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Djck1α Is Required for Proper Regeneration and Maintenance of the Medial Tissues in Planarians. Cells 2023; 12:cells12030473. [PMID: 36766815 PMCID: PMC9913719 DOI: 10.3390/cells12030473] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2022] [Revised: 01/15/2023] [Accepted: 01/30/2023] [Indexed: 02/04/2023] Open
Abstract
CK1α (Casein kinase 1α) is a member of the casein kinase 1(CK1) family that is involved in diverse cellular processes, but its functions remain unclear in stem cell development. Freshwater planarians are capable of whole-body regeneration, making it a classic model for the study of regeneration, tissue homeostasis, and polarity in vivo. To investigate the roles of CK1α in regeneration and homeostasis progress, we characterize a homolog of CK1α from planarian Dugesia japonica. We find that Djck1α, which shows an enriched expression pattern in the nascent tissues, is widely expressed especially in the medial regions of planarians. Knockdown of CK1α by RNAi presents a thicker body due to dorsal hyperplasia, along with defects in the medial tissues including nerve proliferation, missing epidermis, intestine disturbance, and hyper-proliferation during the progression of regeneration and homeostasis. Moreover, we find that the ck1α RNAi animals exhibit expansion of the midline marker slit. The eye deficiency induced by slit RNAi can be rescued by ck1α and slit double RNAi. These results suggest that ck1α is required for the medial tissue regeneration and maintenance in planarian Dugesia japonica by regulating the expression of slit, which helps to further investigate the regulation of planarian mediolateral axis.
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Hurst Z, Liu W, Shi Q, Herman PK. A distinct P-body-like granule is induced in response to the disruption of microtubule integrity in Saccharomyces cerevisiae. Genetics 2022; 222:6649695. [PMID: 35876801 PMCID: PMC9434292 DOI: 10.1093/genetics/iyac105] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2022] [Accepted: 07/08/2022] [Indexed: 11/12/2022] Open
Abstract
The Processing-body (P-body) is a conserved membraneless organelle that has been implicated in the storage and/or decay of mRNAs. Although P-bodies have been shown to be induced by a variety of conditions, the mechanisms controlling their assembly and their precise physiological roles in eukaryotic cells are still being worked out. In this study, we find that a distinct subtype of P-body is induced in response to conditions that disrupt microtubule integrity in the budding yeast, Saccharomyces cerevisiae. For example, treatment with the microtubule-destabilizing agent, benomyl, led to the induction of these novel ribonucleoprotein (RNP) granules. A link to microtubules had been noted previously and the observations here extend our understanding by demonstrating that the induced foci differ from traditional P-bodies in a number of significant ways. These include differences in overall granule morphology, protein composition and the manner in which their induction is regulated. Of particular note, several key P-body constituents are absent from these Benomyl-Induced Granules (BIGs), including the Pat1 protein that is normally required for efficient P-body assembly. However, these novel RNP structures still contain many known P-body proteins and exhibit similar hallmarks of a liquid-like compartment. In all, the data suggest that the disruption of microtubule integrity leads to the formation of a novel type of P-body granule that may have distinct biological activities in the cell. Future work will aim to identify the biological activities of these BIGs and to determine, in turn, whether these P-body-like granules have any role in the regulation of microtubule dynamics.
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Affiliation(s)
- Zachary Hurst
- Department of Molecular Genetics, Ohio State University, Columbus, Ohio 43210 USA
| | - Wenfang Liu
- Department of Molecular Genetics, Ohio State University, Columbus, Ohio 43210 USA
| | - Qian Shi
- Department of Molecular Genetics, Ohio State University, Columbus, Ohio 43210 USA
| | - Paul K Herman
- Department of Molecular Genetics, Ohio State University, Columbus, Ohio 43210 USA
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3
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Li Y, Li Y, Chen Y, Wang M, Yang J, Zhang X, Zhu L, Kong J, Min L. Genome-wide identification, evolutionary estimation and functional characterization of two cotton CKI gene types. BMC PLANT BIOLOGY 2021; 21:229. [PMID: 34022812 PMCID: PMC8140429 DOI: 10.1186/s12870-021-02990-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/13/2021] [Accepted: 04/21/2021] [Indexed: 05/03/2023]
Abstract
BACKGROUND Casein kinase I (CKI) is a kind of serine/threonine protein kinase highly conserved in plants and animals. Although molecular function of individual member of CKI family has been investigated in Arabidopsis, little is known about their evolution and functions in Gossypium. RESULTS In this study, five cotton species were applied to study CKI gene family in cotton, twenty-two species were applied to trace the origin and divergence of CKI genes. Four important insights were gained: (i) the cotton CKI genes were classified into two types based on their structural characteristics; (ii) two types of CKI genes expanded with tetraploid event in cotton; (iii) two types of CKI genes likely diverged about 1.5 billion years ago when red and green algae diverged; (iv) two types of cotton CKI genes which highly expressed in leaves showed stronger response to photoperiod (circadian clock) and light signal, and most two types of CKI genes highly expressed in anther showed identical heat inducible expression during anther development in tetraploid cotton (Gossypium hirsutum). CONCLUSION This study provides genome-wide insights into the evolutionary history of cotton CKI genes and lays a foundation for further investigation of the functional differentiation of two types of CKI genes in specific developmental processes and environmental stress conditions.
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Affiliation(s)
- Yanlong Li
- National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan , 430070, Hubei, China
| | - Yaoyao Li
- National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan , 430070, Hubei, China
- College of Life Sciences, State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, South China Agricultural University, Guangzhou , 510642, Guangdong, China
| | - Yuanyuan Chen
- National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan , 430070, Hubei, China
| | - Maojun Wang
- National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan , 430070, Hubei, China
| | - Jing Yang
- Institute of Economic Crops, Xinjiang Academy of Agricultural Sciences, Xinjiang, 830091, China
| | - Xianlong Zhang
- National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan , 430070, Hubei, China
| | - Longfu Zhu
- National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan , 430070, Hubei, China
| | - Jie Kong
- Institute of Economic Crops, Xinjiang Academy of Agricultural Sciences, Xinjiang, 830091, China.
| | - Ling Min
- National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan , 430070, Hubei, China.
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Fulcher LJ, Sapkota GP. Functions and regulation of the serine/threonine protein kinase CK1 family: moving beyond promiscuity. Biochem J 2020; 477:4603-4621. [PMID: 33306089 PMCID: PMC7733671 DOI: 10.1042/bcj20200506] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2020] [Revised: 11/09/2020] [Accepted: 11/10/2020] [Indexed: 12/11/2022]
Abstract
Regarded as constitutively active enzymes, known to participate in many, diverse biological processes, the intracellular regulation bestowed on the CK1 family of serine/threonine protein kinases is critically important, yet poorly understood. Here, we provide an overview of the known CK1-dependent cellular functions and review the emerging roles of CK1-regulating proteins in these processes. We go on to discuss the advances, limitations and pitfalls that CK1 researchers encounter when attempting to define relationships between CK1 isoforms and their substrates, and the challenges associated with ascertaining the correct physiological CK1 isoform for the substrate of interest. With increasing interest in CK1 isoforms as therapeutic targets, methods of selectively inhibiting CK1 isoform-specific processes is warranted, yet challenging to achieve given their participation in such a vast plethora of signalling pathways. Here, we discuss how one might shut down CK1-specific processes, without impacting other aspects of CK1 biology.
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Affiliation(s)
- Luke J. Fulcher
- Department of Biochemistry, University of Oxford, Oxford, U.K
| | - Gopal P. Sapkota
- Medical Research Council Protein Phosphorylation and Ubiquitylation Unit, College of Life Sciences, University of Dundee, Dundee, U.K
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Murakami-Sekimata A, Sekimata M, Sato N, Hayasaka Y, Nakano A. Deletion of PIN4 Suppresses the Protein Transport Defects Caused by sec12-4 Mutation in Saccharomyces cerevisiae. Microb Physiol 2020; 30:25-35. [PMID: 32958726 DOI: 10.1159/000509633] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2020] [Accepted: 06/24/2020] [Indexed: 11/19/2022]
Abstract
Newly synthesized secretory proteins are released into the lumen of the endoplasmic reticulum (ER). The secretory proteins are surrounded by coat protein complex II (COPII) vesicles, and transported from the ER and reach their destinations through the Golgi apparatus. Sec12p is a guanine nucleotide exchange factor for Sar1p, which initiates COPII vesicle budding from the ER. The activation of Sar1p by Sec12p and the subsequent COPII coat assembly have been well characterized, but the events that take place upstream of Sec12p remain unclear. In this study, we isolated the novel extragenic suppressor of sec12-4, PIN4/MDT1, a cell cycle checkpoint target. A yeast two-hybrid screening was used to identify Pin4/Mdt1p as a binding partner of the casein kinase I isoform Hrr25p, which we have previously identified as a modulator of Sec12p function. Deletion of PIN4 suppressed both defects of temperature-sensitive growth and the partial protein transport observed in sec12-4 mutants. The results of this study suggest that Pin4p provides novel aspects of Sec12p modulations.
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Affiliation(s)
- Akiko Murakami-Sekimata
- Division of Theoretical Nursing and Genetics, Graduate School of Medical Science, Yamagata University Faculty of Medicine, Yamagata, Japan,
| | - Masayuki Sekimata
- Radioisotope Research Center, School of Medicine, Fukushima Medical University, Fukushima, Japan
| | - Natsumi Sato
- Division of Theoretical Nursing and Genetics, Graduate School of Medical Science, Yamagata University Faculty of Medicine, Yamagata, Japan
| | - Yuto Hayasaka
- Division of Theoretical Nursing and Genetics, Graduate School of Medical Science, Yamagata University Faculty of Medicine, Yamagata, Japan
| | - Akihiko Nakano
- Live Cell Super-Resolution Imaging Research Team, Extreme Photonics Research Group, RIKEN Center for Advanced Photonics, Wako, Japan
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Shi HB, Chen N, Zhu XM, Su ZZ, Wang JY, Lu JP, Liu XH, Lin FC. The casein kinase MoYck1 regulates development, autophagy, and virulence in the rice blast fungus. Virulence 2020; 10:719-733. [PMID: 31392921 PMCID: PMC8647852 DOI: 10.1080/21505594.2019.1649588] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Casein kinases are serine/threonine protein kinases that are evolutionarily conserved in yeast and humans and are involved in a range of important cellular processes. However, the biological functions of casein kinases in the fungus Magnaporthe oryzae, the causal agent of destructive rice blast disease, are not characterized. Here, two casein kinases, MoYCK1 and MoHRR25, were identified and targeted for replacement, but only MoYCK1 was further characterized due to the possible nonviability of the MoHRR25 deletion mutant. Disruption of MoYCK1 caused pleiotropic defects in growth, conidiation, conidial germination, and appressorium formation and penetration, therefore resulting in reduced virulence in rice seedlings and barley leaves. Notably, the MoYCK1 deletion triggered quick lipidation of MoAtg8 and degradation of the autophagic marker protein GFP-MoAtg8 under nitrogen starvation conditions, in contrast to the wild type, indicating that autophagy activity was negatively regulated by MoYck1. Furthermore, we found that HOPS (homotypic fusion and vacuolar protein sorting) subunit MoVps41, a putative substrate of MoYck1, was co-located with MoAtg8 and positively required for the degradation of MoAtg8-PE and GFP-MoAtg8. In addition, MoYCK1 is also involved in the response to ionic hyperosmotic and heavy metal cation stresses. Taken together, our results revealed crucial roles of the casein kinase MoYck1 in regulating development, autophagy and virulence in M. oryzae.
