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Qin J, Garus A, Autexier C. The C-terminal extension of dyskerin is a dyskeratosis congenita mutational hotspot that modulates interaction with telomerase RNA and subcellular localization. Hum Mol Genet 2024; 33:318-332. [PMID: 37879098 PMCID: PMC10840380 DOI: 10.1093/hmg/ddad180] [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: 08/24/2023] [Revised: 10/09/2023] [Accepted: 10/20/2023] [Indexed: 10/27/2023] Open
Abstract
Dyskerin is a component of the human telomerase complex and is involved in stabilizing the human telomerase RNA (hTR). Many mutations in the DKC1 gene encoding dyskerin are found in X-linked dyskeratosis congenita (X-DC), a premature aging disorder and other related diseases. The C-terminal extension (CTE) of dyskerin contributes to its interaction with the molecular chaperone SHQ1 during the early stage of telomerase biogenesis. Disease mutations in this region were proposed to disrupt dyskerin-SHQ1 interaction and destabilize dyskerin, reducing hTR levels indirectly. However, biochemical evidence supporting this hypothesis is still lacking. In addition, the effects of many CTE disease mutations on hTR have not been examined. In this study, we tested eight dyskerin CTE variants and showed that they failed to maintain hTR levels. These mutants showed slightly reduced but not abolished interaction with SHQ1, and caused defective binding to hTR. Deletion of the CTE further reduced binding to hTR, and perturbed localization of dyskerin to the Cajal bodies and the nucleolus, and the interaction with TCAB1 as well as GAR1. Our findings suggest impaired dyskerin-hTR interaction in cells as a previously overlooked mechanism through which dyskerin CTE mutations cause X-DC and related telomere syndromes.
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Affiliation(s)
- Jian Qin
- Department of Anatomy and Cell Biology, McGill University, 3640 University Street, Montreal, Quebec, QC H3A 0C7, Canada
- Lady Davis Institute, Jewish General Hospital, 3755 Chem, de la Côte-Sainte-Catherine, Montréal, QC H3T 1E2, Canada
| | - Alexandre Garus
- Department of Anatomy and Cell Biology, McGill University, 3640 University Street, Montreal, Quebec, QC H3A 0C7, Canada
- Lady Davis Institute, Jewish General Hospital, 3755 Chem, de la Côte-Sainte-Catherine, Montréal, QC H3T 1E2, Canada
| | - Chantal Autexier
- Department of Anatomy and Cell Biology, McGill University, 3640 University Street, Montreal, Quebec, QC H3A 0C7, Canada
- Lady Davis Institute, Jewish General Hospital, 3755 Chem, de la Côte-Sainte-Catherine, Montréal, QC H3T 1E2, Canada
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2
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Klump BM, Schmidt JC. Advances in understanding telomerase assembly. Biochem Soc Trans 2023; 51:2093-2101. [PMID: 38108475 PMCID: PMC10754283 DOI: 10.1042/bst20230269] [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: 09/05/2023] [Revised: 11/30/2023] [Accepted: 12/04/2023] [Indexed: 12/19/2023]
Abstract
Telomerase is a complex ribonucleoprotein scaffolded by the telomerase RNA (TR). Telomere lengthening by telomerase is essential to maintain the proliferative potential of stem cells and germ cells, and telomerase is inappropriately activated in the majority of cancers. Assembly of TR with its 12 protein co-factors and the maturation of the 5'- and 3'-ends of TR have been the focus of intense research efforts over the past two decades. High-resolution Cryo-EM structures of human telomerase, high-throughput sequencing of the 3' end of TR, and live cell imaging of various telomerase components have significantly advanced our understanding of the molecular mechanisms that govern telomerase biogenesis, yet many important questions remain unaddressed. In this review, we will summarize these recent advances and highlight the remaining key questions with the ultimate goal of targeting telomerase assembly to suppress telomere maintenance in cancer cells or to promote telomerase activity in patients affected by telomere shortening disorders.
