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Kobayashi N, Katayama R, Minamoto K, Kawaguchi T, Tani S. C-terminus of serine-arginine protein kinase-like protein, SrpkF, is involved in conidiophore formation and hyphal growth under salt stress in Aspergillus aculeatus. Int Microbiol 2024; 27:91-100. [PMID: 37195349 DOI: 10.1007/s10123-023-00373-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2023] [Revised: 04/28/2023] [Accepted: 05/09/2023] [Indexed: 05/18/2023]
Abstract
The serine-arginine protein kinase-like protein, SrpkF, was identified as a regulator for the cellulose-responsive induction of cellulase genes in Aspergillus aculeatus. To analyze various aspects of SrpkF function, we examined the growth of the control strain (MR12); C-terminus deletion mutant, which produced SrpkF1-327 (ΔCsrpkF); whole gene-deletion mutant of srpkF (ΔsrpkF), srpkF overexpressing strain (OEsprkF); and the complemented strain (srpkF+) under various stress conditions. All test strains grew normally on minimal medium under control, high salt (1.5 M KCl), and high osmolality (2.0 M sorbitol and 1.0 M sucrose). However, only ΔCsrpkF showed reduced conidiation on 1.0 M NaCl media. Conidiation of ΔCsrpkF on 1.0 M NaCl media was reduced to 12% compared with that of srpkF+. Further, when OEsprkF and ΔCsrpkF were pre-cultured under salt stress conditions, germination under salt stress conditions was enhanced in both strains. By contrast, deletion of srpkF did not affect hyphal growth and conidiation under the same conditions. We then quantified the transcripts of the regulators involved in the central asexual conidiation pathway in A. aculeatus. The findings revealed that the expression of brlA, abaA, wetA, and vosA was reduced in ΔCsrpkF under salt stress. These data suggest that in A. aculeatus, SrpkF regulates conidiophore development. The C-terminus of SrpkF seems to be important for regulating SrpkF function in response to culture conditions such as salt stress.
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Affiliation(s)
- Natsumi Kobayashi
- Graduate School of Life and Environmental Sciences, Osaka Prefecture University, 1-1 Gakuen-cho, Sakai, 599-8531, Japan
| | - Ryohei Katayama
- Graduate School of Life and Environmental Sciences, Osaka Prefecture University, 1-1 Gakuen-cho, Sakai, 599-8531, Japan
| | - Kentaro Minamoto
- Graduate School of Agriculture, Osaka Metropolitan University, 1-1 Gakuen-cho, Sakai, 599-8531, Japan
| | - Takashi Kawaguchi
- Graduate School of Life and Environmental Sciences, Osaka Prefecture University, 1-1 Gakuen-cho, Sakai, 599-8531, Japan
- Graduate School of Agriculture, Osaka Metropolitan University, 1-1 Gakuen-cho, Sakai, 599-8531, Japan
| | - Shuji Tani
- Graduate School of Life and Environmental Sciences, Osaka Prefecture University, 1-1 Gakuen-cho, Sakai, 599-8531, Japan.
- Graduate School of Agriculture, Osaka Metropolitan University, 1-1 Gakuen-cho, Sakai, 599-8531, Japan.
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2
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Hogg EKJ, Findlay GM. Functions of SRPK, CLK and DYRK kinases in stem cells, development, and human developmental disorders. FEBS Lett 2023; 597:2375-2415. [PMID: 37607329 PMCID: PMC10952393 DOI: 10.1002/1873-3468.14723] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2023] [Revised: 07/08/2023] [Accepted: 07/18/2023] [Indexed: 08/24/2023]
Abstract
Human developmental disorders encompass a wide range of debilitating physical conditions and intellectual disabilities. Perturbation of protein kinase signalling underlies the development of some of these disorders. For example, disrupted SRPK signalling is associated with intellectual disabilities, and the gene dosage of DYRKs can dictate the pathology of disorders including Down's syndrome. Here, we review the emerging roles of the CMGC kinase families SRPK, CLK, DYRK, and sub-family HIPK during embryonic development and in developmental disorders. In particular, SRPK, CLK, and DYRK kinase families have key roles in developmental signalling and stem cell regulation, and can co-ordinate neuronal development and function. Genetic studies in model organisms reveal critical phenotypes including embryonic lethality, sterility, musculoskeletal errors, and most notably, altered neurological behaviours arising from defects of the neuroectoderm and altered neuronal signalling. Further unpicking the mechanisms of specific kinases using human stem cell models of neuronal differentiation and function will improve our understanding of human developmental disorders and may provide avenues for therapeutic strategies.
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Affiliation(s)
- Elizabeth K. J. Hogg
- The MRC Protein Phosphorylation and Ubiquitylation Unit, School of Life SciencesUniversity of DundeeUK
| | - Greg M. Findlay
- The MRC Protein Phosphorylation and Ubiquitylation Unit, School of Life SciencesUniversity of DundeeUK
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3
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Pimentel DC, Leopoldo JR, Teixeira LF, Barros MVDA, de Souza APM, Onofre TS, de Carvalho RL, Machado SA, Messias IG, Pinto CCDS, Poleto MD, Diogo MA, Mariotini-Moura C, Bressan GC, Teixeira RR, Fietto JLR, Vasconcellos RDS. First evidence of a serine arginine protein kinase (SRPK) in leishmania braziliensis and its potential as therapeutic target. Acta Trop 2023; 238:106801. [PMID: 36563831 DOI: 10.1016/j.actatropica.2022.106801] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2022] [Revised: 12/17/2022] [Accepted: 12/19/2022] [Indexed: 12/24/2022]
Abstract
Leishmaniasis is a parasitic disease found in tropical and subtropical regions around the world, caused by parasites of the genus Leishmania. The disease is a public health concern and presents clinical manifestations that can cause death, disability, and mutilation. The parasite has promastigote (vector) and amastigote (vertebrate host) forms and kinase enzymes are involved in this differentiation process. In the present investigation, we show, for the first time, evidence of a serine/arginine protein kinase in Leshmania braziliensis (LbSRPK). Our results show that amastigotes express more LbSRPK than promastigotes. Analogues of SRPIN340 (a known inhibitor of SRPK) were evaluated for their leishmanicidal activity and two of them, namely SRVIC22 and SRVIC32 showed important leishmanicidal activity in vitro. SRVIC22 and SRVIC32 were able to reduce the infection rate in macrophages and the number of intracellular amastigotes by 55 and 60%, respectively. Bioinformatics analysis revealed the existence of two different amino acid residues in the active site of LbSRPK compared to their human homologue (Tyr/Leu-and Ser/Tyr), which could explain the absence of leishmanicidal activity of SRPIN340 on infected macrophages. In order to enhance leishmanicidal activity of the analogues, optimizations were proposed in the structures of the ligands, suggesting strong interactions with the catalytic site of LbSRPK. Although the evidence on the action of inhibitors upon LbSRPK is only indirect, our studies not only reveal, for the first time, evidence of a SRPK in Leishmania, but also shed light on a new therapeutic target for drug development.
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Affiliation(s)
- Débora Cristina Pimentel
- Departamento de Bioquímica e Biologia Molecular, Universidade Federal de Viçosa, Av. P. H. Rolfs, s/n, Campus Universitário, CEP, Viçosa, MG 36570-900, Brazil
| | - Juliana Rodrigues Leopoldo
- Departamento de Bioquímica e Biologia Molecular, Universidade Federal de Viçosa, Av. P. H. Rolfs, s/n, Campus Universitário, CEP, Viçosa, MG 36570-900, Brazil
| | - Leilane Ferreira Teixeira
- Departamento de Bioquímica e Biologia Molecular, Universidade Federal de Viçosa, Av. P. H. Rolfs, s/n, Campus Universitário, CEP, Viçosa, MG 36570-900, Brazil
| | - Marcus Vinícius de Andrade Barros
- Departamento de Química, Universidade Federal de Viçosa, Av. P. H. Rolfs, s/n, Campus Universitário, CEP, Viçosa, MG 36570-900, Brazil
| | - Ana Paula Martins de Souza
- Departamento de Química, Universidade Federal de Viçosa, Av. P. H. Rolfs, s/n, Campus Universitário, CEP, Viçosa, MG 36570-900, Brazil
| | - Thiago Souza Onofre
- Department of Microbiology and Molecular Genetics, McGovern Medical School, University of Texas Health Science Center at Houston, Houston, Texas, USA
| | - Rayane Luiza de Carvalho
- Departamento de Bioquímica e Biologia Molecular, Universidade Federal de Viçosa, Av. P. H. Rolfs, s/n, Campus Universitário, CEP, Viçosa, MG 36570-900, Brazil
| | - Sara Andrade Machado
- Departamento de Bioquímica e Biologia Molecular, Universidade Federal de Viçosa, Av. P. H. Rolfs, s/n, Campus Universitário, CEP, Viçosa, MG 36570-900, Brazil
| | - Isabelly Gonçalves Messias
- Departamento de Bioquímica e Biologia Molecular, Universidade Federal de Viçosa, Av. P. H. Rolfs, s/n, Campus Universitário, CEP, Viçosa, MG 36570-900, Brazil
| | - Carla Cristina de Souza Pinto
- Departamento de Bioquímica e Biologia Molecular, Universidade Federal de Viçosa, Av. P. H. Rolfs, s/n, Campus Universitário, CEP, Viçosa, MG 36570-900, Brazil
| | - Marcelo Depolo Poleto
- Departamento de Bioquímica e Biologia Molecular, Universidade Federal de Viçosa, Av. P. H. Rolfs, s/n, Campus Universitário, CEP, Viçosa, MG 36570-900, Brazil
| | - Marcel Arruda Diogo
- Departamento de Bioquímica e Biologia Molecular, Universidade Federal de Viçosa, Av. P. H. Rolfs, s/n, Campus Universitário, CEP, Viçosa, MG 36570-900, Brazil
| | - Christiane Mariotini-Moura
- FAMINAS Muriaé, Bairro Universitário Muriaé, Av. Cristiano Ferreira Varella, 655, CEP, MG 36888-233, Brazil
| | - Gustavo Costa Bressan
- Departamento de Bioquímica e Biologia Molecular, Universidade Federal de Viçosa, Av. P. H. Rolfs, s/n, Campus Universitário, CEP, Viçosa, MG 36570-900, Brazil
| | - Robson Ricardo Teixeira
- Departamento de Química, Universidade Federal de Viçosa, Av. P. H. Rolfs, s/n, Campus Universitário, CEP, Viçosa, MG 36570-900, Brazil
| | - Juliana Lopes Rangel Fietto
- Departamento de Bioquímica e Biologia Molecular, Universidade Federal de Viçosa, Av. P. H. Rolfs, s/n, Campus Universitário, CEP, Viçosa, MG 36570-900, Brazil
| | - Raphael de Souza Vasconcellos
- Departamento de Bioquímica e Biologia Molecular, Universidade Federal de Viçosa, Av. P. H. Rolfs, s/n, Campus Universitário, CEP, Viçosa, MG 36570-900, Brazil.
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López-Palacios TP, Andersen JL. Kinase regulation by liquid–liquid phase separation. Trends Cell Biol 2022:S0962-8924(22)00260-4. [DOI: 10.1016/j.tcb.2022.11.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2022] [Revised: 11/23/2022] [Accepted: 11/24/2022] [Indexed: 12/23/2022]
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Hutchinson KM, Hunn JC, Reines D. Nab3 nuclear granule accumulation is driven by respiratory capacity. Curr Genet 2022; 68:581-591. [PMID: 35922525 PMCID: PMC9887517 DOI: 10.1007/s00294-022-01248-w] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2022] [Revised: 07/18/2022] [Accepted: 07/20/2022] [Indexed: 02/02/2023]
Abstract
Numerous biological processes involve proteins capable of transiently assembling into subcellular compartments necessary for cellular functions. One process is the RNA polymerase II transcription cycle which involves initiation, elongation, co-transcriptional modification of nascent RNA, and termination. The essential yeast transcription termination factor Nab3 is required for termination of small non-coding RNAs and accumulates into a compact nuclear granule upon glucose removal. Nab3 nuclear granule accumulation varies in penetrance across yeast strains and a higher Nab3 granule accumulation phenotype is associated with petite strains, suggesting a possible ATP-dependent mechanism for granule disassembly. Here, we demonstrate the uncoupling of mitochondrial oxidative phosphorylation by drug treatment or deletions of nuclear-encoded ATP synthase subunit genes were sufficient to increase Nab3 granule accumulation and led to an inability to proliferate during prolonged glucose deprivation, which requires respiration. Additionally, by enriching for respiration competent cells from a petite-prone strain, we generated a low granule-accumulating strain from a relatively high one, providing another link between respiratory competency and Nab3 granules. Consistent with the resulting idea that ATP is involved in granule accumulation, the addition of extracellular ATP to semi-permeabilized cells was sufficient to reduce Nab3 granule accumulation. Deleting the SKY1 gene, which encodes a kinase that phosphorylates nuclear SR repeat-containing proteins and is involved in efficient stress granule disassembly, also resulted in increased granule accumulation. This observation implicates Sky1 in Nab3 granule biogenesis. Taken together, these findings suggest there is normally an equilibrium between termination factor granule assembly and disassembly mediated by ATP-requiring nuclear machinery.
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Affiliation(s)
| | - Jeremy C Hunn
- Department of Biochemistry, Emory University School of Medicine, Atlanta, GA, USA
| | - Daniel Reines
- Department of Biochemistry, Emory University School of Medicine, Atlanta, GA, USA.
