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Ghosh Dastidar R, Banerjee S, Lal PB, Ghosh Dastidar S. Multifaceted Roles of AFG3L2, a Mitochondrial ATPase in Relation to Neurological Disorders. Mol Neurobiol 2023:10.1007/s12035-023-03768-z. [PMID: 38012514 DOI: 10.1007/s12035-023-03768-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2023] [Accepted: 11/01/2023] [Indexed: 11/29/2023]
Abstract
AFG3L2 is a zinc metalloprotease and an ATPase localized in an inner mitochondrial membrane involved in mitochondrial quality control of several nuclear- and mitochondrial-encoded proteins. Mutations in AFG3L2 lead to diseases like slow progressive ataxia, which is a neurological disorder. This review delineates the cellular functions of AFG3L2 and its dysfunction that leads to major clinical outcomes, which include spinocerebellar ataxia type 28, spastic ataxia type 5, and optic atrophy type 12. It summarizes all relevant AFG3L2 mutations associated with the clinical outcomes to understand the detailed mechanisms attributable to its structure-related multifaceted roles in proteostasis and quality control. We face early diagnostic challenges of ataxia and optic neuropathy due to asymptomatic parents and variable clinical manifestations due to heterozygosity/homozygosity of AFG3L2 mutations. This review intends to promote AFG3L2 as a putative prognostic or diagnostic marker. Functions, mutations, and clinical manifestations in AFG3L2, a mitochondrial AAA + ATPases.
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Affiliation(s)
- Ranita Ghosh Dastidar
- Department of Biochemistry, Kasturba Medical College, Manipal, Manipal Academy of Higher Education, Manipal, Madhava Nagar, Manipal, 576104, Karnataka, India.
| | - Saradindu Banerjee
- Centre for Molecular Neurosciences, Kasturba Medical College, Manipal, Manipal Academy of Higher Education, Manipal, Madhava Nagar, Manipal, 576104, Karnataka, India
| | - Piyush Behari Lal
- Department of Microbiology, Kasturba Medical College, Manipal, Manipal Academy of Higher Education, Manipal, Madhava Nagar, Manipal, 576104, Karnataka, India.
| | - Somasish Ghosh Dastidar
- Centre for Molecular Neurosciences, Kasturba Medical College, Manipal, Manipal Academy of Higher Education, Manipal, Madhava Nagar, Manipal, 576104, Karnataka, India.
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Tsirkas I, Zur T, Dovrat D, Cohen A, Ravkaie L, Aharoni A. Protein fluorescent labeling in live yeast cells using scFv-based probes. CELL REPORTS METHODS 2022; 2:100357. [PMID: 36590693 PMCID: PMC9795370 DOI: 10.1016/j.crmeth.2022.100357] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/26/2022] [Revised: 09/19/2022] [Accepted: 11/10/2022] [Indexed: 12/12/2022]
Abstract
The fusion of fluorescent proteins (FPs) to endogenous proteins is a widespread approach for microscopic examination of protein function, expression, and localization in the cell. However, proteins that are sensitive to FP fusion or expressed at low levels are difficult to monitor using this approach. Here, we develop a single-chain fragment variable (scFv)-FP approach to efficiently label Saccharomyces cerevisiae proteins that are tagged with repeats of hemagglutinin (HA)-tag sequences. We demonstrate the successful labeling of DNA-binding proteins and proteins localized to different cellular organelles including the nuclear membrane, peroxisome, Golgi apparatus, and mitochondria. This approach can lead to a significant increase in fluorescence intensity of the labeled protein, allows C'-terminal labeling of difficult-to-tag proteins and increased detection sensitivity of DNA-damage foci. Overall, the development of a scFv-FP labeling approach in yeast provides a general and simple tool for the function and localization analysis of the yeast proteome.
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Affiliation(s)
- Ioannis Tsirkas
- Department of Life Sciences and the National Institute for Biotechnology in the Negev, Ben-Gurion University of the Negev, Be’er Sheva 84105, Israel
| | - Tomer Zur
- Department of Life Sciences and the National Institute for Biotechnology in the Negev, Ben-Gurion University of the Negev, Be’er Sheva 84105, Israel
| | - Daniel Dovrat
- Department of Life Sciences and the National Institute for Biotechnology in the Negev, Ben-Gurion University of the Negev, Be’er Sheva 84105, Israel
| | - Amit Cohen
- Department of Life Sciences and the National Institute for Biotechnology in the Negev, Ben-Gurion University of the Negev, Be’er Sheva 84105, Israel
| | - Lior Ravkaie
- Department of Life Sciences and the National Institute for Biotechnology in the Negev, Ben-Gurion University of the Negev, Be’er Sheva 84105, Israel
| | - Amir Aharoni
- Department of Life Sciences and the National Institute for Biotechnology in the Negev, Ben-Gurion University of the Negev, Be’er Sheva 84105, Israel
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Hypoxia Selectively Increases a SMAD3 Signaling Axis to Promote Cancer Cell Invasion. Cancers (Basel) 2022; 14:cancers14112751. [PMID: 35681731 PMCID: PMC9179584 DOI: 10.3390/cancers14112751] [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: 05/18/2022] [Accepted: 05/30/2022] [Indexed: 01/27/2023] Open
Abstract
Transforming growth factor β (TGFβ) plays a paradoxical role in cancer, first inhibiting then promoting its progression, a duality that poses a real challenge for the development of effective TGFβ-targeted therapies. The major TGFβ downstream effectors, SMAD2 and SMAD3, display both distinct and overlapping functions and accumulating evidence suggests that their activation ratio may contribute to the dual effect of TGFβ. However, the mechanisms responsible for their selective activation remain poorly understood. Here, we provide experimental evidence that hypoxia induces the pro-invasive arm of TGFβ signaling through a selective increase in SMAD3 interaction with SMAD-Anchor for Receptor Activation (SARA). This event relies on HDAC6-dependent SMAD3 bioavailability, as well as increased SARA recruitment to EEA1+ endosomes. A motility gene expression study indicated that SMAD3 selectively increased the expression of ITGB2 and VIM, two genes that were found to be implicated in hypoxia-induced cell invasion and associated with tumor progression and metastasis in cohorts of cancer patients. Furthermore, CAM xenograft assays show the significant benefit of selective inhibition of the SMAD3 signaling pathway as opposed to global TGFβ inhibition in preventing tumor progression. Overall, these results suggest that fine-tuning of the pro-invasive HDAC6-SARA-SMAD3 axis could be a better strategy towards effective cancer treatments.
