusual properties for spliceosome regulatory factors, which typically regulate multiple forms of alternative splicing in a global manner. In breast cancer cells, regulation by CDK12 modulates ALE splicing of the DNA damage response activator ATM and a DNAJB6 isoform that influences cell invasion and tumorigenesis in xenografts. We found that there is a direct correlation between CDK12 levels, DNAJB6 isoform levels and the migration capacity and invasiveness of breast tumor cells. This suggests that CDK12 gene amplification can contribute to the pathogenesis of the cancer.
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Affiliation(s)
- Jerry F Tien
- Canada's Michael Smith Genome Sciences Centre, BC Cancer Agency, Vancouver V5Z 1L3, Canada
| | - Alborz Mazloomian
- Graduate Bioinformatics Training Program, University of British Columbia, Vancouver V5Z 4S6, Canada.,Department of Molecular Oncology, BC Cancer Agency, Vancouver V5Z 1L3, Canada
| | - S-W Grace Cheng
- Canada's Michael Smith Genome Sciences Centre, BC Cancer Agency, Vancouver V5Z 1L3, Canada
| | - Christopher S Hughes
- Canada's Michael Smith Genome Sciences Centre, BC Cancer Agency, Vancouver V5Z 1L3, Canada
| | - Christalle C T Chow
- Canada's Michael Smith Genome Sciences Centre, BC Cancer Agency, Vancouver V5Z 1L3, Canada
| | - Leanna T Canapi
- Canada's Michael Smith Genome Sciences Centre, BC Cancer Agency, Vancouver V5Z 1L3, Canada
| | - Arusha Oloumi
- Department of Molecular Oncology, BC Cancer Agency, Vancouver V5Z 1L3, Canada
| | - Genny Trigo-Gonzalez
- Canada's Michael Smith Genome Sciences Centre, BC Cancer Agency, Vancouver V5Z 1L3, Canada
| | - Ali Bashashati
- Department of Molecular Oncology, BC Cancer Agency, Vancouver V5Z 1L3, Canada
| | - James Xu
- Department of Pathology and Laboratory Medicine, University of British Columbia, Vancouver V6T 2B5, Canada
| | - Vicky C-D Chang
- Canada's Michael Smith Genome Sciences Centre, BC Cancer Agency, Vancouver V5Z 1L3, Canada
| | - Sohrab P Shah
- Canada's Michael Smith Genome Sciences Centre, BC Cancer Agency, Vancouver V5Z 1L3, Canada.,Department of Molecular Oncology, BC Cancer Agency, Vancouver V5Z 1L3, Canada.,Department of Pathology and Laboratory Medicine, University of British Columbia, Vancouver V6T 2B5, Canada
| | - Samuel Aparicio
- Canada's Michael Smith Genome Sciences Centre, BC Cancer Agency, Vancouver V5Z 1L3, Canada.,Department of Molecular Oncology, BC Cancer Agency, Vancouver V5Z 1L3, Canada.,Department of Pathology and Laboratory Medicine, University of British Columbia, Vancouver V6T 2B5, Canada
| | - Gregg B Morin
- Canada's Michael Smith Genome Sciences Centre, BC Cancer Agency, Vancouver V5Z 1L3, Canada.,Department of Medical Genetics, University of British Columbia, Vancouver V6H 3N1, Canada
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18
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Paculová H, Kohoutek J. The emerging roles of CDK12 in tumorigenesis. Cell Div 2017; 12:7. [PMID: 29090014 PMCID: PMC5658942 DOI: 10.1186/s13008-017-0033-x] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2017] [Accepted: 10/16/2017] [Indexed: 12/25/2022] Open
Abstract
Cyclin-dependent kinases (CDKs) are key regulators of both cell cycle progression and transcription. Since dysregulation of CDKs is a frequently occurring event driving tumorigenesis, CDKs have been tested extensively as targets for cancer therapy. Cyclin-dependent kinase 12 (CDK12) is a transcription-associated kinase which participates in various cellular processes, including DNA damage response, development and cellular differentiation, as well as splicing and pre-mRNA processing. CDK12 mutations and amplification have been recently reported in different types of malignancies, including loss-of-function mutations in high-grade serous ovarian carcinomas, and that has led to assumption that CDK12 is a tumor suppressor. On the contrary, CDK12 overexpression in other tumors suggests the possibility that CDK12 has oncogenic properties, similarly to other transcription-associated kinases. In this review, we discuss current knowledge concerning the role of CDK12 in ovarian and breast tumorigenesis and the potential for chemical inhibitors of CDK12 in future cancer treatment.