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6
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Rodriguez Gallo MC, Li Q, Mehta D, Uhrig RG. Genome-scale analysis of Arabidopsis splicing-related protein kinase families reveals roles in abiotic stress adaptation. BMC PLANT BIOLOGY 2022; 22:496. [PMID: 36273172 PMCID: PMC9587599 DOI: 10.1186/s12870-022-03870-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/25/2022] [Accepted: 10/04/2022] [Indexed: 05/24/2023]
Abstract
Nearly 60 - 80 % of intron-containing plant genes undergo alternative splicing in response to either stress or plant developmental cues. RNA splicing is performed by a large ribonucleoprotein complex called the spliceosome in conjunction with associated subunits such as serine arginine (SR) proteins, all of which undergo extensive phosphorylation. In plants, there are three main protein kinase families suggested to phosphorylate core spliceosome subunits and related splicing factors based on orthology to human splicing-related kinases: the SERINE/ARGININE PROTEIN KINASES (SRPK), ARABIDOPSIS FUS3 COMPLEMENT (AFC), and Pre-mRNA PROCESSING FACTOR 4 (PRP4K) protein kinases. To better define the conservation and role(s) of these kinases in plants, we performed a genome-scale analysis of the three families across photosynthetic eukaryotes, followed by extensive transcriptomic and bioinformatic analysis of all Arabidopsis thaliana SRPK, AFC, and PRP4K protein kinases to elucidate their biological functions. Unexpectedly, this revealed the existence of SRPK and AFC phylogenetic groups with distinct promoter elements and patterns of transcriptional response to abiotic stress, while PRP4Ks possess no phylogenetic sub-divisions, suggestive of functional redundancy. We also reveal splicing-related kinase families are both diel and photoperiod regulated, implicating different orthologs as discrete time-of-day RNA splicing regulators. This foundational work establishes a number of new hypotheses regarding how reversible spliceosome phosphorylation contributes to both diel plant cell regulation and abiotic stress adaptation in plants.
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Affiliation(s)
- M C Rodriguez Gallo
- Department of Biological Sciences, University of Alberta, Edmonton, AB, T6G 2E9, Canada
| | - Q Li
- Department of Biological Sciences, University of Alberta, Edmonton, AB, T6G 2E9, Canada
| | - D Mehta
- Department of Biological Sciences, University of Alberta, Edmonton, AB, T6G 2E9, Canada
| | - R G Uhrig
- Department of Biological Sciences, University of Alberta, Edmonton, AB, T6G 2E9, Canada.
- Department of Biochemistry, University of Alberta, Edmonton, AB, Canada.
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Nikolakaki E, Sigala I, Giannakouros T. Good Cop, Bad Cop: The Different Roles of SRPKs. Front Genet 2022; 13:902718. [PMID: 35719374 PMCID: PMC9202992 DOI: 10.3389/fgene.2022.902718] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2022] [Accepted: 05/05/2022] [Indexed: 12/21/2022] Open
Abstract
SR Protein Kinases (SRPKs), discovered approximately 30 years ago, are widely known as splice factor kinases due to their decisive involvement in the regulation of various steps of mRNA splicing. However, they were also shown to regulate diverse cellular activities by phosphorylation of serine residues residing in serine-arginine/arginine-serine dipeptide motifs. Over the last decade, SRPK1 has been reported as both tumor suppressor and promoter, depending on the cellular context and has been implicated in both chemotherapy sensitivity and resistance. Moreover, SRPK2 has been reported to exhibit contradictory functions in different cell contexts promoting either apoptosis or tumor growth. The aim of the current review is to broaden and deepen our understanding of the SRPK function focusing on the subcellular localization of the kinases. There is ample evidence that the balance between cytoplasmic and nuclear SRPK levels is tightly regulated and determines cell response to external signals. Specific cell states coupled to kinase levels, spatial specific interactions with substrates but also changes in the extent of phosphorylation that allow SRPKs to exhibit a rheostat-like control on their substrates, could decide the proliferative or antiproliferative role of SRPKs.
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8
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Serine-Arginine Protein Kinase 1 (SRPK1): a systematic review of its multimodal role in oncogenesis. Mol Cell Biochem 2022; 477:2451-2467. [PMID: 35583632 PMCID: PMC9499919 DOI: 10.1007/s11010-022-04456-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2021] [Accepted: 04/27/2022] [Indexed: 11/13/2022]
Abstract
Alternative splicing is implicated in each of the hallmarks of cancer, and is mechanised by various splicing factors. Serine-Arginine Protein Kinase 1 (SRPK1) is an enzyme which moderates the activity of splicing factors rich in serine/arginine domains. Here we review SRPK1’s relationship with various cancers by performing a systematic review of all relevant published data. Elevated SRPK1 expression correlates with advanced disease stage and poor survival in many epithelial derived cancers. Numerous pre-clinical studies investigating a host of different tumour types; have found increased SRPK1 expression to be associated with proliferation, invasion, migration and apoptosis in vitro as well as tumour growth, tumourigenicity and metastasis in vivo. Aberrant SRPK1 expression is implicated in various signalling pathways associated with oncogenesis, a number of which, such as the PI3K/AKT, NF-КB and TGF-Beta pathway, are implicated in multiple different cancers. SRPK1-targeting micro RNAs have been identified in a number of studies and shown to have an important role in regulating SRPK1 activity. SRPK1 expression is also closely related to the response of various tumours to platinum-based chemotherapeutic agents. Future clinical applications will likely focus on the role of SRPK1 as a biomarker of treatment resistance and the potential role of its inhibition.
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Brandt P, Gerwien F, Wagner L, Krüger T, Ramírez-Zavala B, Mirhakkak MH, Schäuble S, Kniemeyer O, Panagiotou G, Brakhage AA, Morschhäuser J, Vylkova S. Candida albicans SR-Like Protein Kinases Regulate Different Cellular Processes: Sky1 Is Involved in Control of Ion Homeostasis, While Sky2 Is Important for Dipeptide Utilization. Front Cell Infect Microbiol 2022; 12:850531. [PMID: 35601106 PMCID: PMC9121809 DOI: 10.3389/fcimb.2022.850531] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2022] [Accepted: 03/24/2022] [Indexed: 01/21/2023] Open
Abstract
Protein kinases play a crucial role in regulating cellular processes such as growth, proliferation, environmental adaptation and stress responses. Serine-arginine (SR) protein kinases are highly conserved in eukaryotes and regulate fundamental processes such as constitutive and alternative splicing, mRNA processing and ion homeostasis. The Candida albicans genome encodes two (Sky1, Sky2) and the Candida glabrata genome has one homolog (Sky1) of the human SR protein kinase 1, but their functions have not yet been investigated. We used deletion strains of the corresponding genes in both fungi to study their cellular functions. C. glabrata and C. albicans strains lacking SKY1 exhibited higher resistance to osmotic stress and toxic polyamine concentrations, similar to Saccharomyces cerevisiae sky1Δ mutants. Deletion of SKY2 in C. albicans resulted in impaired utilization of various dipeptides as the sole nitrogen source. Subsequent phosphoproteomic analysis identified the di- and tripeptide transporter Ptr22 as a potential Sky2 substrate. Sky2 seems to be involved in Ptr22 regulation since overexpression of PTR22 in the sky2Δ mutant restored the ability to grow on dipeptides and made the cells more susceptible to the dipeptide antifungals Polyoxin D and Nikkomycin Z. Altogether, our results demonstrate that C. albicans and C. glabrata Sky1 protein kinases are functionally similar to Sky1 in S. cerevisiae, whereas C. albicans Sky2, a unique kinase of the CTG clade, likely regulates dipeptide uptake via Ptr22.
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Affiliation(s)
- Philipp Brandt
- Septomics Research Center, Friedrich Schiller University and Leibniz Institute for Natural Product Research and Infection Biology – Hans Knöll Institute, Jena, Germany
| | - Franziska Gerwien
- Septomics Research Center, Friedrich Schiller University and Leibniz Institute for Natural Product Research and Infection Biology – Hans Knöll Institute, Jena, Germany
| | - Lysett Wagner
- Septomics Research Center, Friedrich Schiller University and Leibniz Institute for Natural Product Research and Infection Biology – Hans Knöll Institute, Jena, Germany
| | - Thomas Krüger
- Molecular and Applied Microbiology, Leibniz Institute for Natural Product Research and Infection Biology – Hans Knöll Institute, Jena, Germany
| | | | - Mohammad H. Mirhakkak
- Systems Biology and Bioinformatics, Leibniz Institute for Natural Product Research and Infection Biology – Hans Knöll Institute, Jena, Germany
| | - Sascha Schäuble
- Systems Biology and Bioinformatics, Leibniz Institute for Natural Product Research and Infection Biology – Hans Knöll Institute, Jena, Germany
| | - Olaf Kniemeyer
- Molecular and Applied Microbiology, Leibniz Institute for Natural Product Research and Infection Biology – Hans Knöll Institute, Jena, Germany
| | - Gianni Panagiotou
- Systems Biology and Bioinformatics, Leibniz Institute for Natural Product Research and Infection Biology – Hans Knöll Institute, Jena, Germany
- Department of Medicine and State Key Laboratory of Pharmaceutical Biotechnology, University of Hong Kong, Hong Kong, Hong Kong SAR, China
| | - Axel A. Brakhage
- Molecular and Applied Microbiology, Leibniz Institute for Natural Product Research and Infection Biology – Hans Knöll Institute, Jena, Germany
| | - Joachim Morschhäuser
- Institute for Molecular Infection Biology, University of Würzburg, Würzburg, Germany
| | - Slavena Vylkova
- Septomics Research Center, Friedrich Schiller University and Leibniz Institute for Natural Product Research and Infection Biology – Hans Knöll Institute, Jena, Germany
- *Correspondence: Slavena Vylkova,
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An ATM/CHK2 Signaling Pathway Induces Nuclear Translocation of SRPK2 in Cisplatin-Treated HeLa Cells. Processes (Basel) 2021. [DOI: 10.3390/pr9122223] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Chemotherapeutic agents are frequently used to treat various cancers, but the mechanisms mediating the cellular response to the drugs are still not fully understood. We previously reported that the nuclear translocation of serine/arginine protein kinases (SRPKs), triggered by the exposure of cells to DNA damage-inducers, plays a pivotal role in drug responsiveness. Here, we investigated the mechanism linking the nuclear accumulation of SRPK2 to the cisplatin treatment of HeLa cells. We present experimental evidence that nuclear SRPK2 acts downstream of Chk2 in the ATM/Chk2 cascade. The inhibition of ATM or Chk2 kinase activity by specific low-molecular-weight inhibitors restricted SRPK2 to the cytoplasm and conferred tolerance to cisplatin treatment. A similar effect was achieved by treating cells with SRPIN340, a selective SRPK1/2 inhibitor, thus confirming previous findings that kinase activity is indispensable for the nuclear import of SRPKs. These data add to previous findings that support a decisive role of SRPKs in coordinating cellular response to DNA damage.
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Lu YY, Krebber H. Nuclear mRNA Quality Control and Cytoplasmic NMD Are Linked by the Guard Proteins Gbp2 and Hrb1. Int J Mol Sci 2021; 22:ijms222011275. [PMID: 34681934 PMCID: PMC8541090 DOI: 10.3390/ijms222011275] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2021] [Revised: 10/13/2021] [Accepted: 10/17/2021] [Indexed: 12/23/2022] Open
Abstract
Pre-mRNA splicing is critical for cells, as defects in this process can lead to altered open reading frames and defective proteins, potentially causing neurodegenerative diseases and cancer. Introns are removed in the nucleus and splicing is documented by the addition of exon-junction-complexes (EJCs) at exon-exon boundaries. This “memory” of splicing events is important for the ribosome, which translates the RNAs in the cytoplasm. In case a stop codon was detected before an EJC, translation is blocked and the RNA is eliminated by the nonsense-mediated decay (NMD). In the model organism Saccharomyces cerevisiae, two guard proteins, Gbp2 and Hrb1, have been identified as nuclear quality control factors for splicing. In their absence, intron-containing mRNAs leak into the cytoplasm. Their presence retains transcripts until the process is completed and they release the mRNAs by recruitment of the export factor Mex67. On transcripts that experience splicing problems, these guard proteins recruit the nuclear RNA degradation machinery. Interestingly, they continue their quality control function on exported transcripts. They support NMD by inhibiting translation and recruiting the cytoplasmic degradation factors. In this way, they link the nuclear and cytoplasmic quality control systems. These discoveries are also intriguing for humans, as homologues of these guard proteins are present also in multicellular organisms. Here, we provide an overview of the quality control mechanisms of pre-mRNA splicing, and present Gbp2 and Hrb1, as well as their human counterparts, as important players in these pathways.
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Cascarina SM, Kaplan JP, Elder MR, Brookbank L, Ross ED. Generalizable Compositional Features Influencing the Proteostatic Fates of Polar Low-Complexity Domains. Int J Mol Sci 2021; 22:ijms22168944. [PMID: 34445649 PMCID: PMC8396281 DOI: 10.3390/ijms22168944] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2021] [Revised: 08/11/2021] [Accepted: 08/16/2021] [Indexed: 11/25/2022] Open
Abstract
Protein aggregation is associated with a growing list of human diseases. A substantial fraction of proteins in eukaryotic proteomes constitutes a proteostasis network—a collection of proteins that work together to maintain properly folded proteins. One of the overarching functions of the proteostasis network is the prevention or reversal of protein aggregation. How proteins aggregate in spite of the anti-aggregation activity of the proteostasis machinery is incompletely understood. Exposed hydrophobic patches can trigger degradation by the ubiquitin-proteasome system, a key branch of the proteostasis network. However, in a recent study, we found that model glycine (G)-rich or glutamine/asparagine (Q/N)-rich prion-like domains differ in their susceptibility to detection and degradation by this system. Here, we expand upon this work by examining whether the features controlling the degradation of our model prion-like domains generalize broadly to G-rich and Q/N-rich domains. Experimentally, native yeast G-rich domains in isolation are sensitive to the degradation-promoting effects of hydrophobic residues, whereas native Q/N-rich domains completely resist these effects and tend to aggregate instead. Bioinformatic analyses indicate that native G-rich domains from yeast and humans tend to avoid degradation-promoting features, suggesting that the proteostasis network may act as a form of selection at the molecular level that constrains the sequence space accessible to G-rich domains. However, the sensitivity or resistance of G-rich and Q/N-rich domains, respectively, was not always preserved in their native protein contexts, highlighting that proteins can evolve other sequence features to overcome the intrinsic sensitivity of some LCDs to degradation.