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Non-histone protein acetylation by the evolutionarily conserved GCN5 and PCAF acetyltransferases. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2020; 1864:194608. [PMID: 32711095 DOI: 10.1016/j.bbagrm.2020.194608] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 04/11/2020] [Revised: 07/13/2020] [Accepted: 07/15/2020] [Indexed: 01/08/2023]
Abstract
GCN5, conserved from yeast to humans, and the vertebrate specific PCAF, are lysine acetyltransferase enzymes found in large protein complexes. Both enzymes have well documented roles in the histone acetylation and the concomitant regulation of transcription. However, these enzymes also acetylate non-histone substrates to impact diverse aspects of cell physiology. Here, I review our current understanding of non-histone acetylation by GCN5 and PCAF across eukaryotes, from target identification to molecular mechanism and regulation. I focus mainly on budding yeast, where Gcn5 was first discovered, and mammalian systems, where the bulk of non-histone substrates have been characterized. I end the review by defining critical caveats and open questions that apply to all models.
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Lal S, Comer JM, Konduri PC, Shah A, Wang T, Lewis A, Shoffner G, Guo F, Zhang L. Heme promotes transcriptional and demethylase activities of Gis1, a member of the histone demethylase JMJD2/KDM4 family. Nucleic Acids Res 2019; 46:215-228. [PMID: 29126261 PMCID: PMC5758875 DOI: 10.1093/nar/gkx1051] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2016] [Accepted: 10/19/2017] [Indexed: 12/17/2022] Open
Abstract
The yeast Gis1 protein is a transcriptional regulator belonging to the JMJD2/KDM4 subfamily of demethylases that contain a JmjC domain, which are highly conserved from yeast to humans. They have important functions in histone methylation, cellular signaling and tumorigenesis. Besides serving as a cofactor in many proteins, heme is known to directly regulate the activities of proteins ranging from transcriptional regulators to potassium channels. Here, we report a novel mechanism governing heme regulation of Gis1 transcriptional and histone demethylase activities. We found that two Gis1 modules, the JmjN + JmjC domain and the zinc finger (ZnF), can bind to heme specifically in vitro. In vivo functional analysis showed that the ZnF, not the JmjN + JmjC domain, promotes heme activation of transcriptional activity. Likewise, measurements of the demethylase activity of purified Gis1 proteins showed that full-length Gis1 and the JmjN + JmjC domain both possess demethylase activity. However, heme potentiates the demethylase activity of full-length Gis1, but not that of the JmjN + JmjC domain, which can confer heme activation of transcriptional activity in an unrelated protein. These results demonstrate that Gis1 represents a novel class of multi-functional heme sensing and signaling proteins, and that heme binding to the ZnF stimulates Gis1 demethylase and transcriptional activities.
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Affiliation(s)
- Sneha Lal
- Department of Biological Sciences, University of Texas at Dallas, Mail Stop RL11, 800 W. Campbell Road, Richardson, TX 75080, USA
| | - Jonathan M Comer
- Department of Biological Sciences, University of Texas at Dallas, Mail Stop RL11, 800 W. Campbell Road, Richardson, TX 75080, USA
| | - Purna C Konduri
- Department of Biological Sciences, University of Texas at Dallas, Mail Stop RL11, 800 W. Campbell Road, Richardson, TX 75080, USA
| | - Ajit Shah
- Diabetes Center, University of California San Francisco, San Francisco, CA 94143, USA
| | - Tianyuan Wang
- Department of Biological Sciences, University of Texas at Dallas, Mail Stop RL11, 800 W. Campbell Road, Richardson, TX 75080, USA
| | - Anthony Lewis
- Department of Biological Sciences, University of Texas at Dallas, Mail Stop RL11, 800 W. Campbell Road, Richardson, TX 75080, USA
| | - Grant Shoffner
- Department of Biological Chemistry, David Geffen School of Medicine, University of California, Los Angeles, CA 90095, USA
| | - Feng Guo
- Department of Biological Chemistry, David Geffen School of Medicine, University of California, Los Angeles, CA 90095, USA
| | - Li Zhang
- Department of Biological Sciences, University of Texas at Dallas, Mail Stop RL11, 800 W. Campbell Road, Richardson, TX 75080, USA
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Ivanova IG, Park CV, Kenneth NS. Translating the Hypoxic Response-the Role of HIF Protein Translation in the Cellular Response to Low Oxygen. Cells 2019; 8:cells8020114. [PMID: 30717305 PMCID: PMC6406544 DOI: 10.3390/cells8020114] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2019] [Revised: 01/29/2019] [Accepted: 01/30/2019] [Indexed: 12/11/2022] Open
Abstract
Hypoxia-Inducible Factors (HIFs) play essential roles in the physiological response to low oxygen in all multicellular organisms, while their deregulation is associated with human diseases. HIF levels and activity are primarily controlled by the availability of the oxygen-sensitive HIFα subunits, which is mediated by rapid alterations to the rates of HIFα protein production and degradation. While the pathways that control HIFα degradation are understood in great detail, much less is known about the targeted control of HIFα protein synthesis and what role this has in controlling HIF activity during the hypoxic response. This review will focus on the signalling pathways and RNA binding proteins that modulate HIFα mRNA half-life and/or translation rate, and their contribution to hypoxia-associated diseases.