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Affiliation(s)
- Huan-Bin Shi
- a State Key Laboratory of Rice Biology, Biotechnology Institute, Zhejiang University , Hangzhou , China.,b State Key Laboratory of Rice Biology, China National Rice Research Institute , Hangzhou , China
| | - Nan Chen
- a State Key Laboratory of Rice Biology, Biotechnology Institute, Zhejiang University , Hangzhou , China
| | - Xue-Ming Zhu
- a State Key Laboratory of Rice Biology, Biotechnology Institute, Zhejiang University , Hangzhou , China
| | - Zhen-Zhu Su
- a State Key Laboratory of Rice Biology, Biotechnology Institute, Zhejiang University , Hangzhou , China
| | - Jiao-Yu Wang
- c State Key Laboratory for Quality and Safety of Agro-products, Institute of Plant Protection Microbiology, Zhejiang Academy of Agricultural Science , Hangzhou , China
| | - Jian-Ping Lu
- d College of Life Sciences, Zhejiang University , Hangzhou , China
| | - Xiao-Hong Liu
- a State Key Laboratory of Rice Biology, Biotechnology Institute, Zhejiang University , Hangzhou , China
| | - Fu-Cheng Lin
- a State Key Laboratory of Rice Biology, Biotechnology Institute, Zhejiang University , Hangzhou , China
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7
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Xu P, Ianes C, Gärtner F, Liu C, Burster T, Bakulev V, Rachidi N, Knippschild U, Bischof J. Structure, regulation, and (patho-)physiological functions of the stress-induced protein kinase CK1 delta (CSNK1D). Gene 2019; 715:144005. [PMID: 31376410 DOI: 10.1016/j.gene.2019.144005] [Citation(s) in RCA: 45] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2019] [Revised: 07/19/2019] [Accepted: 07/23/2019] [Indexed: 12/11/2022]
Abstract
Members of the highly conserved pleiotropic CK1 family of serine/threonine-specific kinases are tightly regulated in the cell and play crucial regulatory roles in multiple cellular processes from protozoa to human. Since their dysregulation as well as mutations within their coding regions contribute to the development of various different pathologies, including cancer and neurodegenerative diseases, they have become interesting new drug targets within the last decade. However, to develop optimized CK1 isoform-specific therapeutics in personalized therapy concepts, a detailed knowledge of the regulation and functions of the different CK1 isoforms, their various splice variants and orthologs is mandatory. In this review we will focus on the stress-induced CK1 isoform delta (CK1δ), thereby addressing its regulation, physiological functions, the consequences of its deregulation for the development and progression of diseases, and its potential as therapeutic drug target.
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Affiliation(s)
- Pengfei Xu
- Department of General and Visceral Surgery, Surgery Center, Ulm University Hospital, Albert-Einstein-Allee 23, 89081 Ulm, Germany.
| | - Chiara Ianes
- Department of General and Visceral Surgery, Surgery Center, Ulm University Hospital, Albert-Einstein-Allee 23, 89081 Ulm, Germany.
| | - Fabian Gärtner
- Department of General and Visceral Surgery, Surgery Center, Ulm University Hospital, Albert-Einstein-Allee 23, 89081 Ulm, Germany.
| | - Congxing Liu
- Department of General and Visceral Surgery, Surgery Center, Ulm University Hospital, Albert-Einstein-Allee 23, 89081 Ulm, Germany.
| | - Timo Burster
- Department of Biology, School of Science and Technology, Nazarbayev University, 53 Kabanbay Batyr Ave, Nur-Sultan 020000, Kazakhstan.
| | - Vasiliy Bakulev
- Ural Federal University named after the first President of Russia B. N. Eltsin, Technology for Organic Synthesis Laboratory, 19 Mirastr., 620002 Ekaterinburg, Russia.
| | - Najma Rachidi
- Unité de Parasitologie Moléculaire et Signalisation, Department of Parasites and Insect Vectors, Institut Pasteur and INSERM U1201, 25-28 Rue du Dr Roux, 75015 Paris, France.
| | - Uwe Knippschild
- Department of General and Visceral Surgery, Surgery Center, Ulm University Hospital, Albert-Einstein-Allee 23, 89081 Ulm, Germany.
| | - Joachim Bischof
- Department of General and Visceral Surgery, Surgery Center, Ulm University Hospital, Albert-Einstein-Allee 23, 89081 Ulm, Germany.
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8
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It is all about the process(ing): P-body granules and the regulation of signal transduction. Curr Genet 2019; 66:73-77. [PMID: 31317215 DOI: 10.1007/s00294-019-01016-3] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2019] [Revised: 07/08/2019] [Accepted: 07/09/2019] [Indexed: 12/21/2022]
Abstract
The eukaryotic cell is subdivided into distinct functional domains by the presence of both membrane-bound and membraneless organelles. The latter include cytoplasmic granules, like the Processing-body (P-body), that are induced in response to stress and contain specific sets of mRNAs and proteins. Although P-bodies have been evolutionarily conserved, we do not yet understand the full extent of their biological functions in the cell. Early studies suggested that these structures might be sites of mRNA decay as the first protein constituents identified were enzymes involved in mRNA processing. However, more recent work indicates that this is not likely to be the primary function of these granules and has even suggested that P-bodies are sites of long-term mRNA storage. Interestingly, P-bodies and other ribonucleoprotein granules have been found to also contain a variety of signaling molecules, including protein kinases and phosphatases key to the normal control of cell growth and survival. Therefore, P-bodies could have a role in the modulation of cell signaling during particular types of stress. This review discusses both the general implications of such a proposal and one particular example that illustrates how the granule recruitment of a protein kinase can impact overall cell physiology.
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9
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Böhm T, Meng Z, Haas P, Henne-Bruns D, Rachidi N, Knippschild U, Bischof J. The kinase domain of CK1δ can be phosphorylated by Chk1. Biosci Biotechnol Biochem 2019; 83:1663-1675. [PMID: 31094292 DOI: 10.1080/09168451.2019.1617105] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Members of the casein kinase 1 (CK1) family are key regulators in numerous cellular signal transduction pathways and in order to prevent the development of certain diseases, CK1 kinase activity needs to be tightly regulated. Modulation of kinase activity by site-specific phosphorylation within the C-terminal regulatory domain of CK1δ has already been shown for several cellular kinases. By using biochemical methods, we now identified residues T161, T174, T176, and S181 within the kinase domain of CK1δ as target sites for checkpoint kinase 1 (Chk1). At least residues T176 and S181 show full conservation among CK1δ orthologues from different eukaryotic species. Enzyme kinetic analysis furthermore led to the hypothesis that site-specific phosphorylation within the kinase domain finally contributes to fine-tuning of CK1δ kinase activity. These data provide a basis for the extension of our knowledge about the role of site-specific phosphorylation for regulation of CK1δ and associated signal transduction pathways.
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Affiliation(s)
- Thomas Böhm
- a Department of General and Visceral Surgery, Surgery Centre, Ulm University Hospital , Ulm , Germany
| | - Zhigang Meng
- a Department of General and Visceral Surgery, Surgery Centre, Ulm University Hospital , Ulm , Germany
| | - Philipp Haas
- a Department of General and Visceral Surgery, Surgery Centre, Ulm University Hospital , Ulm , Germany
| | - Doris Henne-Bruns
- a Department of General and Visceral Surgery, Surgery Centre, Ulm University Hospital , Ulm , Germany
| | - Najma Rachidi
- b Unité de Parasitologie moléculaire et Signalisation, Department of Parasites and Insect Vectors, Institut Pasteur and INSERM U1201 , Paris , France
| | - Uwe Knippschild
- a Department of General and Visceral Surgery, Surgery Centre, Ulm University Hospital , Ulm , Germany
| | - Joachim Bischof
- a Department of General and Visceral Surgery, Surgery Centre, Ulm University Hospital , Ulm , Germany
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10
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Phosphorylation and Proteasome Recognition of the mRNA-Binding Protein Cth2 Facilitates Yeast Adaptation to Iron Deficiency. mBio 2018; 9:mBio.01694-18. [PMID: 30228242 PMCID: PMC6143738 DOI: 10.1128/mbio.01694-18] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Iron is a vital element for many metabolic pathways, including the synthesis of DNA and proteins, and the generation of energy via oxidative phosphorylation. Therefore, living organisms have developed tightly controlled mechanisms to properly distribute iron, since imbalances lead to nutritional deficiencies, multiple diseases, and vulnerability against pathogens. Saccharomyces cerevisiae Cth2 is a conserved mRNA-binding protein that coordinates a global reprogramming of iron metabolism in response to iron deficiency in order to optimize its utilization. Here we report that the phosphorylation of Cth2 at specific serine residues is essential to regulate the stability of the protein and adaptation to iron depletion. We identify the kinase and ubiquitination machinery implicated in this process to establish a posttranscriptional regulatory model. These results and recent findings for both mammals and plants reinforce the privileged position of E3 ubiquitin ligases and phosphorylation events in the regulation of eukaryotic iron homeostasis. Iron is an indispensable micronutrient for all eukaryotic organisms due to its participation as a redox cofactor in many metabolic pathways. Iron imbalance leads to the most frequent human nutritional deficiency in the world. Adaptation to iron limitation requires a global reorganization of the cellular metabolism directed to prioritize iron utilization for essential processes. In response to iron scarcity, the conserved Saccharomyces cerevisiae mRNA-binding protein Cth2, which belongs to the tristetraprolin family of tandem zinc finger proteins, coordinates a global remodeling of the cellular metabolism by promoting the degradation of multiple mRNAs encoding highly iron-consuming proteins. In this work, we identify a critical mechanism for the degradation of Cth2 protein during the adaptation to iron deficiency. Phosphorylation of a patch of Cth2 serine residues within its amino-terminal region facilitates recognition by the SCFGrr1 ubiquitin ligase complex, accelerating Cth2 turnover by the proteasome. When Cth2 degradation is impaired by either mutagenesis of the Cth2 serine residues or deletion of GRR1, the levels of Cth2 rise and abrogate growth in iron-depleted conditions. Finally, we uncover that the casein kinase Hrr25 phosphorylates and promotes Cth2 destabilization. These results reveal a sophisticated posttranslational regulatory pathway necessary for the adaptation to iron depletion.