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Sigala I, Koutroumani M, Koukiali A, Giannakouros T, Nikolakaki E. Nuclear Translocation of SRPKs Is Associated with 5-FU and Cisplatin Sensitivity in HeLa and T24 Cells. Cells 2021; 10:cells10040759. [PMID: 33808326 PMCID: PMC8065462 DOI: 10.3390/cells10040759] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2021] [Revised: 03/24/2021] [Accepted: 03/26/2021] [Indexed: 11/16/2022] Open
Abstract
Serine/arginine protein kinases (SRPKs) phosphorylate Arg/Ser dipeptide-containing proteins that play crucial roles in a broad spectrum of basic cellular processes. The existence of a large internal spacer sequence that separates the bipartite kinase catalytic core and anchors the kinases in the cytoplasm is a unique structural feature of SRPKs. Here, we report that exposure of HeLa and T24 cells to DNA damage inducers triggers the nuclear translocation of SRPK1 and SRPK2. Furthermore, we show that nuclear SRPKs did not protect from, but on the contrary, mediated the cytotoxic effects of genotoxic agents, such as 5-fluorouracil (5-FU) and cisplatin. Confirming previous data showing that the kinase activity is essential for the entry of SRPKs into the nucleus, SRPIN340, a selective SRPK1/2 inhibitor, blocked the nuclear accumulation of the kinases, thus diminishing the cytotoxic effects of the drugs. ATR/ATM-dependent phosphorylation of threonine 326 and serine 408 in the spacer domain of SRPK1 was essential for the redistribution of the kinase to the nucleus. Substitution of either of these two residues to alanine or inhibition of ATR/ATM kinase activity abolished nuclear localization of SRPK1 and conferred tolerance to 5-FU treatment. These findings suggest that SRPKs may play an important role in linking cellular signaling to DNA damage in eukaryotic cells.
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Affiliation(s)
- Ioanna Sigala
- Laboratory of Biochemistry, Department of Chemistry, Aristotelian University, 54124 Thessaloniki, Greece; (I.S.); (A.K.); (T.G.)
| | - Maria Koutroumani
- Centre for Research and Technology-Hellas, Institute of Applied Biosciences, 57001 Thessaloniki, Greece;
| | - Anastasia Koukiali
- Laboratory of Biochemistry, Department of Chemistry, Aristotelian University, 54124 Thessaloniki, Greece; (I.S.); (A.K.); (T.G.)
| | - Thomas Giannakouros
- Laboratory of Biochemistry, Department of Chemistry, Aristotelian University, 54124 Thessaloniki, Greece; (I.S.); (A.K.); (T.G.)
| | - Eleni Nikolakaki
- Laboratory of Biochemistry, Department of Chemistry, Aristotelian University, 54124 Thessaloniki, Greece; (I.S.); (A.K.); (T.G.)
- Correspondence:
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14
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Bustos F, Segarra-Fas A, Nardocci G, Cassidy A, Antico O, Davidson L, Brandenburg L, Macartney TJ, Toth R, Hastie CJ, Moran J, Gourlay R, Varghese J, Soares RF, Montecino M, Findlay GM. Functional Diversification of SRSF Protein Kinase to Control Ubiquitin-Dependent Neurodevelopmental Signaling. Dev Cell 2020; 55:629-647.e7. [PMID: 33080171 PMCID: PMC7725506 DOI: 10.1016/j.devcel.2020.09.025] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2020] [Revised: 08/17/2020] [Accepted: 09/25/2020] [Indexed: 02/06/2023]
Abstract
Conserved protein kinases with core cellular functions have been frequently redeployed during metazoan evolution to regulate specialized developmental processes. The Ser/Arg (SR)-rich splicing factor (SRSF) protein kinase (SRPK), which is implicated in splicing regulation, is one such conserved eukaryotic kinase. Surprisingly, we show that SRPK has acquired the capacity to control a neurodevelopmental ubiquitin signaling pathway. In mammalian embryonic stem cells and cultured neurons, SRPK phosphorylates Ser-Arg motifs in RNF12/RLIM, a key developmental E3 ubiquitin ligase that is mutated in an intellectual disability syndrome. Processive phosphorylation by SRPK stimulates RNF12-dependent ubiquitylation of nuclear transcription factor substrates, thereby acting to restrain a neural gene expression program that is aberrantly expressed in intellectual disability. SRPK family genes are also mutated in intellectual disability disorders, and patient-derived SRPK point mutations impair RNF12 phosphorylation. Our data reveal unappreciated functional diversification of SRPK to regulate ubiquitin signaling that ensures correct regulation of neurodevelopmental gene expression.
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Affiliation(s)
- Francisco Bustos
- The MRC Protein Phosphorylation and Ubiquitylation Unit, School of Life Sciences, the University of Dundee, Dundee DD1 5EH, UK
| | - Anna Segarra-Fas
- The MRC Protein Phosphorylation and Ubiquitylation Unit, School of Life Sciences, the University of Dundee, Dundee DD1 5EH, UK
| | - Gino Nardocci
- Institute of Biomedical Sciences and FONDAP Center for Genome Regulation, Universidad Andrés Bello, Santiago, Chile
| | - Andrew Cassidy
- Tayside Centre for Genomic Analysis, School of Medicine, University of Dundee, Dundee DD1 9SY, UK
| | - Odetta Antico
- The MRC Protein Phosphorylation and Ubiquitylation Unit, School of Life Sciences, the University of Dundee, Dundee DD1 5EH, UK
| | - Lindsay Davidson
- School of Life Sciences, The University of Dundee, Dundee DD1 5EH, UK
| | - Lennart Brandenburg
- The MRC Protein Phosphorylation and Ubiquitylation Unit, School of Life Sciences, the University of Dundee, Dundee DD1 5EH, UK
| | - Thomas J Macartney
- The MRC Protein Phosphorylation and Ubiquitylation Unit, School of Life Sciences, the University of Dundee, Dundee DD1 5EH, UK
| | - Rachel Toth
- The MRC Protein Phosphorylation and Ubiquitylation Unit, School of Life Sciences, the University of Dundee, Dundee DD1 5EH, UK
| | - C James Hastie
- The MRC Protein Phosphorylation and Ubiquitylation Unit, School of Life Sciences, the University of Dundee, Dundee DD1 5EH, UK
| | - Jennifer Moran
- The MRC Protein Phosphorylation and Ubiquitylation Unit, School of Life Sciences, the University of Dundee, Dundee DD1 5EH, UK
| | - Robert Gourlay
- The MRC Protein Phosphorylation and Ubiquitylation Unit, School of Life Sciences, the University of Dundee, Dundee DD1 5EH, UK
| | - Joby Varghese
- The MRC Protein Phosphorylation and Ubiquitylation Unit, School of Life Sciences, the University of Dundee, Dundee DD1 5EH, UK
| | - Renata F Soares
- The MRC Protein Phosphorylation and Ubiquitylation Unit, School of Life Sciences, the University of Dundee, Dundee DD1 5EH, UK
| | - Martin Montecino
- Institute of Biomedical Sciences and FONDAP Center for Genome Regulation, Universidad Andrés Bello, Santiago, Chile
| | - Greg M Findlay
- The MRC Protein Phosphorylation and Ubiquitylation Unit, School of Life Sciences, the University of Dundee, Dundee DD1 5EH, UK.
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15
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The genome of opportunistic fungal pathogen Fusarium oxysporum carries a unique set of lineage-specific chromosomes. Commun Biol 2020; 3:50. [PMID: 32005944 PMCID: PMC6994591 DOI: 10.1038/s42003-020-0770-2] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2019] [Accepted: 01/10/2020] [Indexed: 12/12/2022] Open
Abstract
Fusarium oxysporum is a cross-kingdom fungal pathogen that infects plants and humans. Horizontally transferred lineage-specific (LS) chromosomes were reported to determine host-specific pathogenicity among phytopathogenic F. oxysporum. However, the existence and functional importance of LS chromosomes among human pathogenic isolates are unknown. Here we report four unique LS chromosomes in a human pathogenic strain NRRL 32931, isolated from a leukemia patient. These LS chromosomes were devoid of housekeeping genes, but were significantly enriched in genes encoding metal ion transporters and cation transporters. Homologs of NRRL 32931 LS genes, including a homolog of ceruloplasmin and the genes that contribute to the expansion of the alkaline pH-responsive transcription factor PacC/Rim1p, were also present in the genome of NRRL 47514, a strain associated with Fusarium keratitis outbreak. This study provides the first evidence, to our knowledge, for genomic compartmentalization in two human pathogenic fungal genomes and suggests an important role of LS chromosomes in niche adaptation. Zhang, Yang et al. compare a Fusarium oxysporum isolate obtained clinically to a phytopathogenic strain to examine transfer of lineage-specific chromosomes in determining host specificity. They find four unique lineage-specific chromosomes that seem to contribute to fungal adaptation to human hosts.
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16
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Crosstalk of Phosphorylation and Arginine Methylation in Disordered SRGG Repeats of Saccharomyces cerevisiae Fibrillarin and Its Association with Nucleolar Localization. J Mol Biol 2020; 432:448-466. [DOI: 10.1016/j.jmb.2019.11.006] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2019] [Revised: 10/18/2019] [Accepted: 11/05/2019] [Indexed: 11/19/2022]
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17
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Shattuck JE, Cascarina SM, Paul KR, Ross ED. Sky1: at the intersection of prion-like proteins and stress granule regulation. Curr Genet 2019; 66:463-468. [PMID: 31745569 DOI: 10.1007/s00294-019-01044-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2019] [Revised: 11/05/2019] [Accepted: 11/06/2019] [Indexed: 02/03/2023]
Abstract
Serine-arginine (SR) protein kinases regulate diverse cellular activities, including various steps in RNA maturation and transport. The yeast Saccharomyces cerevisiae expresses a single SR kinase, Sky1. Sky1 has a bipartite kinase domain, separated by an aggregation-prone prion-like domain (PrLD). The assembly of PrLDs is involved in the formation of various membraneless organelles, including stress granules; stress granules are reversible ribonucleoprotein assemblies that form in response to a variety of stresses. Here, we review a recent study suggesting that Sky1's PrLD promotes Sky1 recruitment to stress granules, and that Sky1 regulates stress granule dissolution by phosphorylating the RNA-shuttling protein Npl3.
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Affiliation(s)
- Jenifer E Shattuck
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, CO, 80523, USA
| | - Sean M Cascarina
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, CO, 80523, USA
| | - Kacy R Paul
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, CO, 80523, USA
| | - Eric D Ross
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, CO, 80523, USA.
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18
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Shattuck JE, Paul KR, Cascarina SM, Ross ED. The prion-like protein kinase Sky1 is required for efficient stress granule disassembly. Nat Commun 2019; 10:3614. [PMID: 31399582 PMCID: PMC6688984 DOI: 10.1038/s41467-019-11550-w] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2018] [Accepted: 07/19/2019] [Indexed: 01/14/2023] Open
Abstract
Stress granules are membraneless protein- and mRNA-rich organelles that form in response to perturbations in environmental conditions. Stress granule formation is reversible, and persistent stress granules have been implicated in a variety of neurodegenerative disorders, including amyotrophic lateral sclerosis. However, characterization of the factors involved in dissolving stress granules is incomplete. Many stress granule proteins contain prion-like domains (PrLDs), some of which have been linked to stress granule formation. Here, we demonstrate that the PrLD-containing yeast protein kinase Sky1 is a stress granule component. Sky1 is recruited to stress granules in part via its PrLD, and Sky1's kinase activity regulates timely stress granule disassembly during stress recovery. This effect is mediated by phosphorylation of the stress granule component Npl3. Sky1 can compensate for defects in chaperone-mediated stress granule disassembly and vice-versa, demonstrating that cells have multiple overlapping mechanisms for re-solubilizing stress granule components.
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Affiliation(s)
- Jenifer E Shattuck
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, CO, 80523, USA
- Department of Pharmacology and Experimental Therapeutics, Boston University School of Medicine, Boston, MA, 02118, USA
| | - Kacy R Paul
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, CO, 80523, USA
| | - Sean M Cascarina
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, CO, 80523, USA
| | - Eric D Ross
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, CO, 80523, USA.