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Affiliation(s)
- Hana Paculová
- Department of Chemistry and Toxicology, Veterinary Research Institute, Hudcova 296/70, Brno, 621 00 Czech Republic
| | - Jiří Kohoutek
- Department of Chemistry and Toxicology, Veterinary Research Institute, Hudcova 296/70, Brno, 621 00 Czech Republic
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19
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Chilà R, Guffanti F, Damia G. Role and therapeutic potential of CDK12 in human cancers. Cancer Treat Rev 2016; 50:83-88. [PMID: 27662623 DOI: 10.1016/j.ctrv.2016.09.003] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2016] [Revised: 08/30/2016] [Accepted: 09/01/2016] [Indexed: 12/31/2022]
Abstract
Phosphorylation of the RNA polymerase II C-terminal domain by cyclin-dependent kinases (CDKs) is important for productive transcription. Deregulated transcription-CDKs have been reported in different human cancers. Until recently CDK9 was the only transcription-CDK with a causative role in cancer, but evidence is cumulating of the importance of CDK12. This review summarizes the role of CDK12 in transcription and RNA processing, in maintaining genomic stability/integrity and in tumorigenesis. CDK12 mutations have been reported in many cancers and have been suggested as a cause of defective DNA repair in ovarian carcinoma. CDK12 may have a role as a new therapeutic target in oncology.
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Affiliation(s)
- Rosaria Chilà
- Laboratory of Molecular Pharmacology, Oncology Department, IRCCS - Istituto di Ricerche Farmacologiche Mario Negri, Milan, Italy
| | - Federica Guffanti
- Laboratory of Molecular Pharmacology, Oncology Department, IRCCS - Istituto di Ricerche Farmacologiche Mario Negri, Milan, Italy
| | - Giovanna Damia
- Laboratory of Molecular Pharmacology, Oncology Department, IRCCS - Istituto di Ricerche Farmacologiche Mario Negri, Milan, Italy.
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20
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Ladd AN. New Insights Into the Role of RNA-Binding Proteins in the Regulation of Heart Development. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2016; 324:125-85. [PMID: 27017008 DOI: 10.1016/bs.ircmb.2015.12.009] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The regulation of gene expression during development takes place both at the transcriptional and posttranscriptional levels. RNA-binding proteins (RBPs) regulate pre-mRNA processing, mRNA localization, stability, and translation. Many RBPs are expressed in the heart and have been implicated in heart development, function, or disease. This chapter will review the current knowledge about RBPs in the developing heart, focusing on those that regulate posttranscriptional gene expression. The involvement of RBPs at each stage of heart development will be considered in turn, including the establishment of specific cardiac cell types and formation of the primitive heart tube, cardiac morphogenesis, and postnatal maturation and aging. The contributions of RBPs to cardiac birth defects and heart disease will also be considered in these contexts. Finally, the interplay between RBPs and other regulatory factors in the developing heart, such as transcription factors and miRNAs, will be discussed.
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Affiliation(s)
- A N Ladd
- Department of Cellular and Molecular Medicine, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, United States of America.