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Affiliation(s)
- Iglika G Ivanova
- Institute for Cell and Molecular Biosciences, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, NE2 4HH, UK.
| | - Catherine V Park
- Institute for Cell and Molecular Biosciences, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, NE2 4HH, UK.
| | - Niall S Kenneth
- Institute for Cell and Molecular Biosciences, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, NE2 4HH, UK.
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Pérez-Cañamás M, Hernández C. New Insights into the Nucleolar Localization of a Plant RNA Virus-Encoded Protein That Acts in Both RNA Packaging and RNA Silencing Suppression: Involvement of Importins Alpha and Relevance for Viral Infection. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2018; 31:1134-1144. [PMID: 29781763 DOI: 10.1094/mpmi-02-18-0050-r] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Despite the fact that replication of plus-strand RNA viruses takes place in the cytoplasm of host cells, different proteins encoded by these infectious agents have been shown to localize in the nucleus, with high accumulation at the nucleolus. In most cases, the molecular determinants or biological significance of such subcellular localization remains elusive. Recently, we reported that protein p37 encoded by Pelargonium line pattern virus (family Tombusviridae) acts in both RNA packaging and RNA silencing suppression. Consistently with these functions, p37 was detected in the cytoplasm of plant cells, although it was also present in the nucleus and, particularly, in the nucleolus. Here, we searched for further insights into factors influencing p37 nucleolar localization and into its potential relevance for viral infection. Besides mapping the protein region containing the nucleolar localization signal, we have found that p37 interacts with distinct members of the importin alpha family-main cellular transporters for nucleo-cytoplasmic traffic of proteins-and that these interactions are crucial for nucleolar targeting of p37. Impairment of p37 nucleolar localization through downregulation of importin alpha expression resulted in a reduction of viral accumulation, suggesting that sorting of the protein to the major subnuclear compartment is advantageous for the infection process.
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Affiliation(s)
- Miryam Pérez-Cañamás
- Instituto de Biología Molecular y Celular de Plantas (Consejo Superior de Investigaciones Científicas-Universidad Politécnica de Valencia). Ciudad Politécnica de la Innovación, Ed. 8E. Camino de Vera s/n, 46022 Valencia, Spain
| | - Carmen Hernández
- Instituto de Biología Molecular y Celular de Plantas (Consejo Superior de Investigaciones Científicas-Universidad Politécnica de Valencia). Ciudad Politécnica de la Innovación, Ed. 8E. Camino de Vera s/n, 46022 Valencia, Spain
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Mendes M, Peláez-García A, López-Lucendo M, Bartolomé RA, Calviño E, Barderas R, Casal JI. Mapping the Spatial Proteome of Metastatic Cells in Colorectal Cancer. Proteomics 2017; 17. [DOI: 10.1002/pmic.201700094] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2017] [Revised: 07/28/2017] [Indexed: 12/27/2022]
Affiliation(s)
- Marta Mendes
- Department of Cellular and Molecular Medicine; Centro de Investigaciones Biológicas (CIB-CSIC); Madrid Spain
| | - Alberto Peláez-García
- Department of Cellular and Molecular Medicine; Centro de Investigaciones Biológicas (CIB-CSIC); Madrid Spain
| | - María López-Lucendo
- Department of Cellular and Molecular Medicine; Centro de Investigaciones Biológicas (CIB-CSIC); Madrid Spain
| | - Rubén A. Bartolomé
- Department of Cellular and Molecular Medicine; Centro de Investigaciones Biológicas (CIB-CSIC); Madrid Spain
| | - Eva Calviño
- Department of Cellular and Molecular Medicine; Centro de Investigaciones Biológicas (CIB-CSIC); Madrid Spain
| | - Rodrigo Barderas
- Department of Cellular and Molecular Medicine; Centro de Investigaciones Biológicas (CIB-CSIC); Madrid Spain
- Instituto de Salud Carlos III.; Majadahonda Spain
| | - J. Ignacio Casal
- Department of Cellular and Molecular Medicine; Centro de Investigaciones Biológicas (CIB-CSIC); Madrid Spain
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Scott CA, Marsden AN, Rebagliati MR, Zhang Q, Chamling X, Searby CC, Baye LM, Sheffield VC, Slusarski DC. Nuclear/cytoplasmic transport defects in BBS6 underlie congenital heart disease through perturbation of a chromatin remodeling protein. PLoS Genet 2017; 13:e1006936. [PMID: 28753627 PMCID: PMC5550010 DOI: 10.1371/journal.pgen.1006936] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2017] [Revised: 08/09/2017] [Accepted: 07/20/2017] [Indexed: 01/31/2023] Open
Abstract
Mutations in BBS6 cause two clinically distinct syndromes, Bardet-Biedl syndrome (BBS), a syndrome caused by defects in cilia transport and function, as well as McKusick-Kaufman syndrome, a genetic disorder characterized by congenital heart defects. Congenital heart defects are rare in BBS, and McKusick-Kaufman syndrome patients do not develop retinitis pigmentosa. Therefore, the McKusick-Kaufman syndrome allele may highlight cellular functions of BBS6 distinct from the presently understood functions in the cilia. In support, we find that the McKusick-Kaufman syndrome disease-associated allele, BBS6H84Y; A242S, maintains cilia function. We demonstrate that BBS6 is actively transported between the cytoplasm and nucleus, and that BBS6H84Y; A242S, is defective in this transport. We developed a transgenic zebrafish with inducible bbs6 to identify novel binding partners of BBS6, and we find interaction with the SWI/SNF chromatin remodeling protein Smarcc1a (SMARCC1 in humans). We demonstrate that through this interaction, BBS6 modulates the sub-cellular localization of SMARCC1 and find, by transcriptional profiling, similar transcriptional changes following smarcc1a and bbs6 manipulation. Our work identifies a new function for BBS6 in nuclear-cytoplasmic transport, and provides insight into the disease mechanism underlying the congenital heart defects in McKusick-Kaufman syndrome patients. To understand how mutations in one gene can cause two distinct human syndromes (McKusick-Kaufman syndrome and Bardet-Bield syndrome), we investigated the cellular functions of the implicated gene BBS6. We found that BBS6 is actively transported between the cytoplasm and nucleus, and this interaction is disrupted in McKusick-Kaufman syndrome, but not Bardet-Biedl syndrome. We find that by manipulating BBS6, we can affect another protein, SMARCC1, which has a direct role in regulating gene expression. When we profiled these changes in gene expression, we find that many genes, which can be directly linked to the symptoms of McKusick-Kaufman syndrome, are affected. Therefore, our data support that the nuclear-cytoplasmic transport defect of BBS6, through disruption of proteins controlling gene expression, cause the symptoms observed in McKusick-Kaufman syndrome patients.