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19
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Iacovella MG, Bremang M, Basha O, Giacò L, Carotenuto W, Golfieri C, Szakal B, Dal Maschio M, Infantino V, Beznoussenko GV, Joseph CR, Visintin C, Mironov AA, Visintin R, Branzei D, Ferreira-Cerca S, Yeger-Lotem E, De Wulf P. Integrating Rio1 activities discloses its nutrient-activated network in Saccharomyces cerevisiae. Nucleic Acids Res 2019; 46:7586-7611. [PMID: 30011030 PMCID: PMC6125641 DOI: 10.1093/nar/gky618] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2018] [Accepted: 06/28/2018] [Indexed: 12/14/2022] Open
Abstract
The Saccharomyces cerevisiae kinase/adenosine triphosphatase Rio1 regulates rDNA transcription and segregation, pre-rRNA processing and small ribosomal subunit maturation. Other roles are unknown. When overexpressed, human ortholog RIOK1 drives tumor growth and metastasis. Likewise, RIOK1 promotes 40S ribosomal subunit biogenesis and has not been characterized globally. We show that Rio1 manages directly and via a series of regulators, an essential signaling network at the protein, chromatin and RNA levels. Rio1 orchestrates growth and division depending on resource availability, in parallel to the nutrient-activated Tor1 kinase. To define the Rio1 network, we identified its physical interactors, profiled its target genes/transcripts, mapped its chromatin-binding sites and integrated our data with yeast’s protein–protein and protein–DNA interaction catalogs using network computation. We experimentally confirmed network components and localized Rio1 also to mitochondria and vacuoles. Via its network, Rio1 commands protein synthesis (ribosomal gene expression, assembly and activity) and turnover (26S proteasome expression), and impinges on metabolic, energy-production and cell-cycle programs. We find that Rio1 activity is conserved to humans and propose that pathological RIOK1 may fuel promiscuous transcription, ribosome production, chromosomal instability, unrestrained metabolism and proliferation; established contributors to cancer. Our study will advance the understanding of numerous processes, here revealed to depend on Rio1 activity.
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Affiliation(s)
- Maria G Iacovella
- Department of Experimental Oncology, European Institute of Oncology, Via Adamello 16, 20139 Milan, Italy
| | - Michael Bremang
- Department of Experimental Oncology, European Institute of Oncology, Via Adamello 16, 20139 Milan, Italy.,Current address: Proteome Sciences Plc, Hamilton House, Mabledon Place, London, United Kingdom
| | - Omer Basha
- Department of Clinical Biochemistry and Pharmacology, Faculty of Health Sciences and the National Institute for Biotechnology in the Negev, Ben-Gurion University of the Negev, POB 653, Beer-Sheva 84105, Israel
| | - Luciano Giacò
- Department of Experimental Oncology, European Institute of Oncology, Via Adamello 16, 20139 Milan, Italy
| | - Walter Carotenuto
- The FIRC Institute of Molecular Oncology (IFOM), Via Adamello 16, 20139 Milan, Italy
| | - Cristina Golfieri
- Department of Experimental Oncology, European Institute of Oncology, Via Adamello 16, 20139 Milan, Italy
| | - Barnabas Szakal
- The FIRC Institute of Molecular Oncology (IFOM), Via Adamello 16, 20139 Milan, Italy
| | - Marianna Dal Maschio
- Department of Experimental Oncology, European Institute of Oncology, Via Adamello 16, 20139 Milan, Italy
| | - Valentina Infantino
- Department of Experimental Oncology, European Institute of Oncology, Via Adamello 16, 20139 Milan, Italy
| | - Galina V Beznoussenko
- The FIRC Institute of Molecular Oncology (IFOM), Via Adamello 16, 20139 Milan, Italy
| | - Chinnu R Joseph
- The FIRC Institute of Molecular Oncology (IFOM), Via Adamello 16, 20139 Milan, Italy
| | - Clara Visintin
- Department of Experimental Oncology, European Institute of Oncology, Via Adamello 16, 20139 Milan, Italy
| | - Alexander A Mironov
- The FIRC Institute of Molecular Oncology (IFOM), Via Adamello 16, 20139 Milan, Italy
| | - Rosella Visintin
- Department of Experimental Oncology, European Institute of Oncology, Via Adamello 16, 20139 Milan, Italy
| | - Dana Branzei
- The FIRC Institute of Molecular Oncology (IFOM), Via Adamello 16, 20139 Milan, Italy.,Istituto di Genetica Molecolare, Consiglio Nazionale delle Ricerche (CNR), Via Abbiategrasso 207, 27100 Pavia, Italy
| | - Sébastien Ferreira-Cerca
- Lehrstuhl für Biochemie III, Universität Regensburg, Universitätsstraße 31, 93053 Regensburg, Germany
| | - Esti Yeger-Lotem
- Department of Clinical Biochemistry and Pharmacology, Faculty of Health Sciences and the National Institute for Biotechnology in the Negev, Ben-Gurion University of the Negev, POB 653, Beer-Sheva 84105, Israel
| | - Peter De Wulf
- Department of Experimental Oncology, European Institute of Oncology, Via Adamello 16, 20139 Milan, Italy.,Centre for Integrative Biology (CIBIO), University of Trento, Via Sommarive 9, 38123 Trento, Italy
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20
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Kumar P, Kundu D, Mondal AK, Nain V, Puria R. Inhibition of TOR signalling in lea1 mutant induces apoptosis in Saccharomyces cerevisiae. ANN MICROBIOL 2019. [DOI: 10.1007/s13213-018-1422-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
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21
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Patel M, Sachidanandan M, Adnan M. Serine arginine protein kinase 1 (SRPK1): a moonlighting protein with theranostic ability in cancer prevention. Mol Biol Rep 2018; 46:1487-1497. [PMID: 30535769 DOI: 10.1007/s11033-018-4545-5] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2018] [Accepted: 11/30/2018] [Indexed: 12/15/2022]
Abstract
Serine/arginine protein kinase 1 (SRPK1); a versatile functional moonlighting protein involved in varied cellular activities comprised of cell cycle progression, innate immune response, chromatin reorganization, negative and positive regulation of viral genome replication, protein amino acid phosphorylation, regulation of numerous mRNA-processing pathways, germ cell development as well as inflammation due to acquaintances with many transcription factors and signaling pathways. Several diseases including cancer have been associated with dysregulation of SRPK1. The function of SRPK1 in cancer is contradictory and inexplicable because it acts as both tumor suppressor and promoter based on the type of cell and locale. Over expression of SRPK1 including its role has been recently narrated and associated with several cancers, which includes, lung, glioma, prostate and breast via dysregulated signals from the Akt/eIF4E/HIF-1/VEGF, Erk or MAPK, PI3K/AKT/mTOR, TGF-β, and Wnt/β-catenin signaling pathways. Therefore, SRPK1 has occurred as a promising and possible curative target in cancer. In recent years, few natural and synthetic SRPK1 inhibitors have been discovered. This review emphasizes and highlights the complicated connections between SRPK1 and oncogenic signaling circuits together with the possibility of aiming SRPK1 in the treatment of cancer.
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Affiliation(s)
- Mitesh Patel
- Department of Biosciences, Bapalal Vaidya Botanical Research Centre, Veer Narmad South Gujarat University, Surat, Gujarat, India
| | - Manojkumar Sachidanandan
- Department of Oral Radiology, College of Dentistry, University of Hail, P O Box 2440, Hail, Saudi Arabia
| | - Mohd Adnan
- Department of Biology, Faculty of Science, University of Hail, P O Box 2440, Hail, Saudi Arabia.
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22
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Wang G, Sun P, Gong Z, Gu L, Lou Y, Fang W, Zhang L, Su L, Yang T, Wang B, Zhou J, Xu JR, Wang Z, Zheng W. Srk1 kinase, a SR protein-specific kinase, is important for sexual reproduction, plant infection and pre-mRNA processing in Fusarium graminearum. Environ Microbiol 2018; 20:3261-3277. [DOI: 10.1111/1462-2920.14299] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2018] [Revised: 05/24/2018] [Accepted: 05/26/2018] [Indexed: 11/28/2022]
Affiliation(s)
- Guanghui Wang
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops; College of Plant Protection, Fujian Agriculture and Forestry University; Fuzhou China
- Institute of Oceanography; Minjiang University; Fuzhou China
| | - Peng Sun
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops; College of Plant Protection, Fujian Agriculture and Forestry University; Fuzhou China
| | - Ziwen Gong
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops; College of Plant Protection, Fujian Agriculture and Forestry University; Fuzhou China
| | - Lianfeng Gu
- Basic Forestry and Proteomics Center (BFPC), Haixia Institute of Science and Technology; Fujian Agriculture and Forestry University; Fuzhou China
| | - Yi Lou
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops; College of Plant Protection, Fujian Agriculture and Forestry University; Fuzhou China
| | - Wenqin Fang
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops; College of Plant Protection, Fujian Agriculture and Forestry University; Fuzhou China
| | - Lianhu Zhang
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops; College of Plant Protection, Fujian Agriculture and Forestry University; Fuzhou China
| | - Li Su
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops; College of Plant Protection, Fujian Agriculture and Forestry University; Fuzhou China
| | - Tao Yang
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops; College of Plant Protection, Fujian Agriculture and Forestry University; Fuzhou China
| | - Baohua Wang
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops; College of Plant Protection, Fujian Agriculture and Forestry University; Fuzhou China
| | - Jie Zhou
- Fujian Province Key Laboratory of Pathogenic Fungi and Mycotoxins; College of Life Sciences, Fujian Agriculture and Forestry University; Fuzhou China
| | - Jin-Rong Xu
- State Key Laboratory of Crop Stress Biology for Arid Areas; College of Plant Protection, Northwest A&F University; Yangling Shaanxi China
| | - Zonghua Wang
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops; College of Plant Protection, Fujian Agriculture and Forestry University; Fuzhou China
- Institute of Oceanography; Minjiang University; Fuzhou China
| | - Wenhui Zheng
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops; College of Plant Protection, Fujian Agriculture and Forestry University; Fuzhou China
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23
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Kinome Expansion in the Fusarium oxysporum Species Complex Driven by Accessory Chromosomes. mSphere 2018; 3:3/3/e00231-18. [PMID: 29898984 PMCID: PMC6001611 DOI: 10.1128/msphere.00231-18] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2018] [Accepted: 05/23/2018] [Indexed: 12/23/2022] Open
Abstract
Isolates of Fusarium oxysporum are adapted to survive a wide range of host and nonhost conditions. In addition, F. oxysporum was recently recognized as the top emerging opportunistic fungal pathogen infecting immunocompromised humans. The sensory and response networks of these fungi undoubtedly play a fundamental role in establishing the adaptability of this group. We have examined the kinomes of 12 F. oxysporum isolates and highlighted kinase families that distinguish F. oxysporum from other fungi, as well as different isolates from one another. The amplification of kinases involved in environmental signal relay and regulating downstream cellular responses clearly sets Fusarium apart from other Ascomycetes. Although the functions of many of these kinases are still unclear, their specific proliferation highlights them as a result of the evolutionary forces that have shaped this species complex and clearly marks them as targets for exploitation in order to combat disease. The Fusarium oxysporum species complex (FOSC) is a group of soilborne pathogens causing severe disease in more than 100 plant hosts, while individual strains exhibit strong host specificity. Both chromosome transfer and comparative genomics experiments have demonstrated that lineage-specific (LS) chromosomes contribute to the host-specific pathogenicity. However, little is known about the functional importance of genes encoded in these LS chromosomes. Focusing on signaling transduction, this study compared the kinomes of 12 F. oxysporum isolates, including both plant and human pathogens and 1 nonpathogenic biocontrol strain, with 7 additional publicly available ascomycete genomes. Overall, F. oxysporum kinomes are the largest, facilitated in part by the acquisitions of the LS chromosomes. The comparative study identified 99 kinases that are present in almost all examined fungal genomes, forming the core signaling network of ascomycete fungi. Compared to the conserved ascomycete kinome, the expansion of the F. oxysporum kinome occurs in several kinase families such as histidine kinases that are involved in environmental signal sensing and target of rapamycin (TOR) kinase that mediates cellular responses. Comparative kinome analysis suggests a convergent evolution that shapes individual F. oxysporum isolates with an enhanced and unique capacity for environmental perception and associated downstream responses. IMPORTANCE Isolates of Fusarium oxysporum are adapted to survive a wide range of host and nonhost conditions. In addition, F. oxysporum was recently recognized as the top emerging opportunistic fungal pathogen infecting immunocompromised humans. The sensory and response networks of these fungi undoubtedly play a fundamental role in establishing the adaptability of this group. We have examined the kinomes of 12 F. oxysporum isolates and highlighted kinase families that distinguish F. oxysporum from other fungi, as well as different isolates from one another. The amplification of kinases involved in environmental signal relay and regulating downstream cellular responses clearly sets Fusarium apart from other Ascomycetes. Although the functions of many of these kinases are still unclear, their specific proliferation highlights them as a result of the evolutionary forces that have shaped this species complex and clearly marks them as targets for exploitation in order to combat disease.
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24
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Hatcher JM, Wu G, Zeng C, Zhu J, Meng F, Patel S, Wang W, Ficarro SB, Leggett AL, Powell CE, Marto JA, Zhang K, Ngo JCK, Fu XD, Zhang T, Gray NS. SRPKIN-1: A Covalent SRPK1/2 Inhibitor that Potently Converts VEGF from Pro-angiogenic to Anti-angiogenic Isoform. Cell Chem Biol 2018; 25:460-470.e6. [PMID: 29478907 PMCID: PMC5973797 DOI: 10.1016/j.chembiol.2018.01.013] [Citation(s) in RCA: 84] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2017] [Revised: 11/03/2017] [Accepted: 01/26/2018] [Indexed: 01/07/2023]
Abstract
The SRPK family of kinases regulates pre-mRNA splicing by phosphorylating serine/arginine (SR)-rich splicing factors, signals splicing control in response to extracellular stimuli, and contributes to tumorigenesis, suggesting that these splicing kinases are potential therapeutic targets. Here, we report the development of the first irreversible SRPK inhibitor, SRPKIN-1, which is also the first kinase inhibitor that forms a covalent bond with a tyrosine phenol group in the ATP-binding pocket. Kinome-wide profiling demonstrates its selectivity for SRPK1/2, and SRPKIN-1 attenuates SR protein phosphorylation at submicromolar concentrations. Vascular endothelial growth factor (VEGF) is a known target for SRPK-regulated splicing and, relative to the first-generation SRPK inhibitor SRPIN340 or small interfering RNA-mediated SRPK knockdown, SRPKIN-1 is more potent in converting the pro-angiogenic VEGF-A165a to the anti-angiogenic VEGF-A165b isoform and in blocking laser-induced neovascularization in a murine retinal model. These findings encourage further development of SRPK inhibitors for treatment of age-related macular degeneration.