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11
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P-Body Localization of the Hrr25/Casein Kinase 1 Protein Kinase Is Required for the Completion of Meiosis. Mol Cell Biol 2018; 38:MCB.00678-17. [PMID: 29915153 DOI: 10.1128/mcb.00678-17] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2017] [Accepted: 06/12/2018] [Indexed: 11/20/2022] Open
Abstract
P-bodies are liquid droplet-like compartments that lack a limiting membrane and are present in many eukaryotic cells. These structures contain specific sets of proteins and mRNAs at concentrations higher than that in the surrounding environment. Although highly conserved, the normal physiological roles of these ribonucleoprotein (RNP) granules remain poorly defined. Here, we report that P-bodies are required for the efficient completion of meiosis in the budding yeast Saccharomyces cerevisiae P-bodies were found to be present during all phases of the meiotic program and to provide protection for the Hrr25/CK1 protein kinase, a key regulator of this developmental process. A failure to associate with these RNP granules resulted in diminished levels of Hrr25 and an ensuing inability to complete meiosis. This work therefore identifies a novel function for these RNP granules and indicates how protein recruitment to these structures can have a significant impact on eukaryotic cell biology.
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12
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The Activity-Dependent Regulation of Protein Kinase Stability by the Localization to P-Bodies. Genetics 2016; 203:1191-202. [PMID: 27182950 DOI: 10.1534/genetics.116.187419] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2016] [Accepted: 05/02/2016] [Indexed: 12/21/2022] Open
Abstract
The eukaryotic cytoplasm contains a variety of ribonucleoprotein (RNP) granules in addition to the better-understood membrane-bound organelles. These granules form in response to specific stress conditions and contain a number of signaling molecules important for the control of cell growth and survival. However, relatively little is known about the mechanisms responsible for, and the ultimate consequences of, this protein localization. Here, we show that the Hrr25/CK1δ protein kinase is recruited to cytoplasmic processing bodies (P-bodies) in an evolutionarily conserved manner. This recruitment requires Hrr25 kinase activity and the Dcp2 decapping enzyme, a core constituent of these RNP granules. Interestingly, the data indicate that this localization sequesters active Hrr25 away from the remainder of the cytoplasm and thereby shields this enzyme from the degradation machinery during these periods of stress. Altogether, this work illustrates how the presence within an RNP granule can alter the ultimate fate of the localized protein.
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Karlsborn T, Tükenmez H, Mahmud AKMF, Xu F, Xu H, Byström AS. Elongator, a conserved complex required for wobble uridine modifications in eukaryotes. RNA Biol 2015; 11:1519-28. [PMID: 25607684 DOI: 10.4161/15476286.2014.992276] [Citation(s) in RCA: 81] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Elongator is a 6 subunit protein complex highly conserved in eukaryotes. The role of this complex has been controversial as the pleiotropic phenotypes of Elongator mutants have implicated the complex in several cellular processes. However, in yeast there is convincing evidence that the primary and probably only role of this complex is in formation of the 5-methoxycarbonylmethyl (mcm(5)) and 5-carbamoylmethyl (ncm(5)) side chains on uridines at wobble position in tRNA. In this review we summarize the cellular processes that have been linked to the Elongator complex and discuss its role in tRNA modification and regulation of translation. We also describe additional gene products essential for formation of ncm(5) and mcm(5) side chains at U34 and their influence on Elongator activity.
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Affiliation(s)
- Tony Karlsborn
- a Department of Molecular Biology ; Umeå University; Umeå , Sweden
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14
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Protein kinases are associated with multiple, distinct cytoplasmic granules in quiescent yeast cells. Genetics 2014; 198:1495-512. [PMID: 25342717 DOI: 10.1534/genetics.114.172031] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
The cytoplasm of the eukaryotic cell is subdivided into distinct functional domains by the presence of a variety of membrane-bound organelles. The remaining aqueous space may be further partitioned by the regulated assembly of discrete ribonucleoprotein (RNP) complexes that contain particular proteins and messenger RNAs. These RNP granules are conserved structures whose importance is highlighted by studies linking them to human disorders like amyotrophic lateral sclerosis. However, relatively little is known about the diversity, composition, and physiological roles of these cytoplasmic structures. To begin to address these issues, we examined the cytoplasmic granules formed by a key set of signaling molecules, the protein kinases of the budding yeast Saccharomyces cerevisiae. Interestingly, a significant fraction of these proteins, almost 20%, was recruited to cytoplasmic foci specifically as cells entered into the G0-like quiescent state, stationary phase. Colocalization studies demonstrated that these foci corresponded to eight different granules, including four that had not been reported previously. All of these granules were found to rapidly disassemble upon the resumption of growth, and the presence of each was correlated with cell viability in the quiescent cultures. Finally, this work also identified new constituents of known RNP granules, including the well-characterized processing body and stress granule. The composition of these latter structures is therefore more varied than previously thought and could be an indicator of additional biological activities being associated with these complexes. Altogether, these observations indicate that quiescent yeast cells contain multiple distinct cytoplasmic granules that may make important contributions to their long-term survival.
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15
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Tanaka C, Tan LJ, Mochida K, Kirisako H, Koizumi M, Asai E, Sakoh-Nakatogawa M, Ohsumi Y, Nakatogawa H. Hrr25 triggers selective autophagy-related pathways by phosphorylating receptor proteins. ACTA ACUST UNITED AC 2014; 207:91-105. [PMID: 25287303 PMCID: PMC4195827 DOI: 10.1083/jcb.201402128] [Citation(s) in RCA: 96] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
The budding yeast kinase Hrr25 regulates two selective autophagy–related pathways by phosphorylating degradation target receptors and thereby promoting their interaction with Atg11 and the formation of autophagosomal membrane. In selective autophagy, degradation targets are specifically recognized, sequestered by the autophagosome, and transported into the lysosome or vacuole. Previous studies delineated the molecular basis by which the autophagy machinery recognizes those targets, but the regulation of this process is still poorly understood. In this paper, we find that the highly conserved multifunctional kinase Hrr25 regulates two distinct selective autophagy–related pathways in Saccharomyces cerevisiae. Hrr25 is responsible for the phosphorylation of two receptor proteins: Atg19, which recognizes the assembly of vacuolar enzymes in the cytoplasm-to-vacuole targeting pathway, and Atg36, which recognizes superfluous peroxisomes in pexophagy. Hrr25-mediated phosphorylation enhances the interactions of these receptors with the common adaptor Atg11, which recruits the core autophagy-related proteins that mediate the formation of the autophagosomal membrane. Thus, this study introduces regulation of selective autophagy as a new role of Hrr25 and, together with other recent studies, reveals that different selective autophagy–related pathways are regulated by a uniform mechanism: phosphoregulation of the receptor–adaptor interaction.
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Affiliation(s)
- Chikara Tanaka
- Frontier Research Center and Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, Midori-ku, Yokohama 226-8503, Japan
| | - Li-Jing Tan
- Frontier Research Center and Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, Midori-ku, Yokohama 226-8503, Japan
| | - Keisuke Mochida
- Frontier Research Center and Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, Midori-ku, Yokohama 226-8503, Japan
| | - Hiromi Kirisako
- Frontier Research Center and Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, Midori-ku, Yokohama 226-8503, Japan
| | - Michiko Koizumi
- Frontier Research Center and Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, Midori-ku, Yokohama 226-8503, Japan
| | - Eri Asai
- Frontier Research Center and Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, Midori-ku, Yokohama 226-8503, Japan
| | - Machiko Sakoh-Nakatogawa
- Frontier Research Center and Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, Midori-ku, Yokohama 226-8503, Japan
| | - Yoshinori Ohsumi
- Frontier Research Center and Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, Midori-ku, Yokohama 226-8503, Japan
| | - Hitoshi Nakatogawa
- Frontier Research Center and Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, Midori-ku, Yokohama 226-8503, Japan Frontier Research Center and Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, Midori-ku, Yokohama 226-8503, Japan
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16
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Mochida K, Ohsumi Y, Nakatogawa H. Hrr25 phosphorylates the autophagic receptor Atg34 to promote vacuolar transport of α-mannosidase under nitrogen starvation conditions. FEBS Lett 2014; 588:3862-9. [PMID: 25281559 DOI: 10.1016/j.febslet.2014.09.032] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2014] [Revised: 09/17/2014] [Accepted: 09/17/2014] [Indexed: 01/08/2023]
Abstract
In Saccharomyces cerevisiae, under nitrogen-starvation conditions, the α-mannosidase Ams1 is recognized by the autophagic receptor Atg34 and transported into the vacuole, where it functions as an active enzyme. In this study, we identified Hrr25 as the kinase that phosphorylates Atg34 under these conditions. Hrr25-mediated phosphorylation does not affect the interaction of Atg34 with Ams1, but instead promotes Atg34 binding to the adaptor protein Atg11, which recruits the autophagy machinery to the Ams1-Atg34 complex, resulting in activation of the vacuolar transport of Ams1. Our findings reveal the regulatory mechanism of a biosynthetic pathway mediated by the autophagy machinery.
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Affiliation(s)
- Keisuke Mochida
- Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, Japan
| | | | - Hitoshi Nakatogawa
- Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, Japan; Frontier Research Center, Tokyo Institute of Technology, Japan.
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17
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Knippschild U, Krüger M, Richter J, Xu P, García-Reyes B, Peifer C, Halekotte J, Bakulev V, Bischof J. The CK1 Family: Contribution to Cellular Stress Response and Its Role in Carcinogenesis. Front Oncol 2014; 4:96. [PMID: 24904820 PMCID: PMC4032983 DOI: 10.3389/fonc.2014.00096] [Citation(s) in RCA: 188] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2014] [Accepted: 04/18/2014] [Indexed: 12/19/2022] Open
Abstract
Members of the highly conserved and ubiquitously expressed pleiotropic CK1 family play major regulatory roles in many cellular processes including DNA-processing and repair, proliferation, cytoskeleton dynamics, vesicular trafficking, apoptosis, and cell differentiation. As a consequence of cellular stress conditions, interaction of CK1 with the mitotic spindle is manifold increased pointing to regulatory functions at the mitotic checkpoint. Furthermore, CK1 is able to alter the activity of key proteins in signal transduction and signal integration molecules. In line with this notion, CK1 is tightly connected to the regulation and degradation of β-catenin, p53, and MDM2. Considering the importance of CK1 for accurate cell division and regulation of tumor suppressor functions, it is not surprising that mutations and alterations in the expression and/or activity of CK1 isoforms are often detected in various tumor entities including cancer of the kidney, choriocarcinomas, breast carcinomas, oral cancer, adenocarcinomas of the pancreas, and ovarian cancer. Therefore, scientific effort has enormously increased (i) to understand the regulation of CK1 and its involvement in tumorigenesis- and tumor progression-related signal transduction pathways and (ii) to develop CK1-specific inhibitors for the use in personalized therapy concepts. In this review, we summarize the current knowledge regarding CK1 regulation, function, and interaction with cellular proteins playing central roles in cellular stress-responses and carcinogenesis.