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Affiliation(s)
- Charles Anthony Scott
- Department of Biology, University of Iowa, Iowa City, Iowa, United States of America
| | - Autumn N. Marsden
- Department of Biology, University of Iowa, Iowa City, Iowa, United States of America
- Interdisciplinary Graduate Program in Genetics, University of Iowa, Iowa City, Iowa, United States of America
| | - Michael R. Rebagliati
- Department of Biology, University of Iowa, Iowa City, Iowa, United States of America
| | - Qihong Zhang
- Department of Pediatrics and Ophthalmology, Carver College of Medicine, University of Iowa, Iowa City, Iowa, United States of America
| | - Xitiz Chamling
- Department of Pediatrics and Ophthalmology, Carver College of Medicine, University of Iowa, Iowa City, Iowa, United States of America
| | - Charles C. Searby
- Department of Pediatrics and Ophthalmology, Carver College of Medicine, University of Iowa, Iowa City, Iowa, United States of America
| | - Lisa M. Baye
- Department of Biology, University of Iowa, Iowa City, Iowa, United States of America
| | - Val C. Sheffield
- Department of Pediatrics and Ophthalmology, Carver College of Medicine, University of Iowa, Iowa City, Iowa, United States of America
- Wynn Institute for Vision Research University of Iowa, Iowa City, Iowa, United States of America
| | - Diane C. Slusarski
- Department of Biology, University of Iowa, Iowa City, Iowa, United States of America
- Wynn Institute for Vision Research University of Iowa, Iowa City, Iowa, United States of America
- * E-mail:
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Neethling A, Mouton J, Loos B, Corfield V, de Villiers C, Kinnear C. Filamin C: a novel component of the KCNE2 interactome during hypoxia. Cardiovasc J Afr 2016; 27:4-11. [PMID: 26956495 PMCID: PMC4816932 DOI: 10.5830/cvja-2015-049] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2014] [Accepted: 05/17/2015] [Indexed: 12/16/2022] Open
Abstract
Aim KCNE2 encodes for the potassium voltage-gated channel, KCNE2. Mutations in KCNE2 have been associated with long-QT syndrome (LQTS). While KCNE2 has been extensively studied, the functions of its C-terminal domain remain inadequately described. Here, we aimed to elucidate the functions of this domain by identifying its protein interactors using yeast two-hybrid analysis. Methods The C-terminal domain of KCNE2 was used as bait to screen a human cardiac cDNA library for putative interacting proteins. Co-localisation and co-immunoprecipitation analyses were used for verification. Results Filamin C (FLNC) was identified as a putative interactor with KCNE2. FLNC and KCNE2 co-localised within the cell, however, a physical interaction was only observed under hypoxic conditions. Conclusion The identification of FLNC as a novel KCNE2 ligand not only enhances current understanding of ion channel function and regulation, but also provides valuable information about possible pathways likely to be involved in LQTS pathogenesis.