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Affiliation(s)
- John M. Hatcher
- Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, MA 02115, USA,Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115, USA
| | - Guowei Wu
- Department of Cellular and Molecular Medicine, Institute of Genomic Medicine, University of California, San Diego, La Jolla, CA 92093, USA
| | - Chuyue Zeng
- School of Life Sciences, The Chinese University of Hong Kong, Shatin, Hong Kong Special Administrative Region NA, China
| | - Jie Zhu
- Shiley Eye Institute, Institute for Engineering in Medicine, Institute for Genomic Medicine, University of California, San Diego, La Jolla, CA 92093, USA,Guangzhou Women and Children’s Medical Center, Guangzhou Medical University, Guangzhou 510623, China
| | - Fan Meng
- Department of Cellular and Molecular Medicine, Institute of Genomic Medicine, University of California, San Diego, La Jolla, CA 92093, USA
| | - Sherrina Patel
- Shiley Eye Institute, Institute for Engineering in Medicine, Institute for Genomic Medicine, University of California, San Diego, La Jolla, CA 92093, USA
| | - Wenqiu Wang
- Shiley Eye Institute, Institute for Engineering in Medicine, Institute for Genomic Medicine, University of California, San Diego, La Jolla, CA 92093, USA
| | - Scott B. Ficarro
- Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, MA 02115, USA,Department of Oncologic Pathology and Blais Proteomics Center, Dana-Farber Cancer Institute, Boston, MA 02115, USA,Department of Pathology, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Alan L. Leggett
- Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, MA 02115, USA
| | - Chelsea E. Powell
- Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, MA 02115, USA,Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115, USA
| | - Jarrod A. Marto
- Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, MA 02115, USA,Department of Oncologic Pathology and Blais Proteomics Center, Dana-Farber Cancer Institute, Boston, MA 02115, USA,Department of Pathology, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Kang Zhang
- Shiley Eye Institute, Institute for Engineering in Medicine, Institute for Genomic Medicine, University of California, San Diego, La Jolla, CA 92093, USA
| | - Jacky Chi Ki Ngo
- School of Life Sciences, The Chinese University of Hong Kong, Shatin, Hong Kong Special Administrative Region NA, China
| | - Xiang-Dong Fu
- Department of Cellular and Molecular Medicine, Institute of Genomic Medicine, University of California, San Diego, La Jolla, CA 92093, USA,Correspondence: (X.-D.F.), (T.Z.), (N.S.G.)
| | - Tinghu Zhang
- Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, MA 02115, USA,Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115, USA,Correspondence: (X.-D.F.), (T.Z.), (N.S.G.)
| | - Nathanael S. Gray
- Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, MA 02115, USA,Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115, USA,Correspondence: (X.-D.F.), (T.Z.), (N.S.G.)
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Muddukrishna B, Jackson CA, Yu MC. Protein arginine methylation of Npl3 promotes splicing of the SUS1 intron harboring non-consensus 5' splice site and branch site. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2017; 1860:730-739. [PMID: 28392442 DOI: 10.1016/j.bbagrm.2017.04.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/07/2016] [Revised: 03/20/2017] [Accepted: 04/04/2017] [Indexed: 11/18/2022]
Abstract
Protein arginine methylation occurs on spliceosomal components and spliceosome-associated proteins, but how this modification contributes to their function in pre-mRNA splicing remains sparse. Here we provide evidence that protein arginine methylation of the yeast SR-/hnRNP-like protein Npl3 plays a role in facilitating efficient splicing of the SUS1 intron that harbors a non-consensus 5' splice site and branch site. In yeast cells lacking the major protein arginine methyltransferase HMT1, we observed a change in the co-transcriptional recruitment of the U1 snRNP subunit Snp1 and Npl3 to pre-mRNAs harboring both consensus (ECM33 and ASC1) and non-consensus (SUS1) 5' splice site and branch site. Using an Npl3 mutant that phenocopies wild-type Npl3 when expressed in Δhmt1 cells, we showed that the arginine methylation of Npl3 is responsible for this. Examination of pre-mRNA splicing efficiency in these mutants reveals the requirement of Npl3 methylation for the efficient splicing of SUS1 intron 1, but not of ECM33 or ASC1. Changing the 5' splice site and branch site in SUS1 intron 1 to the consensus form restored splicing efficiency in an Hmt1-independent manner. Results from biochemical studies show that methylation of Npl3 promotes its optimal association with the U1 snRNP through its association with the U1 snRNP subunit Mud1. Based on these data, we propose a model in which Hmt1, via arginine methylation of Npl3, facilitates U1 snRNP engagement with the pre-mRNA to promote usage of non-consensus splice sites by the splicing machinery.
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Affiliation(s)
- Bhavana Muddukrishna
- Department of Biological Sciences, State University of New York at Buffalo, Buffalo, NY, United States
| | - Christopher A Jackson
- Department of Biological Sciences, State University of New York at Buffalo, Buffalo, NY, United States
| | - Michael C Yu
- Department of Biological Sciences, State University of New York at Buffalo, Buffalo, NY, United States.
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26
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Koutroumani M, Papadopoulos GE, Vlassi M, Nikolakaki E, Giannakouros T. Evidence for disulfide bonds in SR Protein Kinase 1 (SRPK1) that are required for activity and nuclear localization. PLoS One 2017; 12:e0171328. [PMID: 28166275 PMCID: PMC5293202 DOI: 10.1371/journal.pone.0171328] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2016] [Accepted: 01/18/2017] [Indexed: 11/18/2022] Open
Abstract
Serine/arginine protein kinases (SRPKs) phosphorylate Arg/Ser dipeptide-containing proteins that play crucial roles in a broad spectrum of basic cellular processes. The existence of a large internal spacer sequence that separates the bipartite kinase catalytic core is a unique structural feature of SRPKs. Previous structural studies on a catalytically active fragment of SRPK1, which lacks the main part of the spacer domain, revealed that SRPK1 remains in an active state without any post-translational modifications or specific intra-protein interactions, while the spacer domain is depicted as a loop structure, outside the kinase core. Using systematic mutagenesis we now provide evidence that replacement of any individual cysteine residue in the spacer, apart from Cys414, or in its proximal flaking ends of the two kinase catalytic domains has an impact on kinase activity. Furthermore, the cysteine residues are critical for nuclear translocation of SRPK1 in response to genotoxic stress and SRPK1-dependent splicing of a reporter gene. While replacement of Cys207, Cys502 and Cys539 of the catalytic domains is predicted to distort the kinase active structure, our findings suggest that Cys356, Cys386, Cys427 and Cys455 of the spacer domain and Cys188 of the first catalytic domain are engaged in disulfide bridging. We propose that such a network of intramolecular disulfide bonds mediates the bending of the spacer region thus allowing the proximal positioning of the two catalytic subunits which is a prerequisite for SRPK1 activity.
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Affiliation(s)
- Maria Koutroumani
- Laboratory of Biochemistry, Department of Chemistry, Aristotle University, Thessaloniki, Greece
| | | | - Metaxia Vlassi
- Institute of Biosciences & Applications, National Centre for Scientific Research "Demokritos", Athens, Greece
| | - Eleni Nikolakaki
- Laboratory of Biochemistry, Department of Chemistry, Aristotle University, Thessaloniki, Greece
- * E-mail: (TG); (EN)
| | - Thomas Giannakouros
- Laboratory of Biochemistry, Department of Chemistry, Aristotle University, Thessaloniki, Greece
- * E-mail: (TG); (EN)
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27
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Plank M, Fischer R, Geoghegan V, Charles PD, Konietzny R, Acuto O, Pears C, Schofield CJ, Kessler BM. Expanding the yeast protein arginine methylome. Proteomics 2015; 15:3232-43. [DOI: 10.1002/pmic.201500032] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2015] [Revised: 03/27/2015] [Accepted: 06/02/2015] [Indexed: 11/07/2022]
Affiliation(s)
- Michael Plank
- Target Discovery Institute; Nuffield Department of Medicine; University of Oxford; Oxford UK
- Chemistry Research Laboratory; University of Oxford; Oxford UK
| | - Roman Fischer
- Target Discovery Institute; Nuffield Department of Medicine; University of Oxford; Oxford UK
| | - Vincent Geoghegan
- Sir William Dunn School of Pathology; University of Oxford; Oxford UK
| | - Philip D. Charles
- Target Discovery Institute; Nuffield Department of Medicine; University of Oxford; Oxford UK
| | - Rebecca Konietzny
- Target Discovery Institute; Nuffield Department of Medicine; University of Oxford; Oxford UK
| | - Oreste Acuto
- Sir William Dunn School of Pathology; University of Oxford; Oxford UK
| | | | | | - Benedikt M. Kessler
- Target Discovery Institute; Nuffield Department of Medicine; University of Oxford; Oxford UK
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28
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Cheng Y, Wang X, Yao J, Voegele RT, Zhang Y, Wang W, Huang L, Kang Z. Characterization of protein kinase PsSRPKL, a novel pathogenicity factor in the wheat stripe rust fungus. Environ Microbiol 2015; 17:2601-17. [PMID: 25407954 DOI: 10.1111/1462-2920.12719] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2014] [Revised: 11/09/2014] [Accepted: 11/10/2014] [Indexed: 12/31/2022]
Abstract
As in other eukaryotes, protein kinases (PKs) are generally evolutionarily conserved and play major regulatory roles in plant pathogenic fungi. Many PKs have been proven to be important for pathogenesis in model fungal plant pathogens, but little is currently known about their roles in the pathogenesis of cereal rust fungi, devastating pathogens in agriculture worldwide. Here, we report on an in planta highly induced PK gene PsSRPKL from the wheat stripe rust fungus Puccinia striiformis f. sp. tritici (Pst), one of the most important cereal rust fungi. PsSRPKL belongs to a group of PKs that are evolutionarily specific to cereal rust fungi. It shows a high level of intraspecies polymorphism in the kinase domains and directed green fluorescent protein chimers to plant nuclei. Overexpression of PsSRPKL in fission yeast induces aberrant cell morphology and a decreased resistance to environmental stresses. Most importantly, PsSRPKL is proven to be an important pathogenicity factor responsible for fungal growth and responses to environmental stresses, therefore contributing significantly to Pst virulence in wheat. We hypothesize that cereal rust fungi have developed specific PKs as pathogenicity factors for adaptation to their host species during evolution. Thus, our findings provide significant insights into pathogenicity and virulence evolution in cereal rust fungi.
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Affiliation(s)
- Yulin Cheng
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Plant Protection, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - Xiaojie Wang
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Plant Protection, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - Juanni Yao
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Plant Protection, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - Ralf T Voegele
- Fachgebiet Phytopathologie, Fakultät Agrarwissenschaften, Institut für Phytomedizin, Universität Hohenheim, Stuttgart, Germany
| | - Yanru Zhang
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Plant Protection, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - Wumei Wang
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Plant Protection, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - Lili Huang
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Plant Protection, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - Zhensheng Kang
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Plant Protection, Northwest A&F University, Yangling, Shaanxi, 712100, China
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29
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Kern S, Agarwal S, Huber K, Gehring AP, Strödke B, Wirth CC, Brügl T, Abodo LO, Dandekar T, Doerig C, Fischer R, Tobin AB, Alam MM, Bracher F, Pradel G. Inhibition of the SR protein-phosphorylating CLK kinases of Plasmodium falciparum impairs blood stage replication and malaria transmission. PLoS One 2014; 9:e105732. [PMID: 25188378 PMCID: PMC4154858 DOI: 10.1371/journal.pone.0105732] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2013] [Accepted: 07/28/2014] [Indexed: 01/01/2023] Open
Abstract
Cyclin-dependent kinase-like kinases (CLKs) are dual specificity protein kinases that phosphorylate Serine/Arginine-rich (SR) proteins involved in pre-mRNA processing. Four CLKs, termed PfCLK-1-4, can be identified in the human malaria parasite Plasmodium falciparum, which show homology with the yeast SR protein kinase Sky1p. The four PfCLKs are present in the nucleus and cytoplasm of the asexual blood stages and of gametocytes, sexual precursor cells crucial for malaria parasite transmission from humans to mosquitoes. We identified three plasmodial SR proteins, PfSRSF12, PfSFRS4 and PfSF-1, which are predominantly present in the nucleus of blood stage trophozoites, PfSRSF12 and PfSF-1 are further detectable in the nucleus of gametocytes. We found that recombinantly expressed SR proteins comprising the Arginine/Serine (RS)-rich domains were phosphorylated by the four PfCLKs in in vitro kinase assays, while a recombinant PfSF-1 peptide lacking the RS-rich domain was not phosphorylated. Since it was hitherto not possible to knock-out the pfclk genes by conventional gene disruption, we aimed at chemical knock-outs for phenotype analysis. We identified five human CLK inhibitors, belonging to the oxo-β-carbolines and aminopyrimidines, as well as the antiseptic chlorhexidine as PfCLK-targeting compounds. The six inhibitors block P. falciparum blood stage replication in the low micromolar to nanomolar range by preventing the trophozoite-to-schizont transformation. In addition, the inhibitors impair gametocyte maturation and gametogenesis in in vitro assays. The combined data show that the four PfCLKs are involved in phosphorylation of SR proteins with essential functions for the blood and sexual stages of the malaria parasite, thus pointing to the kinases as promising targets for antimalarial and transmission blocking drugs.