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Affiliation(s)
- Uwe Knippschild
- Department of General and Visceral Surgery, Surgery Center, Ulm University Hospital , Ulm , Germany
| | - Marc Krüger
- Department of General and Visceral Surgery, Surgery Center, Ulm University Hospital , Ulm , Germany
| | - Julia Richter
- Department of General and Visceral Surgery, Surgery Center, Ulm University Hospital , Ulm , Germany
| | - Pengfei Xu
- Department of General and Visceral Surgery, Surgery Center, Ulm University Hospital , Ulm , Germany
| | - Balbina García-Reyes
- Department of General and Visceral Surgery, Surgery Center, Ulm University Hospital , Ulm , Germany
| | - Christian Peifer
- Institute for Pharmaceutical Chemistry, Christian Albrechts University , Kiel , Germany
| | - Jakob Halekotte
- Institute for Pharmaceutical Chemistry, Christian Albrechts University , Kiel , Germany
| | - Vasiliy Bakulev
- Department of Organic Synthesis, Ural Federal University , Ekaterinburg , Russia
| | - Joachim Bischof
- Department of General and Visceral Surgery, Surgery Center, Ulm University Hospital , Ulm , Germany
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18
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Greer YE, Westlake CJ, Gao B, Bharti K, Shiba Y, Xavier CP, Pazour GJ, Yang Y, Rubin JS. Casein kinase 1δ functions at the centrosome and Golgi to promote ciliogenesis. Mol Biol Cell 2014; 25:1629-40. [PMID: 24648492 PMCID: PMC4019494 DOI: 10.1091/mbc.e13-10-0598] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
CK1δ acts at the centrosome and Golgi to support polarized transport for ciliogenesis. It controls distribution of ciliary effectors Rab11, Rab8, CEP290, PCM1, and IFT20 and also promotes MT nucleation at the Golgi and positioning and integrity of the Golgi. Interaction of CK1δ with AKAP450 mediates Golgi MT nucleation and ciliogenesis. Inhibition of casein kinase 1 delta (CK1δ) blocks primary ciliogenesis in human telomerase reverse transcriptase immortalized retinal pigmented epithelial and mouse inner medullary collecting duct cells-3. Mouse embryonic fibroblasts (MEFs) and retinal cells from Csnk1d (CK1δ)-null mice also exhibit ciliogenesis defects. CK1δ catalytic activity and centrosomal localization signal (CLS) are required to rescue cilia formation in MEFsCsnk1d null. Furthermore, expression of a truncated derivative containing the CLS displaces full-length CK1δ from the centrosome and decreases ciliary length in control MEFs, suggesting that centrosomal CK1δ has a role in ciliogenesis. CK1δ inhibition also alters pericentrosomal or ciliary distribution of several proteins involved in ciliary transport, including Ras-like in rat brain-11A, Ras-like in rat brain-8A, centrosomal protein of 290 kDa, pericentriolar material protein 1, and polycystin-2, as well as the Golgi distribution of its binding partner, A-kinase anchor protein 450 (AKAP450). As reported for AKAP450, CK1δ was required for microtubule nucleation at the Golgi and maintenance of Golgi integrity. Overexpression of an AKAP450 fragment containing the CK1δ-binding site inhibits Golgi-derived microtubule nucleation, Golgi distribution of intraflagellar transport protein 20 homologue, and ciliogenesis. Our results suggest that CK1δ mediates primary ciliogenesis by multiple mechanisms, one involving its centrosomal function and another dependent on its interaction with AKAP450 at the Golgi, where it is important for maintaining Golgi organization and polarized trafficking of multiple factors that mediate ciliary transport.
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Affiliation(s)
- Yoshimi Endo Greer
- Laboratory of Cellular and Molecular Biology, National Cancer Institute, Bethesda, MD 20892
| | - Christopher J Westlake
- Laboratory of Cell and Developmental Signaling, National Cancer Institute, Frederick, MD 21702
| | - Bo Gao
- Genetic Disease Research Branch, National Human Genome Research Institute, Bethesda, MD 20892
| | - Kapil Bharti
- Ophthalmic Genetics and Visual Function Branch, National Eye Institute, Bethesda, MD 20892
| | - Yoko Shiba
- Laboratory of Cellular and Molecular Biology, National Cancer Institute, Bethesda, MD 20892
| | - Charles P Xavier
- Laboratory of Cellular and Molecular Biology, National Cancer Institute, Bethesda, MD 20892
| | - Gregory J Pazour
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA 01605
| | - Yingzi Yang
- Genetic Disease Research Branch, National Human Genome Research Institute, Bethesda, MD 20892
| | - Jeffrey S Rubin
- Laboratory of Cellular and Molecular Biology, National Cancer Institute, Bethesda, MD 20892
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19
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Gorietti D, Zanni E, Palleschi C, Delfini M, Uccelletti D, Saliola M, Miccheli A. Depletion of casein kinase I leads to a NAD(P)(+)/NAD(P)H balance-dependent metabolic adaptation as determined by NMR spectroscopy-metabolomic profile in Kluyveromyces lactis. Biochim Biophys Acta Gen Subj 2013; 1840:556-64. [PMID: 24144565 DOI: 10.1016/j.bbagen.2013.10.020] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2013] [Revised: 09/25/2013] [Accepted: 10/12/2013] [Indexed: 01/01/2023]
Abstract
BACKGROUND In the Crabtree-negative Kluyveromyces lactis yeast the rag8 mutant is one of nineteen complementation groups constituting the fermentative-deficient model equivalent to the Saccharomyces cerevisiae respiratory petite mutants. These mutants display pleiotropic defects in membrane fatty acids and/or cell walls, osmo-sensitivity and the inability to grow under strictly anaerobic conditions (Rag(-) phenotype). RAG8 is an essential gene coding for the casein kinase I, an evolutionary conserved activity involved in a wide range of cellular processes coordinating morphogenesis and glycolytic flux with glucose/oxygen sensing. METHODS A metabolomic approach was performed by NMR spectroscopy to investigate how the broad physiological roles of Rag8, taken as a model for all rag mutants, coordinate cellular responses. RESULTS Statistical analysis of metabolomic data showed a significant increase in the level of metabolites in reactions directly involved in the reoxidation of the NAD(P)H in rag8 mutant samples with respect to the wild type ones. We also observed an increased de novo synthesis of nicotinamide adenine dinucleotide. On the contrary, the production of metabolites in pathways leading to the reduction of the cofactors was reduced. CONCLUSIONS The changes in metabolite levels in rag8 showed a metabolic adaptation that is determined by the intracellular NAD(P)(+)/NAD(P)H redox balance state. GENERAL SIGNIFICANCE The inadequate glycolytic flux of the mutant leads to a reduced/asymmetric distribution of acetyl-CoA to the different cellular compartments with loss of the fatty acid dynamic respiratory/fermentative adaptive balance response.
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Affiliation(s)
- D Gorietti
- Department of Chemistry, Sapienza University of Rome, Piazzale A. Moro 5, 00185 Rome, Italy.
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20
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Skelding KA, Rostas JAP. The role of molecular regulation and targeting in regulating calcium/calmodulin stimulated protein kinases. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2012; 740:703-30. [PMID: 22453966 DOI: 10.1007/978-94-007-2888-2_31] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Calcium/calmodulin-stimulated protein kinases can be classified as one of two types - restricted or multifunctional. This family of kinases contains several structural similarities: all possess a calmodulin binding motif and an autoinhibitory region. In addition, all of the calcium/calmodulin-stimulated protein kinases examined in this chapter are regulated by phosphorylation, which either activates or inhibits their kinase activity. However, as the multifunctional calcium/calmodulin-stimulated protein kinases are ubiquitously expressed, yet regulate a broad range of cellular functions, additional levels of regulation that control these cell-specific functions must exist. These additional layers of control include gene expression, signaling pathways, and expression of binding proteins and molecular targeting. All of the multifunctional calcium/calmodulin-stimulated protein kinases examined in this chapter appear to be regulated by these additional layers of control, however, this does not appear to be the case for the restricted kinases.
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Affiliation(s)
- Kathryn A Skelding
- School of Biomedical Sciences and Pharmacy and Hunter Medical Research Institute, Faculty of Health, The University of Newcastle, University Drive, Callaghan, NSW 2308, Australia
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21
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Ikeda K, Zhapparova O, Brodsky I, Semenova I, Tirnauer JS, Zaliapin I, Rodionov V. CK1 activates minus-end-directed transport of membrane organelles along microtubules. Mol Biol Cell 2011; 22:1321-9. [PMID: 21307338 PMCID: PMC3078062 DOI: 10.1091/mbc.e10-09-0741] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
This study shows that the signal transduction pathway responsible for the initiation of minus-end–directed movement of membrane-bounded pigment granules in melanophores involves sequential activation of protein phosphatase 2A and casein kinase 1 and that this activation correlates with increased phosphorylation of the dynein intermediate chain. Microtubule (MT)-based organelle transport is driven by MT motor proteins that move cargoes toward MT minus-ends clustered in the cell center (dyneins) or plus-ends extended to the periphery (kinesins). Cells are able to rapidly switch the direction of transport in response to external cues, but the signaling events that control switching remain poorly understood. Here, we examined the signaling mechanism responsible for the rapid activation of dynein-dependent MT minus-end–directed pigment granule movement in Xenopus melanophores (pigment aggregation). We found that, along with the previously identified protein phosphatase 2A (PP2A), pigment aggregation signaling also involved casein kinase 1ε (CK1ε), that both enzymes were bound to pigment granules, and that their activities were increased during pigment aggregation. Furthermore we found that CK1ε functioned downstream of PP2A in the pigment aggregation signaling pathway. Finally, we discovered that stimulation of pigment aggregation increased phosphorylation of dynein intermediate chain (DIC) and that this increase was partially suppressed by CK1ε inhibition. We propose that signal transduction during pigment aggregation involves successive activation of PP2A and CK1ε and CK1ε-dependent phosphorylation of DIC, which stimulates dynein motor activity and increases minus-end–directed runs of pigment granules.
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Affiliation(s)
- Kazuho Ikeda
- Department of Cell Biology, University of Connecticut Health Center, Farmington, CT 06030, USA
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22
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Kim MJ, Go YS, Lee SB, Kim YS, Shin JS, Min MK, Hwang I, Suh MC. Seed-expressed casein kinase I acts as a positive regulator of the SeFAD2 promoter via phosphorylation of the SebHLH transcription factor. PLANT MOLECULAR BIOLOGY 2010; 73:425-37. [PMID: 20349267 DOI: 10.1007/s11103-010-9630-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/17/2009] [Accepted: 03/11/2010] [Indexed: 05/09/2023]
Abstract
Microsomal oleic acid desaturase (FAD2) catalyzes the first committed step of the biosynthesis of polyunsaturated fatty acids via extra-plastidial desaturation of oleic acid to linoleic acid. In the regulatory mechanism controlling seed-specific SeFAD2 expression, trans-activation of the seed-specific SeFAD2 promoter is mediated by the SebHLH transcription factor (Kim et al. in Plant Mol Biol 64:453-466, 2007). In this study, a protein interacting with SebHLH was isolated from yeast two-hybrid analysis. The protein shares approximately 80% sequence identity with other putative casein kinases and was named SeCKI (Sesame Casein Kinase I). SeCKI transcripts were predominantly expressed in developing sesame seeds and were induced approximately threefold by exogenous application of ABA. eGFP:SeCKI fusion protein was localized to the nucleus. The SeCKI protein specifically bound to SebHLH. The SeCKI protein was autophosphorylated in a calcium-independent manner and transphosphorylated the SebHLH protein. Both the SebHLH and the SeCKI genes or both the SebHLH and mutated SemCKI (K182G) genes, under the control of CaMV 35S promoter, and the GUS reporter gene driven by SeFAD2 promoter containing E- and G-Box motifs were co-expressed in developing sesame seeds. This co-expression revealed that SeCKI enhanced the SebHLH-mediated transactivation of the SeFAD2 gene promoter via phosphorylation of the SebHLH transcription factor.