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Affiliation(s)
- Basma M. Klump
- Institute for Quantitative Health Sciences and Engineering, Michigan State University, East Lansing, MI, U.S.A
- College of Osteopathic Medicine, Michigan State University, East Lansing, MI, U.S.A
- Cell and Molecular Biology Graduate Program, College of Natural Sciences, Michigan State University, East Lansing, MI, U.S.A
| | - Jens C. Schmidt
- Institute for Quantitative Health Sciences and Engineering, Michigan State University, East Lansing, MI, U.S.A
- Department of Obstetrics, Gynecology, and Reproductive Biology, Michigan State University, East Lansing, MI, U.S.A
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3
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Francia MG, Verneri P, Oses C, Vazquez Echegaray C, Garcia MR, Toro A, Levi V, Guberman AS. AKT1 induces Nanog promoter in a SUMOylation-dependent manner in different pluripotent contexts. BMC Res Notes 2023; 16:309. [PMID: 37919788 PMCID: PMC10623886 DOI: 10.1186/s13104-023-06598-3] [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: 01/31/2023] [Accepted: 10/26/2023] [Indexed: 11/04/2023] Open
Abstract
AKT/PKB is a kinase crucial for pluripotency maintenance in pluripotent stem cells. Multiple post-translational modifications modulate its activity. We have previously demonstrated that AKT1 induces the expression of the pluripotency transcription factor Nanog in a SUMOylation-dependent manner in mouse embryonic stem cells. Here, we studied different cellular contexts and main candidates that could mediate this induction. Our results strongly suggest the pluripotency transcription factors OCT4 and SOX2 are not essential mediators. Additionally, we concluded that this induction takes place in different pluripotent contexts but not in terminally differentiated cells. Finally, the cross-matching analysis of ESCs, iPSCs and MEFs transcriptomes and AKT1 phosphorylation targets provided new clues about possible factors that could be involved in the SUMOylation-dependent Nanog induction by AKT.
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Affiliation(s)
- Marcos Gabriel Francia
- Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales (IQUIBICEN), Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales, CONICET, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Paula Verneri
- Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales (IQUIBICEN), Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales, CONICET, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Camila Oses
- Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales (IQUIBICEN), Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales, CONICET, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Camila Vazquez Echegaray
- Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales (IQUIBICEN), Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales, CONICET, Universidad de Buenos Aires, Buenos Aires, Argentina
- Lund Stem Cell Center, Department of Molecular Medicine and Gene Therapy, Lund University, Lund, Sweden
| | - Mora Reneé Garcia
- Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales (IQUIBICEN), Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales, CONICET, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Ayelen Toro
- Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales (IQUIBICEN), Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales, CONICET, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Valeria Levi
- Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales (IQUIBICEN), Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales, CONICET, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Alejandra Sonia Guberman
- Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales (IQUIBICEN), Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales, CONICET, Universidad de Buenos Aires, Buenos Aires, Argentina.
- Departamento de Fisiología y Biología Molecular y Celular, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina.
- Laboratorio de Regulación Génica en Células Madre (CONICET-UBA), Intendente Guiraldes 2160 Pab. 2, 4to Piso, QB-71, C1428EGA, Buenos Aires, Argentina.
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4
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Lavering ED, Gandhamaneni M, Weeks DL. Intrinsically disordered regions are not sufficient to direct the compartmental localization of nucleolar proteins in the nucleus. PLoS Biol 2023; 21:e3002378. [PMID: 37943867 PMCID: PMC10662738 DOI: 10.1371/journal.pbio.3002378] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2023] [Revised: 11/21/2023] [Accepted: 10/12/2023] [Indexed: 11/12/2023] Open
Abstract
The nucleolus is a non-membrane bound organelle central to ribosome biogenesis. The nucleolus contains a mix of proteins and RNA and has 3 known nucleolar compartments: the fibrillar center (FC), the dense fibrillar component (DFC), and the granular component (GC). The spatial organization of the nucleolus is influenced by the phase separation properties of nucleolar proteins, the presence of RNA, protein modification, and cellular activity. Many nucleolar proteins appear to concentrate within the borders of the compartments. We investigated whether the intrinsically disordered regions from several proteins provided the information needed to establish specific compartment localization using Xenopus laevis oocytes. For the proteins we tested, the disordered regions were not sufficient to direct specific domain localization and appear dispensable with respect to compartmentalization. Among the proteins that colocalize to the DFC are the quartet that comprise the box H/ACA pseudouridylation complex. In contrast to the insufficiency of IDRs to direct compartment localization, we found that the DFC accumulation of 2 box H/ACA proteins, Gar1 and Nhp2, was disrupted by mutations that were previously shown to reduce their ability to join the box H/ACA complex. Using a nanobody to introduce novel binding to a different DFC localized protein, we restored the localization of the mutated forms of Gar1 and Nhp2.