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Affiliation(s)
- Annika Neethling
- DST/NRF Centre of Excellence in Biomedical Tuberculosis Research, SA MRC Centre for Tuberculosis Research, Division of Molecular Biology and Human Genetics, Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, Stellenbosch University, South Africa
| | - Jomien Mouton
- DST/NRF Centre of Excellence in Biomedical Tuberculosis Research, SA MRC Centre for Tuberculosis Research, Division of Molecular Biology and Human Genetics, Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, Stellenbosch University, South Africa
| | - Ben Loos
- Department of Physiological Sciences, Faculty of Science, Stellenbosch University, Stellenbosch, South Africa
| | - Valerie Corfield
- DST/NRF Centre of Excellence in Biomedical Tuberculosis Research, SA MRC Centre for Tuberculosis Research, Division of Molecular Biology and Human Genetics, Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, Stellenbosch University, South Africa
| | - Carin de Villiers
- DST/NRF Centre of Excellence in Biomedical Tuberculosis Research, SA MRC Centre for Tuberculosis Research, Division of Molecular Biology and Human Genetics, Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, Stellenbosch University, South Africa
| | - Craig Kinnear
- DST/NRF Centre of Excellence in Biomedical Tuberculosis Research, SA MRC Centre for Tuberculosis Research, Division of Molecular Biology and Human Genetics, Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, Stellenbosch University, South Africa
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The Swi3 protein plays a unique role in regulating respiration in eukaryotes. Biosci Rep 2016; 36:BSR20160083. [PMID: 27190130 PMCID: PMC5293592 DOI: 10.1042/bsr20160083] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2016] [Accepted: 05/17/2016] [Indexed: 01/08/2023] Open
Abstract
Recent experimental evidence increasingly shows that the dysregulation of cellular bioenergetics is associated with a wide array of common human diseases, including cancer, neurological diseases and diabetes. Respiration provides a vital source of cellular energy for most eukaryotic cells, particularly high energy demanding cells. However, the understanding of how respiration is globally regulated is very limited. Interestingly, recent evidence suggests that Swi3 is an important regulator of respiration genes in yeast. In this report, we performed an array of biochemical and genetic experiments and computational analysis to directly evaluate the function of Swi3 and its human homologues in regulating respiration. First, we showed, by computational analysis and measurements of oxygen consumption and promoter activities, that Swi3, not Swi2, regulates genes encoding functions involved in respiration and oxygen consumption. Biochemical analysis showed that the levels of mitochondrial respiratory chain complexes were substantially increased in Δswi3 cells, compared with the parent cells. Additionally, our data showed that Swi3 strongly affects haem/oxygen-dependent activation of respiration gene promoters whereas Swi2 affects only the basal, haem-independent activities of these promoters. We found that increased expression of aerobic expression genes is correlated with increased oxygen consumption and growth rates in Δswi3 cells in air. Furthermore, using computational analysis and RNAi knockdown, we showed that the mammalian Swi3 BAF155 and BAF170 regulate respiration in HeLa cells. Together, these experimental and computational data demonstrated that Swi3 and its mammalian homologues are key regulators in regulating respiration.
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Tang Q, Huang W, Guan J, Jin L, Che T, Fu Y, Hu Y, Tian S, Wang D, Jiang Z, Li X, Li M. Transcriptomic analysis provides insight into high-altitude acclimation in domestic goats. Gene 2015; 567:208-16. [PMID: 25958351 DOI: 10.1016/j.gene.2015.05.007] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2015] [Revised: 04/27/2015] [Accepted: 05/01/2015] [Indexed: 10/23/2022]
Abstract
Domestic goats are distributed in a wide range of habitats and have acclimated to their local environmental conditions. To investigate the gene expression changes of goats that are induced by high altitude stress, we performed RNA-seq on 27 samples from the three hypoxia-sensitive tissues (heart, lung, and skeletal muscle) in three indigenous populations from distinct altitudes (600 m, 2000 m, and 3000 m). We generated 129Gb of high-quality sequencing data (~4Gb per sample) and catalogued the expression profiles of 12,421 annotated hircine genes in each sample. The analysis showed global similarities and differences of high-altitude transcriptomes among populations and tissues as well as revealed that the heart underwent the most high-altitude induced expression changes. We identified numerous differentially expressed genes that exhibited distinct expression patterns, and nonsynonymous single nucleotide variant-containing genes that were highly differentiated between the high- and low-altitude populations. These genes have known or potential roles in hypoxia response and were enriched in functional gene categories potentially responsible for high-altitude stress. Therefore, they are appealing candidates for further investigation of the gene expression and associated regulatory mechanisms related to high-altitude acclimation.
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Affiliation(s)
- Qianzi Tang
- Institute of Animal Genetics and Breeding, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu 611130, China; Farm Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province, Sichuan Agricultural University, Chengdu 611130, China
| | - Wenyao Huang
- Institute of Animal Genetics and Breeding, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu 611130, China; Farm Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province, Sichuan Agricultural University, Chengdu 611130, China
| | - Jiuqiang Guan
- Sichuan Academy of Grassland Science, Chengdu 611731, China
| | - Long Jin
- Institute of Animal Genetics and Breeding, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu 611130, China; Farm Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province, Sichuan Agricultural University, Chengdu 611130, China
| | - Tiandong Che
- Institute of Animal Genetics and Breeding, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu 611130, China; Farm Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province, Sichuan Agricultural University, Chengdu 611130, China
| | - Yuhua Fu
- Institute of Animal Genetics and Breeding, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu 611130, China; Farm Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province, Sichuan Agricultural University, Chengdu 611130, China; Key Lab of Animal Genetics, Breeding and Reproduction of Ministry Education, Huazhong Agricultural University, Wuhan 430070, China
| | - Yaodong Hu
- Institute of Animal Genetics and Breeding, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu 611130, China; Farm Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province, Sichuan Agricultural University, Chengdu 611130, China
| | - Shilin Tian
- Novogene Bioinformatics Institute, Beijing 100083, China
| | - Dawei Wang
- Novogene Bioinformatics Institute, Beijing 100083, China
| | - Zhi Jiang
- Novogene Bioinformatics Institute, Beijing 100083, China
| | - Xuewei Li
- Institute of Animal Genetics and Breeding, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu 611130, China; Farm Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province, Sichuan Agricultural University, Chengdu 611130, China
| | - Mingzhou Li
- Institute of Animal Genetics and Breeding, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu 611130, China; Farm Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province, Sichuan Agricultural University, Chengdu 611130, China.