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21
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Volkenhoff A, Weiler A, Letzel M, Stehling M, Klämbt C, Schirmeier S. Glial Glycolysis Is Essential for Neuronal Survival in Drosophila. Cell Metab 2015; 22:437-47. [PMID: 26235423 DOI: 10.1016/j.cmet.2015.07.006] [Citation(s) in RCA: 196] [Impact Index Per Article: 21.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/11/2015] [Revised: 05/19/2015] [Accepted: 06/02/2015] [Indexed: 12/14/2022]
Abstract
Neuronal information processing requires a large amount of energy, indicating that sugars and other metabolites must be efficiently delivered. However, reliable neuronal function also depends on the maintenance of a constant microenvironment in the brain. Therefore, neurons are efficiently separated from circulation by the blood-brain barrier, and their long axons are insulated by glial processes. At the example of the Drosophila brain, we addressed how sugar is shuttled across the barrier to nurture neurons. We show that glial cells of the blood-brain barrier specifically take up sugars and that their metabolism relies on glycolysis, which, surprisingly, is dispensable in neurons. Glial cells secrete alanine and lactate to fuel neuronal mitochondria, and lack of glial glycolysis specifically in the adult brain causes neurodegeneration. Our work implies that a global metabolic compartmentalization and coupling of neurons and glial cells is a conserved, fundamental feature of bilaterian nervous systems independent of their size.
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Affiliation(s)
- Anne Volkenhoff
- Institut für Neuro- und Verhaltensbiologie, Badestr. 9, 48149 Münster, Germany
| | - Astrid Weiler
- Institut für Neuro- und Verhaltensbiologie, Badestr. 9, 48149 Münster, Germany
| | - Matthias Letzel
- Organisch-Chemisches Institut der Universität Münster, Abt. Massenspektrometrie, Corrensstr. 40, 48149 Münster, Germany
| | - Martin Stehling
- MPI für molekulare Biomedizin, Röntgenstr. 20, 48149 Münster, Germany
| | - Christian Klämbt
- Institut für Neuro- und Verhaltensbiologie, Badestr. 9, 48149 Münster, Germany
| | - Stefanie Schirmeier
- Institut für Neuro- und Verhaltensbiologie, Badestr. 9, 48149 Münster, Germany.
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22
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Bartkowiak B, Yan C, Greenleaf AL. Engineering an analog-sensitive CDK12 cell line using CRISPR/Cas. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2015; 1849:1179-87. [PMID: 26189575 DOI: 10.1016/j.bbagrm.2015.07.010] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/21/2015] [Revised: 07/08/2015] [Accepted: 07/14/2015] [Indexed: 11/15/2022]
Abstract
The RNA Polymerase II C-terminal domain (CTD) kinase CDK12 has been implicated as a tumor suppressor and regulator of DNA damage response genes. Although much has been learned about CDK12 and its activity, due to the lack of a specific inhibitor and the complications posed by long term RNAi depletion, much is still unknown about the particulars of CDK12 function. Therefore gaining a better understanding of CDK12's roles at the molecular level will be challenging without the development of additional tools. In order to address these issues we have used the CRISPR/Cas gene engineering system to create a mammalian cell line in which the only functional copy of CDK12 is selectively inhibitable by a cell-permeable adenine analog (analog-sensitive CDK12). Inhibition of CDK12 results in a perturbation of the phosphorylation patterns on the CTD and an arrest in cellular proliferation. This cell line should serve as a powerful tool for future studies.
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Affiliation(s)
| | - Christopher Yan
- Department of Biochemistry, Duke University Medical Center, United States
| | - Arno L Greenleaf
- Department of Biochemistry, Duke University Medical Center, United States.