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Affiliation(s)
- Mi Jung Kim
- School of Life Sciences and Biotechnology, Korea University, Seoul 136-701, Korea
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23
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Kim MJ, Go YS, Lee SB, Kim YS, Shin JS, Min MK, Hwang I, Suh MC. Seed-expressed casein kinase I acts as a positive regulator of the SeFAD2 promoter via phosphorylation of the SebHLH transcription factor. PLANT MOLECULAR BIOLOGY 2010; 73:425-437. [PMID: 20349267 DOI: 10.1007/s11103-010-9630-9637] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Received: 08/17/2009] [Accepted: 03/11/2010] [Indexed: 05/24/2023]
Abstract
Microsomal oleic acid desaturase (FAD2) catalyzes the first committed step of the biosynthesis of polyunsaturated fatty acids via extra-plastidial desaturation of oleic acid to linoleic acid. In the regulatory mechanism controlling seed-specific SeFAD2 expression, trans-activation of the seed-specific SeFAD2 promoter is mediated by the SebHLH transcription factor (Kim et al. in Plant Mol Biol 64:453-466, 2007). In this study, a protein interacting with SebHLH was isolated from yeast two-hybrid analysis. The protein shares approximately 80% sequence identity with other putative casein kinases and was named SeCKI (Sesame Casein Kinase I). SeCKI transcripts were predominantly expressed in developing sesame seeds and were induced approximately threefold by exogenous application of ABA. eGFP:SeCKI fusion protein was localized to the nucleus. The SeCKI protein specifically bound to SebHLH. The SeCKI protein was autophosphorylated in a calcium-independent manner and transphosphorylated the SebHLH protein. Both the SebHLH and the SeCKI genes or both the SebHLH and mutated SemCKI (K182G) genes, under the control of CaMV 35S promoter, and the GUS reporter gene driven by SeFAD2 promoter containing E- and G-Box motifs were co-expressed in developing sesame seeds. This co-expression revealed that SeCKI enhanced the SebHLH-mediated transactivation of the SeFAD2 gene promoter via phosphorylation of the SebHLH transcription factor.
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Affiliation(s)
- Mi Jung Kim
- School of Life Sciences and Biotechnology, Korea University, Seoul 136-701, Korea
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24
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Ben-Nissan G, Cui W, Kim DJ, Yang Y, Yoo BC, Lee JY. Arabidopsis casein kinase 1-like 6 contains a microtubule-binding domain and affects the organization of cortical microtubules,. PLANT PHYSIOLOGY 2008; 4:652-4. [PMID: 18945931 PMCID: PMC2593671 DOI: 10.1104/pp.108.129346] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/05/2008] [Accepted: 10/17/2008] [Indexed: 05/18/2023]
Abstract
Members of the casein kinase 1 (CK1) family are evolutionarily conserved eukaryotic protein kinases that are involved in various cellular, physiological, and developmental processes in yeast and metazoans, but the biological roles of CK1 members in plants are not well understood. Here, we report that an Arabidopsis (Arabidopsis thaliana) CK1 member named casein kinase 1-like 6 (CKL6) associates with cortical microtubules in vivo and phosphorylates tubulins in vitro. The unique C-terminal domain of CKL6 was shown to contain the signal that allows localization of CKL6 to the cortical microtubules. This domain on its own was sufficient to associate with microtubules in vivo and to bind tubulins in vitro. CKL6 was able to phosphorylate soluble tubulins as well as microtubule polymers, and its endogenous activity was found to associate with a tubulin-enriched subcellular fraction. Two major in vitro phosphorylation sites were mapped to serine-413 and serine-420 of tubulin beta. Ectopic expression of wild-type CKL6 or a kinase-inactive mutant form induced alterations in cortical microtubule organization and anisotropic cell expansion. Collectively, these results demonstrate that CKL6 is a protein kinase containing a novel tubulin-binding domain and plays a role in anisotropic cell growth and shape formation in Arabidopsis through the regulation of microtubule organization, possibly through the phosphorylation of tubulins.
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Affiliation(s)
- Gili Ben-Nissan
- Department of Plant and Soil Sciences, Delaware Biotechnology Institute, University of Delaware, Newark, Delaware 19711, USA
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25
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Grozav AG, Chikamori K, Kozuki T, Grabowski DR, Bukowski RM, Willard B, Kinter M, Andersen AH, Ganapathi R, Ganapathi MK. Casein kinase I delta/epsilon phosphorylates topoisomerase IIalpha at serine-1106 and modulates DNA cleavage activity. Nucleic Acids Res 2008; 37:382-92. [PMID: 19043076 PMCID: PMC2632902 DOI: 10.1093/nar/gkn934] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
We previously reported that phosphorylation of topoisomerase (topo) IIα at serine-1106 (Ser-1106) regulates enzyme activity and sensitivity to topo II-targeted drugs. In this study we demonstrate that phosphorylation of Ser-1106, which is flanked by acidic amino acids, is regulated in vivo by casein kinase (CK) Iδ and/or CKIɛ, but not by CKII. The CKI inhibitors, CKI-7 and IC261, reduced Ser-1106 phosphorylation and decreased formation of etoposide-stabilized topo II–DNA cleavable complex. In contrast, the CKII inhibitor, 5,6-dichlorobenzimidazole riboside, did not affect etoposide-stabilized topo II–DNA cleavable complex formation. Since, IC261 specifically targets the Ca2+-regulated isozymes, CKIδ and CKIɛ, we examined the effect of down-regulating these enzymes on Ser-1106 phosphorylation. Down-regulation of these isozymes with targeted si-RNAs led to hypophosphorylation of the Ser-1106 containing peptide. However, si-RNA-mediated down-regulation of CKIIα and α′ did not alter Ser-1106 phosphorylation. Furthermore, reduced phosphorylation of Ser-1106, observed in HRR25 (CKIδ/ɛ homologous gene)-deleted Saccharomyces cerevisiae cells transformed with human topo IIα, was enhanced following expression of human CKIɛ. Down-regulation of CKIδ and CKIɛ also led to reduced formation of etoposide stabilized topo II–DNA cleavable complex. These results provide strong support for an essential role of CKIδ/ɛ in phosphorylating Ser-1106 in human topo IIα and in regulating enzyme function.
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Affiliation(s)
- Adrian G Grozav
- Clinical Pharmacology Program, Taussig Cancer Institute, Cleveland, OH 44195, USA
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26
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Huang B, Lu J, Byström AS. A genome-wide screen identifies genes required for formation of the wobble nucleoside 5-methoxycarbonylmethyl-2-thiouridine in Saccharomyces cerevisiae. RNA (NEW YORK, N.Y.) 2008; 14:2183-94. [PMID: 18755837 PMCID: PMC2553728 DOI: 10.1261/rna.1184108] [Citation(s) in RCA: 127] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
We recently showed that the gamma-subunit of Kluyveromyces lactis killer toxin (gamma-toxin) is a tRNA endonuclease that cleaves tRNA(mcm5s2UUC Glu), tRNA(mcm5s2UUU Lys), and tRNA(mcm5s2UUG Gln) 3' of the wobble nucleoside 5-methoxycarbonylmethyl-2-thiouridine (mcm(5)s(2)U). The 5-methoxycarbonylmethyl (mcm(5)) side chain was important for efficient cleavage by gamma-toxin, and defects in mcm(5) side-chain synthesis correlated with resistance to gamma-toxin. Based on this correlation, a genome-wide screen was performed to identify gene products involved in the formation of the mcm(5) side chain. From a collection of 4826 homozygous diploid Saccharomyces cerevisiae strains, each with one nonessential gene deleted, 63 mutants resistant to Kluyveromyces lactis killer toxin were identified. Among these, eight were earlier identified to have a defect in formation of the mcm(5) side chain. Analysis of the remaining mutants and other known gamma-toxin resistant mutants revealed that sit4, kti14, and KTI5 mutants also have a defect in the formation of mcm(5). A mutant lacking two of the Sit4-associated proteins, Sap185 and Sap190, displays the same modification defect as a sit4-null mutant. Interestingly, several mutants were found to be defective in the synthesis of the 2-thio (s(2)) group of the mcm(5)s(2)U nucleoside. In addition to earlier described mutants, formation of the s(2) group was also abolished in urm1, uba4, and ncs2 mutants and decreased in the yor251c mutant. Like the absence of the mcm(5) side chain, the lack of the s(2) group renders tRNA(mcm5s2UUC Glu) less sensitive to gamma-toxin, reinforcing the importance of the wobble nucleoside mcm(5)s(2)U for tRNA cleavage by gamma-toxin.
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Affiliation(s)
- Bo Huang
- Department of Molecular Biology, Umeå University, 901 87 Umeå, Sweden
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27
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Ray P, Basu U, Ray A, Majumdar R, Deng H, Maitra U. The Saccharomyces cerevisiae 60 S ribosome biogenesis factor Tif6p is regulated by Hrr25p-mediated phosphorylation. J Biol Chem 2008; 283:9681-91. [PMID: 18256024 DOI: 10.1074/jbc.m710294200] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The biosynthesis of 60 S ribosomal subunits in Saccharomyces cerevisiae requires Tif6p, the yeast homologue of mammalian eIF6. This protein is necessary for the formation of 60 S ribosomal subunits because it is essential for the processing of 35 S pre-rRNA to the mature 25 S and 5.8 S rRNAs. In the present work, using molecular genetic and biochemical analyses, we show that Hrr25p, an isoform of yeast casein kinase I, phosphorylates Tif6p both in vitro and in vivo. Tryptic phosphopeptide mapping of in vitro phosphorylated Tif6p by Hrr25p and (32)P-labeled Tif6p isolated from yeast cells followed by mass spectrometric analysis revealed that phosphorylation occurred on a single tryptic peptide at Ser-174. Sucrose gradient fractionation and coimmunoprecipitation experiments demonstrate that a small but significant fraction of Hrr25p is bound to 66 S preribosomal particles that also contain bound Tif6p. Depletion of Hrr25p from a conditional yeast mutant that fails to phosphorylate Tif6p was unable to process pre-rRNAs efficiently, resulting in significant reduction in the formation of 25 S rRNA. These results along with our previous observations that phosphorylatable Ser-174 is required for yeast cell growth and viability, suggest that Hrr25p-mediated phosphorylation of Tif6p plays a critical role in the biogenesis of 60 S ribosomal subunits in yeast cells.