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Affiliation(s)
- Selina Kern
- Research Center for Infectious Diseases, University of Würzburg, Würzburg, Germany
- Institute of Molecular Biotechnology, RWTH Aachen University, Aachen, Germany
| | - Shruti Agarwal
- Research Center for Infectious Diseases, University of Würzburg, Würzburg, Germany
| | - Kilian Huber
- Department of Pharmacy – Center for Drug Research, Ludwig-Maximillians University, Munich, Germany
| | - André P. Gehring
- Department of Pharmacy – Center for Drug Research, Ludwig-Maximillians University, Munich, Germany
| | - Benjamin Strödke
- Department of Pharmacy – Center for Drug Research, Ludwig-Maximillians University, Munich, Germany
| | - Christine C. Wirth
- Institute of Molecular Biotechnology, RWTH Aachen University, Aachen, Germany
| | - Thomas Brügl
- Research Center for Infectious Diseases, University of Würzburg, Würzburg, Germany
| | | | - Thomas Dandekar
- Bioinformatics, Biocenter, University of Würzburg, Würzburg, Germany
| | - Christian Doerig
- INSERM U609, Global Health Institute, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
- Department of Microbiology, Monash University, Clayton, Victoria, Australia
| | - Rainer Fischer
- Institute of Molecular Biotechnology, RWTH Aachen University, Aachen, Germany
| | - Andrew B. Tobin
- Department of Cell Physiology and Pharmacology, MRC Toxicology Unit, University of Leicester, Leicester, United Kingdom
| | - Mahmood M. Alam
- Department of Cell Physiology and Pharmacology, MRC Toxicology Unit, University of Leicester, Leicester, United Kingdom
| | - Franz Bracher
- Department of Pharmacy – Center for Drug Research, Ludwig-Maximillians University, Munich, Germany
| | - Gabriele Pradel
- Institute of Molecular Biotechnology, RWTH Aachen University, Aachen, Germany
- * E-mail:
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30
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Rodríguez-Lombardero S, Rodríguez-Belmonte ME, González-Siso MI, Vizoso-Vázquez Á, Valdiglesias V, Laffón B, Cerdán ME. Proteomic analyses reveal that Sky1 modulates apoptosis and mitophagy in Saccharomyces cerevisiae cells exposed to cisplatin. Int J Mol Sci 2014; 15:12573-90. [PMID: 25029545 PMCID: PMC4139861 DOI: 10.3390/ijms150712573] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2014] [Revised: 07/02/2014] [Accepted: 07/02/2014] [Indexed: 12/11/2022] Open
Abstract
Sky1 is the only member of the SR (Serine–Arginine) protein kinase family in Saccharomyces cerevisiae. When yeast cells are treated with the anti-cancer drug cisplatin, Sky1 kinase activity is necessary to produce the cytotoxic effect. In this study, proteome changes in response to this drug and/or SKY1 deletion have been evaluated in order to understand the role of Sky1 in the response of yeast cells to cisplatin. Results reveal differential expression of proteins previously related to the oxidative stress response, DNA damage, apoptosis and mitophagy. With these precedents, the role of Sky1 in apoptosis, necrosis and mitophagy has been evaluated by flow-cytometry, fluorescence microscopy, biosensors and fluorescence techniques. After cisplatin treatment, an apoptotic-like process diminishes in the ∆sky1 strain in comparison to the wild-type. The treatment does not affect mitophagy in the wild-type strain, while an increase is observed in the ∆sky1 strain. The increased resistance to cisplatin observed in the ∆sky1 strain may be attributable to a decrease of apoptosis and an increase of mitophagy.
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Affiliation(s)
- Silvia Rodríguez-Lombardero
- EXPRELA Group, Department of Cellular and Molecular Biology, University of A Coruña, Campus A Coruña, A Coruña E15071, Spain.
| | - M Esther Rodríguez-Belmonte
- EXPRELA Group, Department of Cellular and Molecular Biology, University of A Coruña, Campus A Coruña, A Coruña E15071, Spain.
| | - M Isabel González-Siso
- EXPRELA Group, Department of Cellular and Molecular Biology, University of A Coruña, Campus A Coruña, A Coruña E15071, Spain.
| | - Ángel Vizoso-Vázquez
- EXPRELA Group, Department of Cellular and Molecular Biology, University of A Coruña, Campus A Coruña, A Coruña E15071, Spain.
| | - Vanessa Valdiglesias
- DICOMOSA Group, Department of Psychology, Area of Psychobiology, University of A Coruña, Campus A Coruña, A Coruña E15071, Spain.
| | - Blanca Laffón
- DICOMOSA Group, Department of Psychology, Area of Psychobiology, University of A Coruña, Campus A Coruña, A Coruña E15071, Spain.
| | - M Esperanza Cerdán
- EXPRELA Group, Department of Cellular and Molecular Biology, University of A Coruña, Campus A Coruña, A Coruña E15071, Spain.
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31
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Pease BN, Huttlin EL, Jedrychowski MP, Talevich E, Harmon J, Dillman T, Kannan N, Doerig C, Chakrabarti R, Gygi SP, Chakrabarti D. Global analysis of protein expression and phosphorylation of three stages of Plasmodium falciparum intraerythrocytic development. J Proteome Res 2013; 12:4028-45. [PMID: 23914800 DOI: 10.1021/pr400394g] [Citation(s) in RCA: 123] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
During asexual intraerythrocytic development, Plasmodium falciparum diverges from the paradigm of the eukaryotic cell cycles by undergoing multiple rounds of DNA replication and nuclear division without cytokinesis. A better understanding of the molecular switches that coordinate a myriad of events for the progression of the parasite through the intraerythrocytic developmental stages will be of fundamental importance for rational design of intervention strategies. To achieve this goal, we performed isobaric tag-based quantitative proteomics and phosphoproteomics analyses of three developmental stages in the Plasmodium asexual cycle and identified 2767 proteins, 1337 phosphoproteins, and 6293 phosphorylation sites. Approximately 34% of identified proteins and 75% of phosphorylation sites exhibit changes in abundance as the intraerythrocytic cycle progresses. Our study identified 43 distinct phosphorylation motifs and a range of potential MAPK/CDK substrates. Further analysis of phosphorylated kinases identified 30 protein kinases with 126 phosphorylation sites within the kinase domain or in N- or C-terminal tails. Many of these phosphorylations are likely CK2-mediated. We define the constitutive and regulated expression of the Plasmodium proteome during the intraerythrocytic developmental cycle, offering an insight into the dynamics of phosphorylation during asexual cycle progression. Our system-wide comprehensive analysis is a major step toward defining kinase-substrate pairs operative in various signaling networks in the parasite.
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Affiliation(s)
- Brittany N Pease
- Burnett School of Biomedical Sciences, University of Central Florida, Orlando, Florida 32826, United States
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32
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Affiliation(s)
- C A Niño
- Institut Jacques Monod, Paris Diderot University , Sorbonne Paris Cité, CNRS UMR7592, Equipe labellisée Ligue contre le cancer, 15 rue Hélène Brion, 75205 Paris Cedex 13, France
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33
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Gene expression in human fungal pathogen Coccidioides immitis changes as arthroconidia differentiate into spherules and mature. BMC Microbiol 2013; 13:121. [PMID: 23714098 PMCID: PMC3693894 DOI: 10.1186/1471-2180-13-121] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2013] [Accepted: 05/20/2013] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Coccidioides immitis is a dimorphic fungus that causes disease in mammals, including human beings. It grows as a mycelium containing arthroconidia in the soil and in the host arthroconidia differentiates into a unique structure called a spherule. We used a custom open reading frame oligonucleotide microarray to compare the transcriptome of C. immitis mycelia with early (day 2) and late stage (day 8) spherules grown in vitro. All hybridizations were done in quadruplicate and stringent criteria were used to identify significantly differentially expressed genes. RESULTS 22% of C. immitis genes were differentially expressed in either day 2 or day 8 spherules compared to mycelia, and about 12% of genes were differentially expressed comparing the two spherule time points. Oxireductases, including an extracellular superoxide dismutase, were upregulated in spherules and they may be important for defense against oxidative stress. Many signal transduction molecules, including pleckstrin domain proteins, protein kinases and transcription factors were downregulated in day 2 spherules. Several genes involved in sulfur metabolism were downregulated in day 8 spherules compared to day 2 spherules. Transcription of amylase and α (1,3) glucan synthase was upregulated in spherules; these genes have been found to be important for differentiation to yeast in Histoplasma. There were two homologs of 4-hydroxyphenylpyruvate dioxygenase (4-HPPD); transcription of one was up- and the other downregulated. We tested the effect of a 4-HPPD inhibitor, nitisinone, on mycelial and spherule growth and found that it inhibited mycelial but not spherule growth. CONCLUSIONS Transcription of many genes was differentially expressed in the process of arthroconidia to spherule conversion and spherule maturation, as would be expected given the magnitude of the morphologic change. The transcription profile of early stage (day 2) spherules was different than late stage (day 8) endosporulating spherules. In addition, very few genes that are important for spore to yeast conversion in other dimorphic fungi are differentially expressed in C. immitis mycelia and spherules suggesting that dimorphic fungi may have evolved different mechanisms to differentiate from mycelia to tissue invasive forms.
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34
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Regulation of splicing by SR proteins and SR protein-specific kinases. Chromosoma 2013; 122:191-207. [PMID: 23525660 DOI: 10.1007/s00412-013-0407-z] [Citation(s) in RCA: 312] [Impact Index Per Article: 28.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2013] [Revised: 03/04/2013] [Accepted: 03/06/2013] [Indexed: 12/21/2022]
Abstract
Genomic sequencing reveals similar but limited numbers of protein-coding genes in different genomes, which begs the question of how organismal diversities are generated. Alternative pre-mRNA splicing, a widespread phenomenon in higher eukaryotic genomes, is thought to provide a mechanism to increase the complexity of the proteome and introduce additional layers for regulating gene expression in different cell types and during development. Among a large number of factors implicated in the splicing regulation are the SR protein family of splicing factors and SR protein-specific kinases. Here, we summarize the rules for SR proteins to function as splicing regulators, which depend on where they bind in exons versus intronic regions, on alternative exons versus flanking competing exons, and on cooperative as well as competitive binding between different SR protein family members on many of those locations. We review the importance of cycles of SR protein phosphorylation/dephosphorylation in the splicing reaction with emphasis on the recent molecular insight into the role of SR protein phosphorylation in early steps of spliceosome assembly. Finally, we highlight recent discoveries of SR protein-specific kinases in transducing growth signals to regulate alternative splicing in the nucleus and the connection of both SR proteins and SR protein kinases to human diseases, particularly cancer.
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35
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Serine-arginine protein kinases: new players in neurodegenerative diseases? Rev Neurosci 2013; 24:401-13. [DOI: 10.1515/revneuro-2013-0014] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2013] [Accepted: 06/05/2013] [Indexed: 11/15/2022]
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36
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The Akt-SRPK-SR axis constitutes a major pathway in transducing EGF signaling to regulate alternative splicing in the nucleus. Mol Cell 2012; 47:422-33. [PMID: 22727668 DOI: 10.1016/j.molcel.2012.05.014] [Citation(s) in RCA: 199] [Impact Index Per Article: 16.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2012] [Revised: 04/09/2012] [Accepted: 05/10/2012] [Indexed: 11/21/2022]
Abstract
Pre-mRNA splicing is regulated by developmental and environmental cues, but little is known about how specific signals are transduced in mammalian cells to regulate this critical gene expression step. Here, we report massive reprogramming of alternative splicing in response to EGF signaling. By blocking individual branches in EGF signaling, we found that Akt activation plays a major role, while other branches, such as the JAK/STAT and ERK pathways, make minor contributions to EGF-induced splicing. Activated Akt next branches to SR protein-specific kinases, rather than mTOR, by inducing SRPK autophosphorylation that switches the splicing kinases from Hsp70- to Hsp90-containing complexes. This leads to enhanced SRPK nuclear translocation and SR protein phosphorylation. These findings reveal a major signal transduction pathway for regulated splicing and place SRPKs in a central position in the pathway, consistent with their reputed roles in a large number of human cancers.
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37
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Kim YC, Kim BG, Lee JH. Thymosin β10 expression driven by the human TERT promoter induces ovarian cancer-specific apoptosis through ROS production. PLoS One 2012; 7:e35399. [PMID: 22623951 PMCID: PMC3356296 DOI: 10.1371/journal.pone.0035399] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2011] [Accepted: 03/16/2012] [Indexed: 11/18/2022] Open
Abstract
Thymosin β(10) (Tβ(10)) regulates actin dynamics as a cytoplasm G-actin sequestering protein. Previously, we have shown that Tβ(10) diminishes tumor growth, angiogenesis, and proliferation by disrupting actin and by inhibiting Ras. However, little is known about its mechanism of action and biological function. In the present study, we establish a new gene therapy model using a genetically modified adenovirus, referred to as Ad.TERT.Tβ(10), that can overexpress the Tβ(10) gene in cancer cells. This was accomplished by replacing the native Tβ(10) gene promoter with the human TERT promoter in Ad.TERT.Tβ(10). We investigated the cancer suppression activity of Tβ(10) and found that Ad.TERT.Tβ(10) strikingly induced cancer-specific expression of Tβ(10) as well as apoptosis in a co-culture model of human primary ovarian cancer cells and normal fibroblasts. Additionally, Ad.TERT.Tβ(10) decreased mitochondrial membrane potential and increased reactive oxygen species (ROS) production. These effects were amplified by co-treatment with anticancer drugs, such as paclitaxel and cisplatin. These findings indicate that the rise in ROS production due to actin disruption by Tβ(10) overexpression increases apoptosis of human ovarian cancer cells. Indeed, the cancer-specific overexpression of Tβ(10) by Ad.TERT.Tβ(10) could be a valuable anti-cancer therapeutic for the treatment of ovarian cancer without toxicity to normal cells.