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23
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Sasse S, Neuert H, Klämbt C. Differentiation ofDrosophilaglial cells. WILEY INTERDISCIPLINARY REVIEWS-DEVELOPMENTAL BIOLOGY 2015; 4:623-36. [DOI: 10.1002/wdev.198] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/08/2014] [Revised: 03/25/2015] [Accepted: 05/24/2015] [Indexed: 01/10/2023]
Affiliation(s)
- Sofia Sasse
- Institut für Neuro- und Verhaltensbiologie; Münster Germany
| | - Helen Neuert
- Institut für Neuro- und Verhaltensbiologie; Münster Germany
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24
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Matzat T, Sieglitz F, Kottmeier R, Babatz F, Engelen D, Klämbt C. Axonal wrapping in the Drosophila PNS is controlled by glia-derived neuregulin homolog Vein. Development 2015; 142:1336-45. [PMID: 25758464 DOI: 10.1242/dev.116616] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Efficient neuronal conductance requires that axons are insulated by glial cells. For this, glial membranes need to wrap around axons. Invertebrates show a relatively simple extension of glial membranes around the axons, resembling Remak fibers formed by Schwann cells in the mammalian peripheral nervous system. To unravel the molecular pathways underlying differentiation of glial cells that provide axonal wrapping, we are using the genetically amenable Drosophila model. At the end of larval life, the wrapping glia differentiates into very large cells, spanning more than 1 mm of axonal length. The extension around axonal membranes is not influenced by the caliber of the axon or its modality. Using cell type-specific gene knockdown we show that the extension of glial membranes around the axons is regulated by an autocrine activation of the EGF receptor through the neuregulin homolog Vein. This resembles the molecular mechanism employed during cell-autonomous reactivation of glial differentiation after injury in mammals. We further demonstrate that Vein, produced by the wrapping glia, also regulates the formation of septate junctions in the abutting subperineurial glia. Moreover, the wrapping glia indirectly controls the proliferation of the perineurial glia. Thus, the wrapping glia appears center stage to orchestrate the development of the different glial cell layers in a peripheral nerve.
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Affiliation(s)
- Till Matzat
- Institut für Neurobiologie, Universität Münster, Badestr. 9, Münster D-48149, Germany
| | - Florian Sieglitz
- Institut für Neurobiologie, Universität Münster, Badestr. 9, Münster D-48149, Germany
| | - Rita Kottmeier
- Institut für Neurobiologie, Universität Münster, Badestr. 9, Münster D-48149, Germany
| | - Felix Babatz
- Institut für Neurobiologie, Universität Münster, Badestr. 9, Münster D-48149, Germany
| | - Daniel Engelen
- Institut für Neurobiologie, Universität Münster, Badestr. 9, Münster D-48149, Germany
| | - Christian Klämbt
- Institut für Neurobiologie, Universität Münster, Badestr. 9, Münster D-48149, Germany
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25
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Characterization of human cyclin-dependent kinase 12 (CDK12) and CDK13 complexes in C-terminal domain phosphorylation, gene transcription, and RNA processing. Mol Cell Biol 2015; 35:928-38. [PMID: 25561469 DOI: 10.1128/mcb.01426-14] [Citation(s) in RCA: 139] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Cyclin-dependent kinase 9 (CDK9) and CDK12 have each been demonstrated to phosphorylate the RNA polymerase II C-terminal domain (CTD) at serine 2 of the heptad repeat, both in vitro and in vivo. CDK9, as part of P-TEFb and the super elongation complex (SEC), is by far the best characterized of CDK9, CDK12, and CDK13. We employed both in vitro and in vivo assays to further investigate the molecular properties of CDK12 and its paralog CDK13. We isolated Flag-tagged CDK12 and CDK13 and found that they associate with numerous RNA processing factors. Although knockdown of CDK12, CDK13, or their cyclin partner CCNK did not affect the bulk CTD phosphorylation levels in HCT116 cells, transcriptome sequencing (RNA-seq) analysis revealed that CDK12 and CDK13 losses in HCT116 cells preferentially affect expression of DNA damage response and snoRNA genes, respectively. CDK12 and CDK13 depletion also leads to a loss of expression of RNA processing factors and to defects in RNA processing. These findings suggest that in addition to implementing CTD phosphorylation, CDK12 and CDK13 may affect RNA processing through direct physical interactions with RNA processing factors and by regulating their expression.