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Pinto G, Alhaiek AAM, Godovac-Zimmermann J. Proteomics reveals the importance of the dynamic redistribution of the subcellular location of proteins in breast cancer cells. Expert Rev Proteomics 2015; 12:61-74. [PMID: 25591448 DOI: 10.1586/14789450.2015.1002474] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
At the molecular level, living cells are enormously complicated complex adaptive systems in which intertwined genomic, transcriptomic, proteomic and metabolic networks all play a crucial role. At the same time, cells are spatially heterogeneous systems in which subcellular compartmentalization of different functions is ubiquitous and requires efficient cross-compartmental communication. Dynamic redistribution of multitudinous proteins to different subcellular locations in response to cellular functional state is increasingly recognized as a crucial characteristic of cellular function that seems to be at least as important as overall changes in protein abundance. Characterization of the subcellular spatial dynamics of protein distribution is a major challenge for proteomics and recent results with MCF7 breast cancer cells suggest that this may be of particular importance for cancer cells.
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Affiliation(s)
- Gabriella Pinto
- Division of Medicine, University College London, Centre for Nephrology, Royal Free Campus, Rowland Hill Street, London NW3 2PF, UK
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14
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Baqader NO, Radulovic M, Crawford M, Stoeber K, Godovac-Zimmermann J. Nuclear cytoplasmic trafficking of proteins is a major response of human fibroblasts to oxidative stress. J Proteome Res 2014; 13:4398-423. [PMID: 25133973 PMCID: PMC4259009 DOI: 10.1021/pr500638h] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
We have used a subcellular spatial razor approach based on LC-MS/MS-based proteomics with SILAC isotope labeling to determine changes in protein abundances in the nuclear and cytoplasmic compartments of human IMR90 fibroblasts subjected to mild oxidative stress. We show that response to mild tert-butyl hydrogen peroxide treatment includes redistribution between the nucleus and cytoplasm of numerous proteins not previously associated with oxidative stress. The 121 proteins with the most significant changes encompass proteins with known functions in a wide variety of subcellular locations and of cellular functional processes (transcription, signal transduction, autophagy, iron metabolism, TCA cycle, ATP synthesis) and are consistent with functional networks that are spatially dispersed across the cell. Both nuclear respiratory factor 2 and the proline regulatory axis appear to contribute to the cellular metabolic response. Proteins involved in iron metabolism or with iron/heme as a cofactor as well as mitochondrial proteins are prominent in the response. Evidence suggesting that nuclear import/export and vesicle-mediated protein transport contribute to the cellular response was obtained. We suggest that measurements of global changes in total cellular protein abundances need to be complemented with measurements of the dynamic subcellular spatial redistribution of proteins to obtain comprehensive pictures of cellular function.
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Affiliation(s)
- Noor O. Baqader
- Division of Medicine, Center for Nephrology, University College London, Royal Free Campus, Rowland Hill Street, London NW3 2PF, United Kingdom
| | - Marko Radulovic
- Division of Medicine, Center for Nephrology, University College London, Royal Free Campus, Rowland Hill Street, London NW3 2PF, United Kingdom
- Insitute of Oncology and Radiology, Pasterova 14, 11000 Belgrade, Serbia
| | - Mark Crawford
- Division of Medicine, Center for Nephrology, University College London, Royal Free Campus, Rowland Hill Street, London NW3 2PF, United Kingdom
| | - Kai Stoeber
- Research Department of Pathology and UCL Cancer Institute, Rockefeller Building, University College London, University Street, London WC1E 6JJ, United Kingdom
| | - Jasminka Godovac-Zimmermann
- Division of Medicine, Center for Nephrology, University College London, Royal Free Campus, Rowland Hill Street, London NW3 2PF, United Kingdom
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15
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Pinto G, Alhaiek AAM, Amadi S, Qattan AT, Crawford M, Radulovic M, Godovac-Zimmermann J. Systematic nucleo-cytoplasmic trafficking of proteins following exposure of MCF7 breast cancer cells to estradiol. J Proteome Res 2014; 13:1112-27. [PMID: 24422525 DOI: 10.1021/pr4012359] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
We have used a proteomics subcellular spatial razor approach to look at changes in total protein abundance and in protein distribution between the nucleus and cytoplasm following exposure of MCF7 breast cancer cells to estradiol. The dominant response of MCF7 cells to estrogen stimulation involves dynamic changes in protein subcellular spatial distribution rather than changes in total protein abundance. Of the 3604 quantitatively monitored proteins, only about 2% show substantial changes in total abundance (>2-fold), whereas about 20% of the proteins show substantial changes in local abundance and/or redistribution of their subcellular location, with up to 16-fold changes in their local concentration in the nucleus or the cytoplasm. We propose that dynamic redistribution of the subcellular location of multiple proteins in response to stimuli is a fundamental characteristic of cells and suggest that perturbation of cellular spatial control may be an important feature of cancer.
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Affiliation(s)
- Gabriella Pinto
- Proteomics and Molecular Cell Dynamics, Center for Nephrology, Division of Medicine, School of Life and Medical Sciences, University College London , Royal Free Campus, Rowland Hill Street, London NW3 2PF, United Kingdom
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16
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Pérez de Diego R, Mulvey C, Casanova JL, Godovac-Zimmermann J. Proteomics in immunity and herpes simplex encephalitis. Expert Rev Proteomics 2013; 11:21-9. [PMID: 24351021 DOI: 10.1586/14789450.2014.864954] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
The genetic theory of infectious diseases has proposed that susceptibility to life-threatening infectious diseases in childhood, occurring in the course of primary infection, results mostly from individually rare but collectively diverse single-gene variants. Recent evidence of an ever-expanding spectrum of genes involved in susceptibility to infectious disease indicates that the paradigm has important implications for diagnosis and treatment. One such pathology is childhood herpes simplex encephalitis, which shows a pattern of rare but diverse disease-disposing genetic variants. The present report shows how proteomics can help to understand susceptibility to childhood herpes simplex encephalitis and other viral infections, suggests that proteomics may have a particularly important role to play, emphasizes that variation over the population is a critical issue for proteomics and notes some new challenges for proteomics and related bioinformatics tools in the context of rare but diverse genetic defects.