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Affiliation(s)
- Young-Chae Kim
- Department of Obstetrics and Gynecology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Gangnam-gu, Seoul, Korea
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Torabi N, Kruglyak L. Genetic basis of hidden phenotypic variation revealed by increased translational readthrough in yeast. PLoS Genet 2012; 8:e1002546. [PMID: 22396662 PMCID: PMC3291563 DOI: 10.1371/journal.pgen.1002546] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2011] [Accepted: 12/28/2011] [Indexed: 01/07/2023] Open
Abstract
Eukaryotic release factors 1 and 3, encoded by SUP45 and SUP35, respectively, in Saccharomyces cerevisiae, are required for translation termination. Recent studies have shown that, besides these two key factors, several genetic and epigenetic mechanisms modulate the efficiency of translation termination. These mechanisms, through modifying translation termination fidelity, were shown to affect various cellular processes, such as mRNA degradation, and in some cases could confer a beneficial phenotype to the cell. The most studied example of such a mechanism is [PSI+], the prion conformation of Sup35p, which can have pleiotropic effects on growth that vary among different yeast strains. However, genetic loci underlying such readthrough-dependent, background-specific phenotypes have yet to be identified. Here, we used sup35C653R, a partial loss-of-function allele of the SUP35 previously shown to increase readthrough of stop codons and recapitulate some [PSI+]-dependent phenotypes, to study the genetic basis of phenotypes revealed by increased translational readthrough in two divergent yeast strains: BY4724 (a laboratory strain) and RM11_1a (a wine strain). We first identified growth conditions in which increased readthrough of stop codons by sup35C653R resulted in different growth responses between these two strains. We then used a recently developed linkage mapping technique, extreme QTL mapping (X-QTL), to identify readthrough-dependent loci for the observed growth differences. We further showed that variation in SKY1, an SR protein kinase, underlies a readthrough-dependent locus observed for growth on diamide and hydrogen peroxide. We found that the allelic state of SKY1 interacts with readthrough level and the genetic background to determine growth rate in these two conditions. Proper termination is an important step in a successful mRNA translation event. Many factors, employing genetic and epigenetic mechanisms, are involved in modifying translation termination efficiency in the budding yeast, Saccharomyces cerevisiae. [PSI+], the prion conformation of Sup35p, one of the translation termination factors in yeast, provides an example of such mechanisms. [PSI+] increases readthrough of stop codons. This has the potential to unveil hidden genetic variation that may enhance growth in some yeast strains in certain environments. The specific details of readthrough-dependent phenotypes, however, have remained poorly understood. Here, we used a partial loss-of-function allele of SUP35, which increases readthrough of stop codons, and a recently developed linkage mapping technique, X-QTL, to map loci underlying readthrough-dependent growth phenotypes in two divergent yeast strains, BY (a laboratory strain) and RM (a wine strain). We found that readthrough-dependent growth phenotypes are often complex, with multiple loci influencing growth. We also showed that variants in the gene SKY1 underlie one of the loci detected for readthrough-dependent growth phenotypes in the presence of two chemicals that induce oxidative stress.
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Affiliation(s)
- Noorossadat Torabi
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, New Jersey, United States of America
- Department of Molecular Biology, Princeton University, Princeton, New Jersey, United States of America
| | - Leonid Kruglyak
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, New Jersey, United States of America
- Department of Ecology and Evolutionary Biology, Princeton University, Princeton, New Jersey, United States of America
- Howard Hughes Medical Institute, Princeton University, Princeton, New Jersey, United States of America
- * E-mail:
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Chen C, Wang JCY, Zlotnick A. A kinase chaperones hepatitis B virus capsid assembly and captures capsid dynamics in vitro. PLoS Pathog 2011; 7:e1002388. [PMID: 22114561 PMCID: PMC3219723 DOI: 10.1371/journal.ppat.1002388] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2011] [Accepted: 10/04/2011] [Indexed: 12/14/2022] Open
Abstract
The C-terminal domain (CTD) of Hepatitis B virus (HBV) core protein is involved in regulating multiple stages of the HBV lifecycle. CTD phosphorylation correlates with pregenomic-RNA encapsidation during capsid assembly, reverse transcription, and viral transport, although the mechanisms remain unknown. In vitro, purified HBV core protein (Cp183) binds any RNA and assembles aggressively, independent of phosphorylation, to form empty and RNA-filled capsids. We hypothesize that there must be a chaperone that binds the CTD to prevent self-assembly and nonspecific RNA packaging. Here, we show that HBV capsid assembly is stalled by the Serine Arginine protein kinase (SRPK) binding to the CTD, and reactivated by subsequent phosphorylation. Using the SRPK to probe capsids, solution and structural studies showed that SRPK bound to capsid, though the CTD is sequestered on the capsid interior. This result indicates transient CTD externalization and suggests that capsid dynamics could be crucial for directing HBV intracellular trafficking. Our studies illustrate the stochastic nature of virus capsids and demonstrate the appropriation of a host protein by a virus for a non-canonical function. A virus particle is a molecular machine that has evolved to self-assemble within the confines of a living cell. For hepatitis B virus (HBV), outside of a cell, the self-assembly process is very aggressive and consequently not specific for viral RNA. Here we show that HBV takes advantage of a host protein, SRPK, which acts like a molecular chaperone, to prevent the HBV core protein from binding RNA and to prevent the core protein from assembling at the wrong time and place. At the right time, SRPK can be removed in a regulated reaction to allow assembly. Once a virus is assembled, it must traffic to the right intracellular locale. Using SRPK, we show that HBV cores can transiently expose a segment of protein, normally inside the virus, that carries a signal for transport to the host nucleus. This is the first example we know of where a virus repurposes an enzyme for an alternative function. This sort of interplay between virus and host, where the virus hijacks and repurposes host proteins, is likely to be a common feature of viral infection.
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Affiliation(s)
- Chao Chen
- Department of Molecular and Cellular Biochemistry, Indiana University, Bloomington, Indiana, United States of America
| | - Joseph Che-Yen Wang
- Department of Molecular and Cellular Biochemistry, Indiana University, Bloomington, Indiana, United States of America
| | - Adam Zlotnick
- Department of Molecular and Cellular Biochemistry, Indiana University, Bloomington, Indiana, United States of America
- * E-mail:
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Agarwal S, Kern S, Halbert J, Przyborski JM, Baumeister S, Dandekar T, Doerig C, Pradel G. Two nucleus-localized CDK-like kinases with crucial roles for malaria parasite erythrocytic replication are involved in phosphorylation of splicing factor. J Cell Biochem 2011; 112:1295-310. [PMID: 21312235 DOI: 10.1002/jcb.23034] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The kinome of the human malaria parasite Plasmodium falciparum comprises representatives of most eukaryotic protein kinase groups, including kinases which regulate proliferation and differentiation processes. Despite extensive research on most plasmodial enzymes, little information is available regarding the four identified members of the cyclin-dependent kinase-like kinase (CLK) family. In other eukaryotes, CLKs regulate mRNA splicing through phosphorylation of Serine/Arginine-rich proteins. Here, we investigate two of the PfCLKs, the Lammer kinase homolog PfCLK-1, and PfCLK-2. Both PfCLKs show homology with the yeast Serine/Arginine protein kinase Sky1p and are transcribed throughout the asexual blood stages and in gametocytes. PfCLK-1/Lammer possesses two nuclear localization signal sites and PfCLK-2 possesses one of these signal sites upstream of the C-terminal catalytic domains. Indirect immunofluorescence, Western blot, and electron microscopy data confirm that the kinases are primarily localized in the parasite nucleus, and PfCLK-2 is further present in the cytoplasm. The two kinases are important for completion of the asexual replication cycle of P. falciparum, as demonstrated by reverse genetics approaches. In vitro kinase assays show substrate phosphorylation by the PfCLKs, including the Sky1p substrate, splicing factor Npl3p, and the plasmodial alternative splicing factor PfASF-1. Mass spectrometric analysis of co-immunoprecipitated proteins indicates assembly of the two PfCLKs with proteins with predicted nuclease, phosphatase, or helicase functions. Our data indicate a crucial role of PfCLKs for malaria blood stage parasites, presumably by participating in gene regulation through the post-transcriptional modification of mRNA.
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Affiliation(s)
- Shruti Agarwal
- Research Center for Infectious Diseases, University of Würzburg, Josef-Schneider-Strasse 2, Building D15, 97080 Würzburg, Germany
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LAMMER kinase Kic1 is involved in pre-mRNA processing. Exp Cell Res 2011; 317:2308-20. [PMID: 21745468 DOI: 10.1016/j.yexcr.2011.06.014] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2011] [Revised: 06/22/2011] [Accepted: 06/23/2011] [Indexed: 01/03/2023]
Abstract
The LAMMER kinases are conserved through evolution. They play vital roles in cell growth/differentiation, development, and metabolism. One of the best known functions of the kinases in animal cells is the regulation of pre-mRNA splicing. Kic1 is the LAMMER kinase in fission yeast Schizosaccharomyces pombe. Despite the reported pleiotropic effects of kic1+ deletion/overexpression on various cellular processes the involvement of Kic1 in splicing remains elusive. In this study, we demonstrate for the first time that Kic1 not only is required for efficient splicing but also affects mRNA export, providing evidence for the conserved roles of LAMMER kinases in the unicellular context of fission yeast. Consistent with the hypothesis of its direct participation in multiple steps of pre-mRNA processing, Kic1 is predominantly present in the nucleus during interphase. In addition, the kinase activity of Kic1 plays a role in modulating its own cellular partitioning. Interestingly, Kic1 expression oscillates in a cell cycle-dependent manner and the peak level coincides with mitosis and cytokinesis, revealing a potential mechanism for controlling the kinase activity during the cell cycle. The novel information about the in vivo functions and regulation of Kic1 offers insights into the conserved biological roles fundamental to LAMMER kinases in eukaryotes.
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Giannakouros T, Nikolakaki E, Mylonis I, Georgatsou E. Serine-arginine protein kinases: a small protein kinase family with a large cellular presence. FEBS J 2011; 278:570-86. [DOI: 10.1111/j.1742-4658.2010.07987.x] [Citation(s) in RCA: 99] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
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Dixit A, Singh PK, Sharma GP, Malhotra P, Sharma P. PfSRPK1, a novel splicing-related kinase from Plasmodium falciparum. J Biol Chem 2010; 285:38315-23. [PMID: 20870716 DOI: 10.1074/jbc.m110.119255] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Even though it is increasingly evident that post-transcriptional events like mRNA processing and splicing may regulate gene expression and proteome diversity of malaria parasite Plasmodium, molecular mechanisms that regulate events like mRNA splicing in malaria parasite are poorly understood. Protein kinases control a wide variety of cellular events in almost all eukaryotes, including modulation of mRNA splicing, transport, and stability. We have identified a novel splicing-related protein kinase from Plasmodium falciparum, PfSRPK1. PfSRPK1 when incubated with parasite nuclear extracts inhibited RNA splicing, suggesting that it may control mRNA splicing in the parasite. PfSR1, a putative splicing factor from P. falciparum, was identified as a substrate of PfSRPK1. PfSR1 interacts with RNA and PfSRPK1 modulates its RNA binding. Early in the parasite development, PfSRPK1 and PfSR1 are present in the nucleus. These studies provide useful insights into the function of two potentially key components of P. falciparum mRNA splicing machinery.
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Affiliation(s)
- Aparna Dixit
- Eukaryotic Gene Expression Laboratory, National Institute of Immunology, New Delhi 110067, India
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Nuclear export of mRNA. Trends Biochem Sci 2010; 35:609-17. [PMID: 20719516 DOI: 10.1016/j.tibs.2010.07.001] [Citation(s) in RCA: 100] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2010] [Revised: 07/05/2010] [Accepted: 07/07/2010] [Indexed: 01/19/2023]
Abstract
The nuclear export of mRNA, in which Mex67-Mtr2 mediates movement of mature transcripts through nuclear pores, represents the culmination of the nuclear portion of the gene expression pathway. Nuclear export is closely integrated with transcription and processing, and is based on forming a messenger ribonucleoprotein (mRNP) export complex in the nucleus that is able to diffuse back and forth through the pores. Directionality is imposed by remodelling of the mRNP in the cytoplasm, thereby removing key transport-related proteins and preventing its return to the nucleus. The nuclear and cytoplasmic steps of this pathway, in which Mex67-Mtr2 and Nab2 are added and removed, are crucial, and both involve remodelling of the mRNP, which is mediated by DEAD-box helicases together with adaptor and accessory proteins. Recent structural and cell biology results provide key information that should enable development of a detailed understanding of this central cellular process at a molecular level.