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26
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Hindle SJ, Bainton RJ. Barrier mechanisms in the Drosophila blood-brain barrier. Front Neurosci 2014; 8:414. [PMID: 25565944 PMCID: PMC4267209 DOI: 10.3389/fnins.2014.00414] [Citation(s) in RCA: 71] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2014] [Accepted: 11/24/2014] [Indexed: 12/12/2022] Open
Abstract
The invertebrate blood-brain barrier (BBB) field is growing at a rapid pace and, in recent years, studies have shown a physiologic and molecular complexity that has begun to rival its vertebrate counterpart. Novel mechanisms of paracellular barrier maintenance through G-protein coupled receptor signaling were the first demonstrations of the complex adaptive mechanisms of barrier physiology. Building upon this work, the integrity of the invertebrate BBB has recently been shown to require coordinated function of all layers of the compound barrier structure, analogous to signaling between the layers of the vertebrate neurovascular unit. These findings strengthen the notion that many BBB mechanisms are conserved between vertebrates and invertebrates, and suggest that novel findings in invertebrate model organisms will have a significant impact on the understanding of vertebrate BBB functions. In this vein, important roles in coordinating localized and systemic signaling to dictate organism development and growth are beginning to show how the BBB can govern whole animal physiologies. This includes novel functions of BBB gap junctions in orchestrating synchronized neuroblast proliferation, and of BBB secreted antagonists of insulin receptor signaling. These advancements and others are pushing the field forward in exciting new directions. In this review, we provide a synopsis of invertebrate BBB anatomy and physiology, with a focus on insights from the past 5 years, and highlight important areas for future study.
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Affiliation(s)
- Samantha J Hindle
- Department of Anesthesia and Perioperative Care, University of California, San Francisco San Francisco, CA, USA
| | - Roland J Bainton
- Department of Anesthesia and Perioperative Care, University of California, San Francisco San Francisco, CA, USA
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27
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Beadell AV, Haag ES. Evolutionary Dynamics of GLD-1-mRNA complexes in Caenorhabditis nematodes. Genome Biol Evol 2014; 7:314-35. [PMID: 25502909 PMCID: PMC4316625 DOI: 10.1093/gbe/evu272] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/04/2014] [Indexed: 12/17/2022] Open
Abstract
Given the large number of RNA-binding proteins and regulatory RNAs within genomes, posttranscriptional regulation may be an underappreciated aspect of cis-regulatory evolution. Here, we focus on nematode germ cells, which are known to rely heavily upon translational control to regulate meiosis and gametogenesis. GLD-1 belongs to the STAR-domain family of RNA-binding proteins, conserved throughout eukaryotes, and functions in Caenorhabditis elegans as a germline-specific translational repressor. A phylogenetic analysis across opisthokonts shows that GLD-1 is most closely related to Drosophila How and deuterostome Quaking, both implicated in alternative splicing. We identify messenger RNAs associated with C. briggsae GLD-1 on a genome-wide scale and provide evidence that many participate in aspects of germline development. By comparing our results with published C. elegans GLD-1 targets, we detect nearly 100 that are conserved between the two species. We also detected several hundred Cbr-GLD-1 targets whose homologs have not been reported to be associated with C. elegans GLD-1 in either of two independent studies. Low expression in C. elegans may explain the failure to detect most of them, but a highly expressed subset are strong candidates for Cbr-GLD-1-specific targets. We examine GLD-1-binding motifs among targets conserved in C. elegans and C. briggsae and find that most, but not all, display evidence of shared ancestral binding sites. Our work illustrates both the conservative and the dynamic character of evolution at the posttranslational level of gene regulation, even between congeners.