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Affiliation(s)
- Rebeca Pérez de Diego
- Immunology Unit, IdiPAZ Institute for Health Research, La Paz University Hospital, 261 Pº Castellana, Madrid 28046, Spain
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17
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Spatial reorganization of Saccharomyces cerevisiae enolase to alter carbon metabolism under hypoxia. EUKARYOTIC CELL 2013; 12:1106-19. [PMID: 23748432 DOI: 10.1128/ec.00093-13] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Hypoxia has critical effects on the physiology of organisms. In the yeast Saccharomyces cerevisiae, glycolytic enzymes, including enolase (Eno2p), formed cellular foci under hypoxia. Here, we investigated the regulation and biological functions of these foci. Focus formation by Eno2p was inhibited temperature independently by the addition of cycloheximide or rapamycin or by the single substitution of alanine for the Val22 residue. Using mitochondrial inhibitors and an antioxidant, mitochondrial reactive oxygen species (ROS) production was shown to participate in focus formation. Focus formation was also inhibited temperature dependently by an SNF1 knockout mutation. Interestingly, the foci were observed in the cell even after reoxygenation. The metabolic turnover analysis revealed that [U-(13)C]glucose conversion to pyruvate and oxaloacetate was accelerated in focus-forming cells. These results suggest that under hypoxia, S. cerevisiae cells sense mitochondrial ROS and, by the involvement of SNF1/AMPK, spatially reorganize metabolic enzymes in the cytosol via de novo protein synthesis, which subsequently increases carbon metabolism. The mechanism may be important for yeast cells under hypoxia, to quickly provide both energy and substrates for the biosynthesis of lipids and proteins independently of the tricarboxylic acid (TCA) cycle and also to fit changing environments.
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Mulvey CM, Tudzarova S, Crawford M, Williams GH, Stoeber K, Godovac-Zimmermann J. Subcellular proteomics reveals a role for nucleo-cytoplasmic trafficking at the DNA replication origin activation checkpoint. J Proteome Res 2013; 12:1436-53. [PMID: 23320540 DOI: 10.1021/pr3010919] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Depletion of DNA replication initiation factors such as CDC7 kinase triggers the origin activation checkpoint in healthy cells and leads to a protective cell cycle arrest at the G1 phase of the mitotic cell division cycle. This protective mechanism is thought to be defective in cancer cells. To investigate how this checkpoint is activated and maintained in healthy cells, we conducted a quantitative SILAC analysis of the nuclear- and cytoplasmic-enriched compartments of CDC7-depleted fibroblasts and compared them to a total cell lysate preparation. Substantial changes in total abundance and/or subcellular location were detected for 124 proteins, including many essential proteins associated with DNA replication/cell cycle. Similar changes in protein abundance and subcellular distribution were observed for various metabolic processes, including oxidative stress, iron metabolism, protein translation and the tricarboxylic acid cycle. This is accompanied by reduced abundance of two karyopherin proteins, suggestive of reduced nuclear import. We propose that altered nucleo-cytoplasmic trafficking plays a key role in the regulation of cell cycle arrest. The results increase understanding of the mechanisms underlying maintenance of the DNA replication origin activation checkpoint and are consistent with our proposal that cell cycle arrest is an actively maintained process that appears to be distributed over various subcellular locations.
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Affiliation(s)
- Claire M Mulvey
- Division of Medicine, University College London , Royal Free Campus, Rowland Hill Street, London NW3 2PF, United Kingdom
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19
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Qattan AT, Radulovic M, Crawford M, Godovac-Zimmermann J. Spatial distribution of cellular function: the partitioning of proteins between mitochondria and the nucleus in MCF7 breast cancer cells. J Proteome Res 2012; 11:6080-101. [PMID: 23051583 PMCID: PMC4261608 DOI: 10.1021/pr300736v] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Concurrent proteomics analysis of the nuclei and mitochondria of MCF7 breast cancer cells identified 985 proteins (40% of all detected proteins) present in both organelles. Numerous proteins from all five complexes involved in oxidative phosphorylation (e.g., NDUFA5, NDUFB10, NDUFS1, NDUF2, SDHA, UQRB, UQRC2, UQCRH, COX5A, COX5B, MT-CO2, ATP5A1, ATP5B, ATP5H, etc.), from the TCA-cycle (DLST, IDH2, IDH3A, OGDH, SUCLAG2, etc.), and from glycolysis (ALDOA, ENO1, FBP1, GPI, PGK1, TALDO1, etc.) were distributed to both the nucleus and mitochondria. In contrast, proteins involved in nuclear/mitochondrial RNA processing/translation and Ras/Rab signaling showed different partitioning patterns. The identity of the OxPhos, TCA-cycle, and glycolysis proteins distributed to both the nucleus and mitochondria provides evidence for spatio-functional integration of these processes over the two different subcellular organelles. We suggest that there are unrecognized aspects of functional coordination between the nucleus and mitochondria, that integration of core functional processes via wide subcellular distribution of constituent proteins is a common characteristic of cells, and that subcellular spatial integration of function may be a vital aspect of cancer.