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Wong CM, Tang HMV, Kong KYE, Wong GWO, Qiu H, Jin DY, Hinnebusch AG. Yeast arginine methyltransferase Hmt1p regulates transcription elongation and termination by methylating Npl3p. Nucleic Acids Res 2010; 38:2217-28. [PMID: 20053728 PMCID: PMC2853106 DOI: 10.1093/nar/gkp1133] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The heterogeneous nuclear ribonucleoprotein Npl3p of budding yeast is a substrate of arginine methyltransferase Hmt1p, but the role of Hmt1p in regulating Npl3p's functions in transcription antitermination and elongation were unknown. We found that mutants lacking Hmt1p methyltransferase activity exhibit reduced recruitment of Npl3p, but elevated recruitment of a component of mRNA cleavage/termination factor CFI, to the activated GAL10-GAL7 locus. Consistent with this, hmt1 mutants displayed increased termination at the defective gal10-Delta56 terminator. Remarkably, hmt1Delta cells also exhibit diminished recruitment of elongation factor Tho2p and a reduced rate of transcription elongation in vivo. Importantly, the defects in Npl3p and Tho2p recruitment, antitermination and elongation in hmt1Delta cells all were mitigated by substitutions in Npl3p RGG repeats that functionally mimic arginine methylation by Hmt1p. Thus, Hmt1p promotes elongation and suppresses termination at cryptic terminators by methylating RGG repeats in Npl3p. As Hmt1p stimulates dissociation of Tho2p from an Npl3p-mRNP complex, it could act to recycle these elongation and antitermination factors back to sites of ongoing transcription.
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Affiliation(s)
- Chi-Ming Wong
- Department of Biochemistry, The University of Hong Kong, Hong Kong.
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Nieratschker V, Schubert A, Jauch M, Bock N, Bucher D, Dippacher S, Krohne G, Asan E, Buchner S, Buchner E. Bruchpilot in ribbon-like axonal agglomerates, behavioral defects, and early death in SRPK79D kinase mutants of Drosophila. PLoS Genet 2009; 5:e1000700. [PMID: 19851455 PMCID: PMC2759580 DOI: 10.1371/journal.pgen.1000700] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2009] [Accepted: 09/23/2009] [Indexed: 12/18/2022] Open
Abstract
Defining the molecular structure and function of synapses is a central theme in brain research. In Drosophila the Bruchpilot (BRP) protein is associated with T-shaped ribbons ("T-bars") at presynaptic active zones (AZs). BRP is required for intact AZ structure and normal evoked neurotransmitter release. By screening for mutations that affect the tissue distribution of Bruchpilot, we have identified a P-transposon insertion in gene CG11489 (location 79D) which shows high homology to mammalian genes for SR protein kinases (SRPKs). SRPKs phosphorylate serine-arginine rich splicing factors (SR proteins). Since proteins expressed from CG11489 cDNAs phosphorylate a peptide from a human SR protein in vitro, we name CG11489 the Drosophila Srpk79D gene. We have characterized Srpk79D transcripts and generated a null mutant. Mutation of the Srpk79D gene causes conspicuous accumulations of BRP in larval and adult nerves. At the ultrastructural level, these correspond to extensive axonal agglomerates of electron-dense ribbons surrounded by clear vesicles. Basic synaptic structure and function at larval neuromuscular junctions appears normal, whereas life expectancy and locomotor behavior of adult mutants are significantly impaired. All phenotypes of the mutant can be largely or completely rescued by panneural expression of SRPK79D isoforms. Isoform-specific antibodies recognize panneurally overexpressed GFP-tagged SRPK79D-PC isoform co-localized with BRP at presynaptic active zones while the tagged -PB isoform is found in spots within neuronal perikarya. SRPK79D concentrations in wild type apparently are too low to be revealed by these antisera. We propose that the Drosophila Srpk79D gene characterized here may be expressed at low levels throughout the nervous system to prevent the assembly of BRP containing agglomerates in axons and maintain intact brain function. The discovery of an SR protein kinase required for normal BRP distribution calls for the identification of its substrate and the detailed analysis of SRPK function for the maintenance of nervous system integrity.
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Affiliation(s)
- Vanessa Nieratschker
- Department of Genetics and Neurobiology, Julius-Maximilians-University, Würzburg, Germany
| | - Alice Schubert
- Department of Genetics and Neurobiology, Julius-Maximilians-University, Würzburg, Germany
| | - Mandy Jauch
- Department of Genetics and Neurobiology, Julius-Maximilians-University, Würzburg, Germany
| | - Nicole Bock
- Department of Genetics and Neurobiology, Julius-Maximilians-University, Würzburg, Germany
| | - Daniel Bucher
- Department of Genetics and Neurobiology, Julius-Maximilians-University, Würzburg, Germany
| | - Sonja Dippacher
- Department of Genetics and Neurobiology, Julius-Maximilians-University, Würzburg, Germany
- Institute of Anatomy and Cell Biology, Julius-Maximilians-University, Würzburg, Germany
| | - Georg Krohne
- Department of Electron Microscopy, Julius-Maximilians-University, Würzburg, Germany
| | - Esther Asan
- Institute of Anatomy and Cell Biology, Julius-Maximilians-University, Würzburg, Germany
| | - Sigrid Buchner
- Department of Genetics and Neurobiology, Julius-Maximilians-University, Würzburg, Germany
| | - Erich Buchner
- Department of Genetics and Neurobiology, Julius-Maximilians-University, Würzburg, Germany
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Liu S, Zhou Z, Lin Z, Ouyang Q, Zhang J, Tian S, Xing M. Identification of a nuclear localization motif in the serine/arginine protein kinase PSRPK of physarum polycephalum. BMC BIOCHEMISTRY 2009; 10:22. [PMID: 19703313 PMCID: PMC2754491 DOI: 10.1186/1471-2091-10-22] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/28/2009] [Accepted: 08/25/2009] [Indexed: 11/13/2022]
Abstract
Background Serine/arginine (SR) protein-specific kinases (SRPKs) are conserved in a wide range of organisms, from humans to yeast. Studies showed that SRPKs can regulate the nuclear import of SR proteins in cytoplasm, and regulate the sub-localization of SR proteins in the nucleus. But no nuclear localization signal (NLS) of SRPKs was found. We isolated an SRPK-like protein PSRPK (GenBank accession No. DQ140379) from Physarum polycephalum previously, and identified a NLS of PSRPK in this study. Results We carried out a thorough molecular dissection of the different domains of the PSRPK protein involved in its nuclear localization. By truncation of PSRPK protein, deletion of and single amino acid substitution in a putative NLS and transfection of mammalian cells, we observed the distribution of PSRPK fluorescent fusion protein in mammalian cells using confocal microscopy and found that the protein was mainly accumulated in the nucleus; this indicated that the motif contained a nuclear localization signal (NLS). Further investigation with truncated PSPRK peptides showed that the NLS (318PKKGDKYDKTD328) was localized in the alkaline Ω-loop of a helix-loop-helix motif (HLHM) of the C-terminal conserved domain. If the 318PKKGDK322 sequence was deleted from the loop or K320 was mutated to T320, the PSRPK fluorescent fusion protein could not enter and accumulate in the nucleus. Conclusion This study demonstrated that the 318PKKGDKYDKTD328 peptides localized in the C-terminal conserved domain of PSRPK with the Ω-loop structure could play a crucial role in the NLS function of PSRPK.
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Affiliation(s)
- Shide Liu
- Shenzhen Key Laboratory of Microbial Genetic Engineering and College of Life Science, Shenzhen University, Shenzhen, PR China.
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Huber A, Bodenmiller B, Uotila A, Stahl M, Wanka S, Gerrits B, Aebersold R, Loewith R. Characterization of the rapamycin-sensitive phosphoproteome reveals that Sch9 is a central coordinator of protein synthesis. Genes Dev 2009; 23:1929-43. [PMID: 19684113 PMCID: PMC2725941 DOI: 10.1101/gad.532109] [Citation(s) in RCA: 261] [Impact Index Per Article: 17.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2009] [Accepted: 06/19/2009] [Indexed: 12/12/2022]
Abstract
The target of rapamycin complex 1 (TORC1) is an essential multiprotein complex conserved from yeast to humans. Under favorable growth conditions, and in the absence of the macrolide rapamycin, TORC1 is active, and influences virtually all aspects of cell growth. Although two direct effectors of yeast TORC1 have been reported (Tap42, a regulator of PP2A phosphatases and Sch9, an AGC family kinase), the signaling pathways that couple TORC1 to its distal effectors were not well understood. To elucidate these pathways we developed and employed a quantitative, label-free mass spectrometry approach. Analyses of the rapamycin-sensitive phosphoproteomes in various genetic backgrounds revealed both documented and novel TORC1 effectors and allowed us to partition phosphorylation events between Tap42 and Sch9. Follow-up detailed characterization shows that Sch9 regulates RNA polymerases I and III, the latter via Maf1, in addition to translation initiation and the expression of ribosomal protein and ribosome biogenesis genes. This demonstrates that Sch9 is a master regulator of protein synthesis.
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Affiliation(s)
- Alexandre Huber
- Department of Molecular Biology, University of Geneva, Geneva 1211, Switzerland
| | - Bernd Bodenmiller
- Institute of Molecular Systems Biology, ETH Zürich, Zürich 8093, Switzerland
| | - Aino Uotila
- Department of Molecular Biology, University of Geneva, Geneva 1211, Switzerland
| | - Michael Stahl
- Department of Molecular Biology, University of Geneva, Geneva 1211, Switzerland
| | - Stefanie Wanka
- Institute of Molecular Biology, University of Zurich, Zürich 8057, Switzerland
| | - Bertran Gerrits
- Functional Genomics Center Zurich, University of Zürich, Zürich 8057, Switzerland
| | - Ruedi Aebersold
- Institute of Molecular Systems Biology, ETH Zürich, Zürich 8093, Switzerland
- Institute for Systems Biology, Seattle, Washington 98103, USA
- Competence Center for Systems Physiology and Metabolic Diseases, ETH Zürich, Zürich 8093, Switzerland
- Faculty of Science, University of Zürich, Zürich 8057, Switzerland
| | - Robbie Loewith
- Department of Molecular Biology, University of Geneva, Geneva 1211, Switzerland
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Tsianou D, Nikolakaki E, Tzitzira A, Bonanou S, Giannakouros T, Georgatsou E. The enzymatic activity of SR protein kinases 1 and 1a is negatively affected by interaction with scaffold attachment factors B1 and 2. FEBS J 2009; 276:5212-27. [PMID: 19674106 DOI: 10.1111/j.1742-4658.2009.07217.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
SR protein kinases (SRPKs) phosphorylate Ser/Arg dipeptide-containing proteins that play crucial roles in a broad spectrum of basic cellular processes. Phosphorylation by SRPKs constitutes a major way of regulating such cellular mechanisms. In the past, we have shown that SRPK1a interacts with the nuclear matrix protein scaffold attachment factor B1 (SAFB1) via its unique N-terminal domain, which differentiates it from SRPK1. In this study, we show that SAFB1 inhibits the activity of both SRPK1a and SRPK1 in vitro and that its RE-rich region is redundant for the observed inhibition. We demonstrate that kinase activity inhibition is caused by direct binding of SAFB1 to SRPK1a and SRPK1, and we also present evidence for the in vitro binding of SAFB2 to the two kinases, albeit with different affinity. Moreover, we show that both SR protein kinases can form complexes with both scaffold attachment factors B in living cells and that this interaction is capable of inhibiting their activity, depending on the tenacity of the complex formed. Finally, we present data demonstrating that SRPK/SAFB complexes are present in the nucleus of HeLa cells and that the enzymatic activity of the nuclear matrixlocalized SRPK1 is repressed. These results suggest a new role for SAFB proteins as regulators of SRPK activity and underline the importance of the assembly of transient intranuclear complexes in cellular regulation.
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Affiliation(s)
- Dora Tsianou
- Department of Medicine, University of Thessaly, Mezourlo, 41110 Larissa, Greece
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50
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Liu S, Kang K, Zhang J, Ouyang Q, Zhou Z, Tian S, Xing M. A novel Physarum polycephalum SR protein kinase specifically phosphorylates the RS domain of the human SR protein, ASF/SF2. Acta Biochim Biophys Sin (Shanghai) 2009; 41:657-67. [PMID: 19657567 DOI: 10.1093/abbs/gmp054] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
A 1591-bp cDNA of a serine-rich protein kinase (SRPK)-like protein has been identified in Physarum polycephalum (GenBank accession No. DQ140379). The cDNA contains two repeat sequences at bp 1-153 and bp 395-547. The encoding sequence is 56% homologous to human SRPK1 and is named Physarum SRPK (PSRPK). Consistent with other SRPKs, the consensus motifs of PSRPK are within the two conserved domains (CDs). However, divergent motifs between the N-terminal and CDs are much shorter than the corresponding sequences of other SRPKs. To study the structure and function of this protein, we performed co-expression experiment in Escherichia coli and in vitro phosphorylation assay to investigate the phosphorylation effect of recombinant PSRPK on the human SR protein, ASF/SF2. Western blot analysis showed that PSRPK could phosphorylate ASF/SF2 in E. coli cells. Autoradiographic examination showed that both recombinant PSRPK and a truncated form of PSRPK with a 28-aa deletion at the N-terminus could phosphorylate ASF/SF2 and a truncated form of ASF/SF2 that contains the RS domain. However, these two forms of PSRPK could not phosphorylate a truncated form ASF/SF2 that lacks the RS domain. A truncated form of PSRPK that lacks either of CDs does not have any phosphorylation activity. These results indicated that, like other SRPKs, the phosphorylation site in PSRPK is located within the RS domain of the SR protein and that its phosphorylation activity is closely associated with the two CDs. This study on the structure and function of PSRPK demonstrates that it is a new member of the SRPK family.
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Affiliation(s)
- Shide Liu
- Shenzhen Key Laboratory of Microbial and Genetic Engineering, College of Life Science Shenzhen University, Shenzhen, China
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