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Affiliation(s)
- Partha Ray
- Department of Developmental and Molecular Biology, Albert Einstein College of Medicine of Yeshiva University, Bronx, NY 10461, USA
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28
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Guan J, Li H, Rogulja A, Axelrod JD, Cadigan KM. The Drosophila casein kinase Iepsilon/delta Discs overgrown promotes cell survival via activation of DIAP1 expression. Dev Biol 2006; 303:16-28. [PMID: 17134692 PMCID: PMC2892850 DOI: 10.1016/j.ydbio.2006.10.028] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2006] [Revised: 10/17/2006] [Accepted: 10/18/2006] [Indexed: 01/07/2023]
Abstract
The proper number of cells in developing tissues is achieved by coordinating cell division with apoptosis. In Drosophila, the adult wing is derived from wing imaginal discs, which undergo a period of growth and proliferation during larval stages without much programmed cell death. In this report, we demonstrate that the Drosophila casein kinase Iepsilon/delta, known as Discs overgrown (Dco), is required for maintaining this low level of apoptosis. Expression of dco can suppress the apoptotic activity of Head involution defective (Hid) in the developing eye. Loss of dco in the wing disc results in a dramatic reduction in expression of the caspase inhibitor DIAP1 and a concomitant activation of caspases. The regulation of DIAP1 by Dco occurs by a post-transcriptional mechanism that is independent of hid. Mutant clones of dco are considerably smaller than controls even when apoptosis is inhibited, suggesting that Dco promotes cell division/growth in addition to its role in cell survival. The dco phenotype cannot be explained by defects Wingless (Wg) signaling. We propose that Dco coordinates tissue size by stimulating cell division/growth and blocking apoptosis via activation of DIAP1 expression.
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Affiliation(s)
- Ju Guan
- Department of Molecular, Cellular and Developmental Biology, University of Michigan, Natural Science Building, Ann Arbor MI 48109-1048, USA
| | - Hui Li
- Department of Molecular, Cellular and Developmental Biology, University of Michigan, Natural Science Building, Ann Arbor MI 48109-1048, USA
| | - Ana Rogulja
- Department of Molecular, Cellular and Developmental Biology, University of Michigan, Natural Science Building, Ann Arbor MI 48109-1048, USA
| | - Jeff D. Axelrod
- Department of Pathology, Stanford University School of Medicine, Stanford CA 94305
| | - Ken M. Cadigan
- Department of Molecular, Cellular and Developmental Biology, University of Michigan, Natural Science Building, Ann Arbor MI 48109-1048, USA
- Corresponding author. Fax: +1 734 647-0884. Email address: (K. Cadigan)
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29
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Abstract
MDMX is a homolog of MDM2 that is critical for regulating p53 function during mouse development. MDMX degradation is regulated by MDM2-mediated ubiquitination. Whether there are other mechanisms of MDMX regulation is largely unknown. We found that MDMX binds to the casein kinase 1 alpha isoform (CK1alpha) and is phosphorylated by CK1alpha. Expression of CK1alpha stimulates the ability of MDMX to bind to p53 and inhibit p53 transcriptional function. Regulation of MDMX-p53 interaction requires CK1alpha binding to the central region of MDMX and phosphorylation of MDMX on serine 289. Inhibition of CK1alpha expression by isoform-specific small interfering RNA (siRNA) activates p53 and further enhances p53 activity after ionizing irradiation. CK1alpha siRNA also cooperates with DNA damage to induce apoptosis. These results suggest that CK1alpha is a functionally relevant MDMX-binding protein and plays an important role in regulating p53 activity in the absence or presence of stress.
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Affiliation(s)
- Lihong Chen
- H. Lee Moffitt Cancer Center, MRC3057A, 12902 Magnolia Drive, Tampa, FL 33612, USA
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30
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Horiguchi R, Yoshikuni M, Tokumoto M, Nagahama Y, Tokumoto T. Identification of a protein kinase which phosphorylates a subunit of the 26S proteasome and changes in its activity during meiotic cell cycle in goldfish oocytes. Cell Signal 2005; 17:205-15. [PMID: 15494212 DOI: 10.1016/j.cellsig.2004.07.002] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2004] [Accepted: 07/06/2004] [Indexed: 11/23/2022]
Abstract
The proteasome is involved in the progression of the meiotic cell cycle in fish oocytes. We reported that the alpha4 subunit of the 26S proteasome, which is a component of the outer rings of the 20S proteasome, is phosphorylated in immature oocytes and dephosphorylated in mature oocytes. To investigate the role of the phosphorylation, we purified the protein kinase from immature oocytes using a recombinant alpha4 subunit as substrate. A protein band which well corresponded to the kinase activity was identified as casein kinase Ialpha (CKIalpha). Two-dimensional (2D) PAGE analysis showed that part of the alpha4 subunit was phosphorylated by CKIalpha in vitro. This spot was detected in purified immature 26S proteasome but not in mature 26S proteasome, demonstrate that the alpha4 subunit is phosphorylated by CKIalpha meiotic cell cycle dependently.
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Affiliation(s)
- Ryo Horiguchi
- Department of Molecular Biomechanics, The Graduate University for Advanced Studies, Okazaki 444-8585, Japan
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31
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Knippschild U, Gocht A, Wolff S, Huber N, Löhler J, Stöter M. The casein kinase 1 family: participation in multiple cellular processes in eukaryotes. Cell Signal 2005; 17:675-89. [PMID: 15722192 DOI: 10.1016/j.cellsig.2004.12.011] [Citation(s) in RCA: 423] [Impact Index Per Article: 22.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2004] [Revised: 12/22/2004] [Accepted: 12/22/2004] [Indexed: 12/11/2022]
Abstract
Phosphorylation of serine, threonine and tyrosine residues by cellular protein kinases plays an important role in the regulation of various cellular processes. The serine/threonine specific casein kinase 1 and 2 protein kinase families--(CK1 and CK2)--were among the first protein kinases that had been described. In recent years our knowledge of the regulation and function of mammalian CK1 kinase family members has rapidly increased. Extracellular stimuli, the subcellular localization of CK1 isoforms, their interaction with various cellular structures and proteins, as well as autophosphorylation and proteolytic cleavage of their C-terminal regulatory domains influence CK1 kinase activity. Mammalian CK1 isoforms phosphorylate many different substrates among them key regulatory proteins involved in the control of cell differentiation, proliferation, chromosome segregation and circadian rhythms. Deregulation and/or the incidence of mutations in the coding sequence of CK1 isoforms have been linked to neurodegenerative diseases and cancer. This review will summarize our current knowledge about the function and regulation of mammalian CK1 isoforms.
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Affiliation(s)
- Uwe Knippschild
- Department of Visceral and Transplantation Surgery, University of Ulm, Steinhövelstr. 9, 89075 Ulm, Germany.
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32
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Horiguchi R, Tokumoto M, Nagahama Y, Tokumoto T. Molecular cloning and expression of cDNA coding for four spliced isoforms of casein kinase Ialpha in goldfish oocytes. ACTA ACUST UNITED AC 2004; 1727:75-80. [PMID: 15652160 DOI: 10.1016/j.bbaexp.2004.11.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2004] [Revised: 10/05/2004] [Accepted: 11/09/2004] [Indexed: 11/16/2022]
Abstract
Casein kinase I (CKI) is a member of the serine/threonine protein kinases and located in a separate group within the superfamily of eukaryotic protein kinases. CKI isoforms regulate several checkpoints of the cell cycle and meiosis. In higher eukaryotes, CKIalpha has four isoforms produced through the alternative splicing of two short inserts. Here, we report the cloning, sequencing and expression of four alternatively spliced isoforms of CKIalpha from goldfish ovary. The cloned cDNAs were 2099-3002-bp long and classified as CKIalpha, CKIalphaS, CKIalphaL and CKIalphaLS. It was revealed that two major (3.0 and 2.0 kb) messages were strongly expressed in the ovary. Four isoforms are expressed in previtellogenic to vitellogenic oocytes. In the huge nucleus of the oocyte, referred to as the germinal vesicle, CKIalphaS is dominant and CKIalphaL is expressed at a detectable level. Immunoblot analysis revealed that CKIalpha and CKIalphaS are major products in both immature and mature oocytes. These two isoforms were expressed in a tissue-dependent manner.
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Affiliation(s)
- Ryo Horiguchi
- Department of Molecular Biomechanics, Graduate University for Advanced Studies, Okazaki, 444-8585, Japan
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33
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Babu P, Deschenes RJ, Robinson LC. Akr1p-dependent Palmitoylation of Yck2p Yeast Casein Kinase 1 Is Necessary and Sufficient for Plasma Membrane Targeting. J Biol Chem 2004; 279:27138-47. [PMID: 15105419 DOI: 10.1074/jbc.m403071200] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
The Yck2 protein is a plasma membrane-associated casein kinase 1 isoform that attaches to membranes via palmitoylation of its C terminus. We have demonstrated that Yck2p traffics to the plasma membrane on secretory vesicles. Because Akr1p, the palmitoyl transferase for Yck2p, is located on Golgi membranes, it is likely that Yck2p first associates with Golgi membranes, and then is somehow recruited to budding plasma membrane-destined vesicles. We show here that residues 499-546 are sufficient for minimal Yck2p palmitoylation and plasma membrane localization. We previously described normal plasma membrane targeting of a Yck2p construct with the final five amino acids of Ras2p substituting for the final two Cys residues of Yck2p. This Yck2p variant no longer requires Akr1p for membrane association, but targets normally. We have generated the C-terminal deletions previously shown to affect Yck2p membrane association in this variant to determine which residues are important for targeting and/or modification. We find that all of the sequences previously identified as important for plasma membrane association are required only for Akr1p-dependent modification. Furthermore, palmitoylation is sufficient for specific association of Yck2p with secretory vesicles destined for the plasma membrane. Finally, both C-terminal Cys residues are palmitoylated, and dual acylation is required for efficient membrane association.
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Affiliation(s)
- Praveen Babu
- Department of Biochemistry and Molecular Biology, Louisiana State University Health Sciences Center, Shreveport, Louisiana 71130, USA
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34
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Cyert MS. Calcineurin signaling in Saccharomyces cerevisiae: how yeast go crazy in response to stress. Biochem Biophys Res Commun 2004; 311:1143-50. [PMID: 14623300 DOI: 10.1016/s0006-291x(03)01552-3] [Citation(s) in RCA: 273] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
In the yeast Saccharomyces cerevisiae, Ca(2+) signaling mediated by the Ca(2+)/calmodulin dependent phosphatase, calcineurin, is required for survival during environmental stress. One role of the phosphatase under these conditions is to activate gene expression through its regulation of the Crz1p ("crazy") transcription factor. Calcineurin dephosphorylates Crz1p and causes its rapid translocation from the cytosol to the nucleus. Crz1p then activates the transcription of genes whose products promote cell survival. Recent studies concerning the regulation of Crz1p by calcineurin are discussed in this review and the mechanisms by which calcineurin controls gene expression in yeast and mammalian cells are compared.