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Affiliation(s)
- Amal T. Qattan
- Proteomics and Molecular Cell Dynamics, Division of Medicine, School of Life and Medical Sciences, University College London, Royal Free Campus, Rowland Hill Street NW3 2PF, United Kingdom
| | - Marko Radulovic
- Proteomics and Molecular Cell Dynamics, Division of Medicine, School of Life and Medical Sciences, University College London, Royal Free Campus, Rowland Hill Street NW3 2PF, United Kingdom
| | - Mark Crawford
- Proteomics and Molecular Cell Dynamics, Division of Medicine, School of Life and Medical Sciences, University College London, Royal Free Campus, Rowland Hill Street NW3 2PF, United Kingdom
| | - Jasminka Godovac-Zimmermann
- Proteomics and Molecular Cell Dynamics, Division of Medicine, School of Life and Medical Sciences, University College London, Royal Free Campus, Rowland Hill Street NW3 2PF, United Kingdom
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20
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Dastidar RG, Hooda J, Shah A, Cao TM, Henke RM, Zhang L. The nuclear localization of SWI/SNF proteins is subjected to oxygen regulation. Cell Biosci 2012; 2:30. [PMID: 22932476 PMCID: PMC3489556 DOI: 10.1186/2045-3701-2-30] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2012] [Accepted: 08/17/2012] [Indexed: 12/15/2022] Open
Abstract
BACKGROUND Hypoxia is associated with many disease conditions in humans, such as cancer, stroke and traumatic injuries. Hypoxia elicits broad molecular and cellular changes in diverse eukaryotes. Our recent studies suggest that one likely mechanism mediating such broad changes is through changes in the cellular localization of important regulatory proteins. Particularly, we have found that over 120 nuclear proteins with important functions ranging from transcriptional regulation to RNA processing exhibit altered cellular locations under hypoxia. In this report, we describe further experiments to identify and evaluate the role of nuclear protein relocalization in mediating hypoxia responses in yeast. RESULTS To identify regulatory proteins that play a causal role in mediating hypoxia responses, we characterized the time courses of relocalization of hypoxia-altered nuclear proteins in response to hypoxia and reoxygenation. We found that 17 nuclear proteins relocalized in a significantly shorter time period in response to both hypoxia and reoxygenation. Particularly, several components of the SWI/SNF complex were fast responders, and analysis of gene expression data show that many targets of the SWI/SNF proteins are oxygen regulated. Furthermore, confocal fluorescent live cell imaging showed that over 95% of hypoxia-altered SWI/SNF proteins accumulated in the cytosol in hypoxic cells, while over 95% of the proteins were nuclear in normoxic cells, as expected. CONCLUSIONS SWI/SNF proteins relocalize in response to hypoxia and reoxygenation in a quick manner, and their relocalization likely accounts for, in part or in whole, oxygen regulation of many SWI/SNF target genes.
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Affiliation(s)
- Ranita Ghosh Dastidar
- Department of Molecular and Cell Biology, Center for Systems Biology, University of Texas at Dallas, Mail Stop RL11 800 W Campbell Road, Richardson, TX, 75080, USA
| | - Jagmohan Hooda
- Department of Molecular and Cell Biology, Center for Systems Biology, University of Texas at Dallas, Mail Stop RL11 800 W Campbell Road, Richardson, TX, 75080, USA
| | - Ajit Shah
- Department of Molecular and Cell Biology, Center for Systems Biology, University of Texas at Dallas, Mail Stop RL11 800 W Campbell Road, Richardson, TX, 75080, USA
| | - Thai M Cao
- Department of Molecular and Cell Biology, Center for Systems Biology, University of Texas at Dallas, Mail Stop RL11 800 W Campbell Road, Richardson, TX, 75080, USA
| | - Robert Michael Henke
- Department of Molecular and Cell Biology, Center for Systems Biology, University of Texas at Dallas, Mail Stop RL11 800 W Campbell Road, Richardson, TX, 75080, USA
| | - Li Zhang
- Department of Molecular and Cell Biology, Center for Systems Biology, University of Texas at Dallas, Mail Stop RL11 800 W Campbell Road, Richardson, TX, 75080, USA
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Thauerer B, Zur Nedden S, Baier-Bitterlich G. Purine nucleosides: endogenous neuroprotectants in hypoxic brain. J Neurochem 2012; 121:329-42. [PMID: 22335456 PMCID: PMC3499684 DOI: 10.1111/j.1471-4159.2012.07692.x] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Even a short blockade of oxygen flow in brain may lead to the inhibition of oxidative phosphorylation and depletion of cellular ATP, which results in profound deficiencies in cellular function. Following ischemia, dying, injured, and hypoxic cells release soluble purine-nucleotide and -nucleoside pools. Growing evidence suggests that purine nucleosides might act as trophic factors in the CNS and PNS. In addition to equilibrative nucleoside transporters (ENTs) regulating purine nucleoside concentrations intra- and extracellularly, specific extracellular receptor subtypes for these compounds are expressed on neurons, glia, and endothelial cells, mediating stunningly diverse effects. Such effects range from induction of cell differentiation, apoptosis, mitogenesis, and morphogenetic changes, to stimulation of synthesis and/or release of cytokines and neurotrophic factors under both physiological and pathological conditions. Multiple signaling pathways regulate the critical balance between cell death and survival in hypoxia-ischemia. A convergent pathway for the regulation of multiple modalities involved in O₂ sensing is the mitogen activated protein kinase (p42/44 MAPK) or (ERK1/2 extracellular signal-regulated kinases) pathway terminating in a variety of transcription factors, for example, hypoxia-inducible factor 1α. In this review, the coherence of purine nucleoside-related pathways and MAPK activation in the endogenous neuroprotective regulation of the nervous system's development and neuroplasticity under hypoxic stress will be discussed.
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Affiliation(s)
- Bettina Thauerer
- Division of Neurobiochemistry, Biocenter Department, Medical University of Innsbruck, Innsbruck, Austria
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