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Affiliation(s)
- Alana V Beadell
- Program in Behavior, Evolution, Ecology, and Systematics, University of Maryland, College Park Present address: Department of Organismal Biology and Anatomy, University of Chicago, Chicago, IL
| | - Eric S Haag
- Program in Behavior, Evolution, Ecology, and Systematics, University of Maryland, College Park Department of Biology, University of Maryland, College Park
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28
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Abstract
Post-transcriptional pre-mRNA splicing has emerged as a critical step in the gene expression cascade greatly influencing diversification and spatiotemporal control of the proteome in many developmental processes. The percentage of genes targeted by alternative splicing (AS) is shown to be over 95% in humans and 60% in Drosophila. Therefore, it is evident that deregulation of this process underlies many genetic diseases. Among all tissues, the brain shows the highest transcriptome diversity, which is not surprising in view of the complex inter- and intracellular networks underlying the development of this organ. Reports of isoforms known to function at different steps during Drosophila nervous system development are rapidly increasing as well as knowledge on their regulation and function, highlighting the role of AS during neuronal development in Drosophila.
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Affiliation(s)
- Carmen Mohr
- Institute of Human Genetics, University Medical Center Freiburg , Freiburg , Germany
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29
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Chen HR, Lin GT, Huang CK, Fann MJ. Cdk12 and Cdk13 regulate axonal elongation through a common signaling pathway that modulates Cdk5 expression. Exp Neurol 2014; 261:10-21. [PMID: 24999027 DOI: 10.1016/j.expneurol.2014.06.024] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2014] [Revised: 06/16/2014] [Accepted: 06/18/2014] [Indexed: 11/17/2022]
Abstract
Cdk12 and Cdk13 are Cdc2-related proteins that share 92% identity in their kinase domains. Using in situ hybridization and Western blot analysis, we detected the expression of Cdk12 and Cdk13 mRNAs and their proteins in developing mouse embryos, especially during development of the nervous system. We explored the roles of Cdk12 and Cdk13 in neuronal differentiation using the P19 neuronal differentiation model. Upon knockdown of Cdk12 or Cdk13, no effect on differentiated cell numbers was detected, but a substantial decrease of numbers of neurons with long neurites was identified. Similarly, knockdown of Cdk12 or Cdk13 in primarily cultured cortical neurons shortens the averaged axonal length. A microarray analysis was used to examine changes in gene expression after knockdown or overexpression of Cdk12 and we identified Cdk5 as a molecule potentially involved in mediating the effect of Cdk12 and Cdk13. Depletion of Cdk12 or Cdk13 in P19 cells significantly reduces Cdk5 expression at both the mRNA and protein levels. Expression of Cdk5 protein in the developing mouse brain is also reduced in conditional Cdk12-knockout mice in proportion to the residual amount of Cdk12 protein present. This suggests that the reduced axonal outgrowth after knockdown of Cdk12 or Cdk13 might be due to lower Cdk5 expression. Furthermore, overexpression of Cdk5 protein in P19 cells was able to partially rescue the neurite outgrowth defect observed when Cdk12 or Cdk13 is depleted. Together, these findings suggest that Cdk12 and Cdk13 regulate axonal elongation through a common signaling pathway that modulates Cdk5 expression.
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Affiliation(s)
- Hong-Ru Chen
- Department of Life Sciences and Institute of Genome Sciences, National Yang-Ming University, Taipei 11221, Taiwan, ROC
| | - Guan-Ting Lin
- Institute of Neuroscience, National Yang-Ming University, Taipei 11221, Taiwan, ROC
| | - Chun-Kai Huang
- Department of Life Sciences and Institute of Genome Sciences, National Yang-Ming University, Taipei 11221, Taiwan, ROC
| | - Ming-Ji Fann
- Department of Life Sciences and Institute of Genome Sciences, National Yang-Ming University, Taipei 11221, Taiwan, ROC; Brain Research Center, National Yang-Ming University, Taipei 11221, Taiwan, ROC.