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Affiliation(s)
- Martha S Cyert
- Department of Biological Sciences, Stanford University, Stanford, CA 94306, USA.
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35
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Kafadar KA, Zhu H, Snyder M, Cyert MS. Negative regulation of calcineurin signaling by Hrr25p, a yeast homolog of casein kinase I. Genes Dev 2003; 17:2698-708. [PMID: 14597664 PMCID: PMC280619 DOI: 10.1101/gad.1140603] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Calcineurin is a Ca2+/calmodulin-regulated protein phosphatase required for Saccharomyces cerevisiae to respond to a variety of environmental stresses. Calcineurin promotes cell survival during stress by dephosphorylating and activating the Zn-finger transcription factor Crz1p/Tcn1p. Using a high-throughput assay, we screened 119 yeast kinases for their ability to phosphorylate Crz1p in vitro and identified the casein kinase I homolog Hrr25p. Here we show that Hrr25p negatively regulates Crz1p activity and nuclear localization in vivo. Hrr25p binds to and phosphorylates Crz1p in vitro and in vivo. Overexpression of Hrr25p decreases Crz1p-dependent transcription and antagonizes its Ca2+-induced nuclear accumulation. In the absence of Hrr25p, activation of Crz1p by Ca2+/calcineurin is potentiated. These findings represent the first identification of a negative regulator for Crz1p, and establish a novel physiological role for Hrr25p in antagonizing calcineurin signaling.
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Affiliation(s)
- Kimberly A Kafadar
- Department of Biological Sciences Stanford University, Stanford, California, 94305-5020, USA
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36
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Babu P, Bryan JD, Panek HR, Jordan SL, Forbrich BM, Kelley SC, Colvin RT, Robinson LC. Plasma membrane localization of the Yck2p yeast casein kinase 1 isoform requires the C-terminal extension and secretory pathway function. J Cell Sci 2002; 115:4957-68. [PMID: 12432082 DOI: 10.1242/jcs.00203] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The S. cerevisiae Yck2 protein is a plasma membrane-associated member of the casein kinase 1 protein kinase family that, with its homolog Yck1p, is required for bud morphogenesis, cytokinesis, endocytosis and other cellular processes. Membrane localization of Yckp is critical for its function, since soluble mutants do not provide sufficient biological activity to sustain normal growth. Yck2p has neither a predicted signal sequence nor obvious transmembrane domain to achieve its plasma membrane localization, but has a C-terminal -Cys-Cys sequence that is likely to be palmitoylated. We demonstrate here that Yck2p is targeted through association with vesicular intermediates of the classical secretory pathway. Yck2p lacking C-terminal Cys residues fails to associate with any membrane, whereas substitution of these residues with a farnesyl transferase signal sequence allows sec-dependent plasma membrane targeting and biological function, suggesting that modification is required for interaction with early secretory membranes but that targeting does not require a particular modification. Deletion analysis within the 185 residue C-terminus indicates that the final 28 residues are critical for membrane association, and additional sequences just upstream are required for proper plasma membrane targeting.
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Affiliation(s)
- Praveen Babu
- Department of Biochemistry and Molecular Biology, Louisiana State University Health Sciences Center, Shreveport, LA 71130, USA
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37
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Two novel doubletime mutants alter circadian properties and eliminate the delay between RNA and protein in Drosophila. J Neurosci 2001. [PMID: 11027213 DOI: 10.1523/jneurosci.20-20-07547.2000] [Citation(s) in RCA: 72] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Phosphorylation is an important feature of pacemaker organization in Drosophila. Genetic and biochemical evidence suggests involvement of the casein kinase I homolog doubletime (dbt) in the Drosophila circadian pacemaker. We have characterized two novel dbt mutants. Both cause a lengthening of behavioral period and profoundly alter period (per) and timeless (tim) transcript and protein profiles. The PER profile shows a major difference from the wild-type program only during the morning hours, consistent with a prominent role for DBT during the PER monomer degradation phase. The transcript profiles are delayed, but there is little effect on the protein accumulation profiles, resulting in the elimination of the characteristic lag between the mRNA and protein profiles. These results and others indicate that light and post-transcriptional regulation play major roles in defining the temporal properties of the protein curves and suggest that this lag is unnecessary for the feedback regulation of per and tim protein on per and tim transcription.
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38
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Suri V, Hall JC, Rosbash M. Two novel doubletime mutants alter circadian properties and eliminate the delay between RNA and protein in Drosophila. J Neurosci 2000; 20:7547-55. [PMID: 11027213 PMCID: PMC6772888] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/17/2023] Open
Abstract
Phosphorylation is an important feature of pacemaker organization in Drosophila. Genetic and biochemical evidence suggests involvement of the casein kinase I homolog doubletime (dbt) in the Drosophila circadian pacemaker. We have characterized two novel dbt mutants. Both cause a lengthening of behavioral period and profoundly alter period (per) and timeless (tim) transcript and protein profiles. The PER profile shows a major difference from the wild-type program only during the morning hours, consistent with a prominent role for DBT during the PER monomer degradation phase. The transcript profiles are delayed, but there is little effect on the protein accumulation profiles, resulting in the elimination of the characteristic lag between the mRNA and protein profiles. These results and others indicate that light and post-transcriptional regulation play major roles in defining the temporal properties of the protein curves and suggest that this lag is unnecessary for the feedback regulation of per and tim protein on per and tim transcription.
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Affiliation(s)
- V Suri
- Graduate Departments of Biochemistry and Biology, Howard Hughes Medical Institute, and National Science Foundation Center for Biological Timing, Brandeis University, Waltham, Massachusetts 02454, USA
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39
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Abstract
The Wnt signalling cascade is essential for the development of both invertebrates and vertebrates, and is altered during tumorigenesis. Although a general framework for Wnt signalling has been elucidated, not all of the components have been identified. Here we describe a serine kinase, casein kinase I (CKI), which was isolated by expression cloning in Xenopus embryos. CKI reproduces several properties of Wnt signals, including generation of complete dorsal axes, stabilization of beta-catenin and induction of genes that are direct targets of Wnt signals. Dominant-negative forms of CKI and a pharmacological blocker of CKI inhibited Wnt signals in Xenopus. Inhibiting CKI in Caenorhabditis elegans generated worms with a mom phenotype, indicative of a loss of Wnt signals. In addition, CKI bound to and increased the phosphorylation of dishevelled, a known component of the Wnt pathway. These data indicate that CKI may be a conserved component of the Wnt pathway.
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Affiliation(s)
- J M Peters
- Center for Developmental Biology, Department of Molecular Biology, UT Southwestern Medical Center, Dallas, Texas 75235-9133, USA.
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40
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Gross SD, Loijens JC, Anderson RA. The casein kinase Ialpha isoform is both physically positioned and functionally competent to regulate multiple events of mRNA metabolism. J Cell Sci 1999; 112 ( Pt 16):2647-56. [PMID: 10413673 DOI: 10.1242/jcs.112.16.2647] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Casein kinase I is a highly conserved family of serine/threonine protein kinases present in every organism tested from yeast to humans. To date, little is known about the function of the higher eukaryotic isoforms in this family. The CKI isoforms in Saccharomyces cerevisiae, however, have been genetically linked to the regulation of DNA repair, cell cycle progression and cytokinesis. It has also been established that the nuclear localization of two of these isoforms is essential for their function. The work presented here demonstrates that the higher eukaryotic CKIalpha isoform is also present within nuclei of certain established cell lines and associated with discrete nuclear structures. The nature of its nuclear localization was characterized. In this regard, CKIalpha was shown to colocalize with factors involved in pre-mRNA splicing at nuclear speckles and that its association with these structures exhibited several biochemical properties in common with known splicing factors. The kinase was also shown to be associated with a complex that contained certain splicing factors. Finally, in vitro, CKIalpha was shown to be capable of phosphorylating particular splicing factors within a region rich in serine/arginine dipeptide repeat motifs suggesting that it has both the opportunity and the capacity to regulate one or more steps of mRNA metabolism.
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Affiliation(s)
- S D Gross
- Department of Pharmacology, University of Wisconsin Medical School, Madison, WI, USA
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41
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Abstract
The first plant protein kinase sequences were reported as recently as 1989, but by mid-1998 there were more than 500, including 175 in Arabidopsis thaliana alone. Despite this impressive pace of discovery, progress in understanding the detailed functions of protein kinases in plants has been slower. Protein serine/threonine kinases from A. thaliana can be divided into around a dozen major groups based on their sequence relationships. For each of these groups, studies on animal and fungal homologs are briefly reviewed, and direct studies of their physiological functions in plants are then discussed in more detail. The network of protein-serine/threonine kinases in plant cells appears to act as a "central processor unit" (cpu), accepting input information from receptors that sense environmental conditions, phytohormones, and other external factors, and converting it into appropriate outputs such as changes in metabolism, gene expression, and cell growth and division.
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Affiliation(s)
- D. G. Hardie
- Biochemistry Department, Dundee University, Dundee, Scotland, DD1 5EH, United Kingdom; e-mail:
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42
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Murakami A, Kimura K, Nakano A. The inactive form of a yeast casein kinase I suppresses the secretory defect of the sec12 mutant. Implication of negative regulation by the Hrr25 kinase in the vesicle budding from the endoplasmic reticulum. J Biol Chem 1999; 274:3804-10. [PMID: 9920934 DOI: 10.1074/jbc.274.6.3804] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Sec12p is the guanine nucleotide exchange factor of Sar1 GTPase and functions at the very upstream in the vesicle budding reactions from the endoplasmic reticulum (ER). We previously identified three yeast loci, RST1, RST2, and RST3, whose mutations suppressed the temperature-sensitive growth of the sec12-4 mutant (Nakano, A. (1996) J. Biochem. (Tokyo) 120, 642-646). In the present study, we cloned the wild-type RST2 gene by complementation of the cold-sensitive phenotype of the rst2-1 mutant. RST2 turned out to be identical to HRR25, a gene encoding a dual-specificity casein kinase I in yeast. The rst2-1 mutation, which is now renamed hrr25-2, was due to the T176I amino acid replacement in the kinase domain. This mutation remedied not only the temperature-sensitive growth but also the defect of ER-to-Golgi protein transport of sec12. Immunoprecipitation of the hemagglutinin-tagged Hrr25-2 protein and a subsequent protein kinase assay showed that the kinase activity of the mutant protein was markedly reduced. The overproduction of another kinase-minus mutant of Hrr25p (Hrr25p K38A) slightly suppressed the growth defect of sec12-4 as well. These observations suggest that the reduction of the kinase activity in the mutant protein is important for the suppression of sec12. We propose that Hrr25p negatively regulates the vesicle budding from the ER.