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30
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Giuliani G, Giuliani F, Volk T, Rabouille C. The Drosophila RNA-binding protein HOW controls the stability of dgrasp mRNA in the follicular epithelium. Nucleic Acids Res 2014; 42:1970-86. [PMID: 24217913 PMCID: PMC3919595 DOI: 10.1093/nar/gkt1118] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2013] [Revised: 10/18/2013] [Accepted: 10/22/2013] [Indexed: 11/14/2022] Open
Abstract
Post-transcriptional regulation of RNA stability and localization underlies a wide array of developmental processes, such as axon guidance and epithelial morphogenesis. In Drosophila, ectopic expression of the classically Golgi peripheral protein dGRASP at the plasma membrane is achieved through its mRNA targeting at key developmental time-points, in a process critical to follicular epithelium integrity. However, the trans-acting factors that tightly regulate the spatio-temporal dynamics of dgrasp are unknown. Using an in silico approach, we identified two putative HOW Response Elements (HRE1 and HRE2) within the dgrasp open reading frame for binding to Held Out Wings (HOW), a member of the Signal Transduction and Activation of RNA family of RNA-binding proteins. Using RNA immunoprecipitations, we confirmed this by showing that the short cytoplasmic isoform of HOW binds directly to dgrasp HRE1. Furthermore, HOW loss of function in vivo leads to a significant decrease in dgrasp mRNA levels. We demonstrate that HRE1 protects dgrasp mRNA from cytoplasmic degradation, but does not mediate its targeting. We propose that this binding event promotes the formation of ribonucleoprotein particles that ensure dgrasp stability during transport to the basal plasma membrane, thus enabling the local translation of dgrasp for its roles at non-Golgi locations.
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Affiliation(s)
- Giuliano Giuliani
- Hubrecht Institute-KNAW & University Medical Center Utrecht, Uppsalalaan 8, 3584 CT Utrecht, The Netherlands, Department of Molecular Genetics, Weizmann Institute of Science, Rehovot 76100, Israel and The Department of Cell Biology, UMC Utrecht, The Netherlands
| | - Fabrizio Giuliani
- Hubrecht Institute-KNAW & University Medical Center Utrecht, Uppsalalaan 8, 3584 CT Utrecht, The Netherlands, Department of Molecular Genetics, Weizmann Institute of Science, Rehovot 76100, Israel and The Department of Cell Biology, UMC Utrecht, The Netherlands
| | - Talila Volk
- Hubrecht Institute-KNAW & University Medical Center Utrecht, Uppsalalaan 8, 3584 CT Utrecht, The Netherlands, Department of Molecular Genetics, Weizmann Institute of Science, Rehovot 76100, Israel and The Department of Cell Biology, UMC Utrecht, The Netherlands
| | - Catherine Rabouille
- Hubrecht Institute-KNAW & University Medical Center Utrecht, Uppsalalaan 8, 3584 CT Utrecht, The Netherlands, Department of Molecular Genetics, Weizmann Institute of Science, Rehovot 76100, Israel and The Department of Cell Biology, UMC Utrecht, The Netherlands
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31
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Graindorge A, Carré C, Gebauer F. Sex-lethal promotes nuclear retention of msl2 mRNA via interactions with the STAR protein HOW. Genes Dev 2013; 27:1421-33. [PMID: 23788626 DOI: 10.1101/gad.214999.113] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Female-specific repression of male-specific-lethal-2 (msl2) mRNA in Drosophila melanogaster provides a paradigm for coordinated control of gene expression by RNA-binding complexes. Repression is orchestrated by Sex-lethal (SXL), which binds to the 5' and 3' untranslated regions (UTRs) of the mRNA and inhibits splicing in the nucleus and subsequent translation in the cytoplasm. Here we show that SXL ensures msl2 silencing by yet a third mechanism that involves inhibition of nucleocytoplasmic transport of msl2 mRNA. To identify SXL cofactors in msl2 regulation, we devised a two-step purification method termed GRAB (GST pull-down and RNA affinity binding) and identified Held-Out-Wings (HOW) as a component of the msl2 5' UTR-associated complex. HOW directly interacts with SXL and binds to two sequence elements in the msl2 5' UTR. Depletion of HOW reduces the capacity of SXL to repress the expression of msl2 reporters without affecting SXL-mediated regulation of splicing or translation. Instead, HOW is required for SXL to retain msl2 transcripts in the nucleus. Cooperation with SXL confers a sex-specific role to HOW. Our results uncover a novel function of SXL in nuclear mRNA retention and identify HOW as a mediator of this function.