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Affiliation(s)
- A Murakami
- Molecular Membrane Biology Laboratory, RIKEN, Wako, Saitama 351-0198, Japan
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43
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Gross SD, Anderson RA. Casein kinase I: spatial organization and positioning of a multifunctional protein kinase family. Cell Signal 1998; 10:699-711. [PMID: 9884021 DOI: 10.1016/s0898-6568(98)00042-4] [Citation(s) in RCA: 248] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
The casein kinase I family of serine/threonine protein kinases is highly conserved from yeast to humans. Until only recently, both the function and regulation of these enzymes remained poorly uncharacterised in that they appeared to be constitutively active and were capable of phosphorylating an untold number of other proteins. While relatively little was known regarding the exact function of the higher eukaryotic isoforms, the casein kinase I (CKI) isoforms from yeast have been genetically linked to vesicular trafficking, DNA repair, cell cycle progression and cytokinesis. All five S. cerevisiae isoforms are known to be associated with discrete cellular compartments and this localization has been shown to be absolutely essential for their respective functions. New evidence now suggests that the CKI isoforms in more complex systems also exhibit non-homogeneous subcellular distributions that may prove vital to defining the function and regulation of these enzymes. In particular, CKIalpha, the most-characterized vertebrate isoform, is associated with cytosolic vesicles, the mitotic spindle and structures within the nucleus. Functions associated with these localizations coincide with those previously reported in yeast, suggesting a conservation of function. Other reports have indicated that each of the remaining CKI isoforms have the capacity to make associations with components of several signal transduction pathways, thereby channeling CKI function toward specific regulatory events. This review will examine what is now known about the higher eukaryotic CKI family members from the perspective localization as a means of gaining a better understanding of the function and regulation of these kinases.
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Affiliation(s)
- S D Gross
- Department of Pharmacology, Howard Hughes Medical Institute, University of Colorado Health Sciences Center, Denver 80262, USA
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44
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Kitamura K, Yamashita I. Identification of a novel casein kinase-1 homolog in fission yeast Schizosaccharomyces pombe. Gene 1998; 214:131-7. [PMID: 9651503 DOI: 10.1016/s0378-1119(98)00203-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Fission yeast cells lacking either the ste9+- or rum1+ function cannot enter the cell differentiation pathway upon nutritional starvation. Sterility in both mutants is suppressed by the srs1-S41 mutation. A gene encoding a novel casein kinase-1 (CK1) isoform, cki3+, was isolated as a high-copy-number suppressor gene of the srs1 mutation. Cki3 protein is structurally more related to the Cki/Yck subfamily proteins than those of the Hhp/Hrr25 subfamily. A mutant cki3 gene in which a highly conserved lysine residue in the kinase subdomain II was substituted to arginine lost the ability to recover the growth defect in the srs1 mutant, indicating that catalytic activity was necessary for suppression. Gene disruption revealed that cki3+ was dispensable for cell viability, and cells lacking functional cki3+ exhibited no characteristic phenotype. Thus, S. pombe has three highly related CK1 isoforms (Cki1, Cki2 and Cki3), but none of them has an essential function.
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Affiliation(s)
- K Kitamura
- Center for Gene Science, Hiroshima University, Kagamiyama 1-4-2, Higashi-Hiroshima 739-8527, Japan.
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45
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Wojda I, Frajnt M, Jakubowicz T. The effect of heparin on the activity of Trichosporon cutaneum casein kinase I. J Basic Microbiol 1997; 37:371-7. [PMID: 9373951 DOI: 10.1002/jobm.3620370510] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Casein kinase I from Trichosporon cutaneum ribosome-free extracts was purified. Its molecular mass was calculated for 33 kDa. It was shown that casein, phosvitin and Trichosporon cutaneum ribosomal protein of 15 kDa were preferable substrates for the enzyme. It was found that heparin can stimulate or inhibit CKI activity depending on the substrate used. Stimulation of casein and inhibition of phosvitin phosphorylation was observed. In addition it was shown that ribosomal proteins of 19 kDa and 38 kDa were phosphorylated by CKI only in the presence of heparin.
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Affiliation(s)
- I Wojda
- Department of Molecular Biology, Institute of Microbiology and Biotechnology, Maria Curie-Skłodowska University, Akademicka, Poland.
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46
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Kitabayashi AN, Kusuda J, Hirai M, Hashimoto K. Cloning and chromosomal mapping of human casein kinase I gamma 2 (CSNK1G2). Genomics 1997; 46:133-7. [PMID: 9403068 DOI: 10.1006/geno.1997.4991] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
A clone of immature cDNA for human casein kinase I gamma 2 (CSNK1G2) was isolated by screening the human testis cDNA library with a PCR-amplified probe (about 400 bp) representing the kinase domain of rat casein kinase I gamma 2 (CKI gamma 2). Comparison of the entire sequence with that of rat CKI gamma 2 showed that the cDNA contained the complete coding sequence of CKI gamma 2 as well as an intron-like sequence of 1006 bp, part of which was homologous to the Alu sequence. To obtain an insertion-free CSNK1G2 cDNA, PCR cloning was performed based on the above sequence. The amplified 1687-bp fragment was subcloned and sequenced. The predicted amino acid sequence consisted of 416 residues, 94% of which were identical to that of the rat homologue. Although there are two Src homology 3 (SH3) domain-binding motifs (Pro-X-X-Pro consensus), Pro-Lys-Val-Pro and Pro-Ser-Glu-Pro in the C-terminal region of rat CKI gamma 2, only the latter was conserved in the human counterpart. This finding suggests that the latter motif is important for binding to the signal transduction adaptor protein Nck (NCK). The human CSNK1G2 gene was mapped to chromosome 19p13.3 by fluorescence in situ hybridization and PCR analysis of the human/rodent hybrid cell panel.
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Affiliation(s)
- A N Kitabayashi
- Division of Genetic Resources, National Institute of Infectious Diseases, Tokyo, Japan
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47
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Ho Y, Mason S, Kobayashi R, Hoekstra M, Andrews B. Role of the casein kinase I isoform, Hrr25, and the cell cycle-regulatory transcription factor, SBF, in the transcriptional response to DNA damage in Saccharomyces cerevisiae. Proc Natl Acad Sci U S A 1997; 94:581-6. [PMID: 9012827 PMCID: PMC19556 DOI: 10.1073/pnas.94.2.581] [Citation(s) in RCA: 91] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
In the budding yeast, Saccharomyces cerevisiae, DNA damage or ribonucleotide depletion causes the transcriptional induction of an array of genes with known or putative roles in DNA repair. The ATM-like kinase, Mec1, and the serine/threonine protein kinases, Rad53 and Dun1, are required for this transcriptional response. In this paper, we provide evidence suggesting that another kinase, Hrr25, is also involved in the transcriptional response to DNA damage through its interaction with the transcription factor, Swi6. The Swi6 protein interacts with Swi4 to form the SBF complex and with Mbp1 to form the MBF complex. SBF and MBF are required for the G1-specific expression of G1 cyclins and genes required for S-phase. We show that Swi6 associates with and is phosphorylated by Hrr25 in vitro. We find that swi4, swi6, and hrr25 mutants, but not mbp1 mutants, are sensitive to hydroxyurea and the DNA-damaging agent methyl methane-sulfonate and are defective in the transcriptional induction of a subset of DNA damage-inducible genes. Both the sensitivity of swi6 mutants to methyl methanesulfonate and hydroxyurea and the transcriptional defect of hrr25 mutants are rescued by overexpression of SWI4, implicating the SBF complex in the Hrr25/Swi6-dependent response to DNA damage.
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Affiliation(s)
- Y Ho
- Department of Molecular and Medical Genetics, University of Toronto, ON, Canada
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48
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Christenson E, DeMaggio AJ, Hockstra MF. The role of workhorse protein kinases in coordinating DNA metabolism and cell growth. Recent Results Cancer Res 1997; 143:263-74. [PMID: 8912426 DOI: 10.1007/978-3-642-60393-8_19] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
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49
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Wang X, Hoekstra MF, DeMaggio AJ, Dhillon N, Vancura A, Kuret J, Johnston GC, Singer RA. Prenylated isoforms of yeast casein kinase I, including the novel Yck3p, suppress the gcs1 blockage of cell proliferation from stationary phase. Mol Cell Biol 1996; 16:5375-85. [PMID: 8816449 PMCID: PMC231536 DOI: 10.1128/mcb.16.10.5375] [Citation(s) in RCA: 80] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
The GCS1 gene of the budding yeast Saccharomyces cerevisiae mediate the resumption of cell proliferation from the starved, stationary-phase state. Here we identify yeast genes that, in increased dosages, overcome the growth defect of gcs1 delta mutant cells. Among these are YCK1 (CK12) and YCK2 (CKI1), encoding membrane-associated casein kinase I, and YCK3, encoding a novel casein kinase I isoform. Some Yck3p gene product was found associated with the plasma membrane, like Yck1p and Yck2p, but most confractionated with the nucleus, like another yeast casein kinase I isoform, Hrr25p. Genetic studies showed that YCK3 and HRR25 constitute an essential gene family and that Yck3p can weakly substitute for Yck1p-Yck2p. For gcs1 delta suppression, both a protein kinase domain and a C-terminal prenylation motif were shown to be necessary. An impairment in endocytosis was found for gcs1 delta mutant cells, which was alleviated by an increased YCK2 gene dosage. The ability of an increased casein kinase I gene dosage to suppress the effects caused by the absence of Gcs1p suggests that Gcs1p and Yck1p-Yck2p affect parallel pathways.
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Affiliation(s)
- X Wang
- Department of Biochemistry, Dalhousie University, Halifax, Nova Scotia, Canada
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50
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Santos JA, Logarinho E, Tapia C, Allende CC, Allende JE, Sunkel CE. The casein kinase 1 alpha gene of Drosophila melanogaster is developmentally regulated and the kinase activity of the protein induced by DNA damage. J Cell Sci 1996; 109 ( Pt 7):1847-56. [PMID: 8832407 DOI: 10.1242/jcs.109.7.1847] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
We report the molecular cloning and characterisation of the first CK1(casein kinase) gene of Drosophila melanogaster (dmCK1). The protein sequence (DMCK1) shares significant homology with other mammalian CK1 protein kinases of the alpha sub-class. The dmCK1 gene is expressed only in adult females and during early embryonic development as a single transcript. Western blot analysis of total protein extracts of different stages of development show that the gene product is likewise present during early embryogenesis and in adult females. Kinase activity studies show that DMCK1 is active when in vitro translated but inactive when immunoprecipitated from total early embryo extracts. However, after dephosphorylation treatment the immunoprecipitates show high kinase activity. More significantly, DMCK1 kinase activity present in the immunoprecipitates can be specifically activated by gamma-irradiation of early embryos. Also, when DMCK1 is immunoprecipitated after irradiation it appears to undergo phosphorylation. Immunolocalization of DMCK1 in early embryos shows that the protein is predominantly cytoplasmic but after irradiation there is a significant relocalization to the interphase nucleus. The results suggest a possible requirement of the Drosophila CK1 alpha for mechanisms associated with DNA repair during early embryogenesis.
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Affiliation(s)
- J A Santos
- Centro de Citologia Experimental da Universidade do Porto, Portugal
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