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Affiliation(s)
- Antoine Graindorge
- Gene Regulation, Stem Cells, and Cancer Programme, Centre for Genomic Regulation (CRG), 08003 Barcelona, Spain
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32
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Affiliation(s)
- Dirk Eick
- Department of Molecular Epigenetics, Helmholtz Center Munich and Center for Integrated Protein Science Munich (CIPSM), Marchioninistrasse 25, 81377 Munich,
Germany
| | - Matthias Geyer
- Center of Advanced European Studies and Research, Group Physical Biochemistry,
Ludwig-Erhard-Allee 2, 53175 Bonn, Germany
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33
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Hall MP, Nagel RJ, Fagg WS, Shiue L, Cline MS, Perriman RJ, Donohue JP, Ares M. Quaking and PTB control overlapping splicing regulatory networks during muscle cell differentiation. RNA (NEW YORK, N.Y.) 2013; 19:627-38. [PMID: 23525800 PMCID: PMC3677278 DOI: 10.1261/rna.038422.113] [Citation(s) in RCA: 120] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/17/2013] [Accepted: 02/20/2013] [Indexed: 05/26/2023]
Abstract
Alternative splicing contributes to muscle development, but a complete set of muscle-splicing factors and their combinatorial interactions are unknown. Previous work identified ACUAA ("STAR" motif) as an enriched intron sequence near muscle-specific alternative exons such as Capzb exon 9. Mass spectrometry of myoblast proteins selected by the Capzb exon 9 intron via RNA affinity chromatography identifies Quaking (QK), a protein known to regulate mRNA function through ACUAA motifs in 3' UTRs. We find that QK promotes inclusion of Capzb exon 9 in opposition to repression by polypyrimidine tract-binding protein (PTB). QK depletion alters inclusion of 406 cassette exons whose adjacent intron sequences are also enriched in ACUAA motifs. During differentiation of myoblasts to myotubes, QK levels increase two- to threefold, suggesting a mechanism for QK-responsive exon regulation. Combined analysis of the PTB- and QK-splicing regulatory networks during myogenesis suggests that 39% of regulated exons are under the control of one or both of these splicing factors. This work provides the first evidence that QK is a global regulator of splicing during muscle development in vertebrates and shows how overlapping splicing regulatory networks contribute to gene expression programs during differentiation.
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34
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Lenasi T, Barboric M. Mutual relationships between transcription and pre-mRNA processing in the synthesis of mRNA. WILEY INTERDISCIPLINARY REVIEWS-RNA 2012. [PMID: 23184646 DOI: 10.1002/wrna.1148] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The generation of messenger RNA (mRNA) in eukaryotes is achieved by transcription from the DNA template and pre-mRNA processing reactions of capping, splicing, and polyadenylation. Although RNA polymerase II (RNAPII) catalyzes the synthesis of pre-mRNA, it also serves as a principal coordinator of the processing reactions in the course of transcription. In this review, we focus on the interplay between transcription and cotranscriptional pre-mRNA maturation events, mediated by the recruitment of RNA processing factors to differentially phosphorylated C-terminal domain of Rbp1, the largest subunit of RNAPII. Furthermore, we highlight the bidirectional nature of the interplay by discussing the impact of RNAPII kinetics on pre-mRNA processing as well as how the processing events reach back to different phases of gene transcription.
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Affiliation(s)
- Tina Lenasi
- Institute of Biomedicine, Biochemistry and Developmental Biology, University of Helsinki, Helsinki, Finland.
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