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Affiliation(s)
- Emily D. Lavering
- Biochemistry and Molecular Biology Department, Carver College of Medicine, University of Iowa, Iowa City, United States of America
| | | | - Daniel L. Weeks
- Biochemistry and Molecular Biology Department, Carver College of Medicine, University of Iowa, Iowa City, United States of America
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Belli V, Maiello D, Di Lorenzo C, Furia M, Vicidomini R, Turano M. New Insights into Dyskerin-CypA Interaction: Implications for X-Linked Dyskeratosis Congenita and Beyond. Genes (Basel) 2023; 14:1766. [PMID: 37761906 PMCID: PMC10531313 DOI: 10.3390/genes14091766] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2023] [Revised: 08/27/2023] [Accepted: 09/04/2023] [Indexed: 09/29/2023] Open
Abstract
The highly conserved family of cyclophilins comprises multifunctional chaperones that interact with proteins and RNAs, facilitating the dynamic assembly of multimolecular complexes involved in various cellular processes. Cyclophilin A (CypA), the predominant member of this family, exhibits peptidyl-prolyl cis-trans isomerase activity. This enzymatic function aids with the folding and activation of protein structures and often serves as a molecular regulatory switch for large multimolecular complexes, ensuring appropriate inter- and intra-molecular interactions. Here, we investigated the involvement of CypA in the nucleus, where it plays a crucial role in supporting the assembly and trafficking of heterogeneous ribonucleoproteins (RNPs). We reveal that CypA is enriched in the nucleolus, where it colocalizes with the pseudouridine synthase dyskerin, the catalytic component of the multifunctional H/ACA RNPs involved in the modification of cellular RNAs and telomere stability. We show that dyskerin, whose mutations cause the X-linked dyskeratosis (X-DC) and the Hoyeraal-Hreidarsson congenital ribosomopathies, can directly interact with CypA. These findings, together with the remark that substitution of four dyskerin prolines are known to cause X-DC pathogenic mutations, lead us to indicate this protein as a CypA client. The data presented here suggest that this chaperone can modulate dyskerin activity influencing all its partecipated RNPs.
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Affiliation(s)
- Valentina Belli
- Istituto Nazionale Tumori—IRCSS—Fondazione G. Pascale, 80131 Naples, Italy;
| | - Daniela Maiello
- Department of Biology, University of Naples Federico II, 80126 Naples, Italy; (D.M.); (C.D.L.); (M.F.)
| | - Concetta Di Lorenzo
- Department of Biology, University of Naples Federico II, 80126 Naples, Italy; (D.M.); (C.D.L.); (M.F.)
- Department of Advanced Medical and Surgical Sciences, University of Campania “Luigi Vanvitelli”, 80138 Naples, Italy
| | - Maria Furia
- Department of Biology, University of Naples Federico II, 80126 Naples, Italy; (D.M.); (C.D.L.); (M.F.)
| | - Rosario Vicidomini
- Section on Cellular Communication, Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), National Institutes of Health (NIH), Bethesda, MD 20892, USA
| | - Mimmo Turano
- Department of Biology, University of Naples Federico II, 80126 Naples, Italy; (D.M.); (C.D.L.); (M.F.)
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6
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Gabriel Francia M, Oses C, Lorena Roberti S, Reneé Garcia M, Helio Cozza L, Candelaria Diaz M, Levi V, Sonia Guberman A. SUMOylation and the oncogenic E17K mutation affect AKT1 subcellular distribution and impact on Nanog-binding dynamics to chromatin in embryonic stem cells. J Struct Biol 2023; 215:107961. [PMID: 37059313 DOI: 10.1016/j.jsb.2023.107961] [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: 12/26/2022] [Revised: 03/23/2023] [Accepted: 04/02/2023] [Indexed: 04/16/2023]
Abstract
AKT/PKB is a kinase involved in the regulation of a plethora of cell processes. Particularly, in embryonic stem cells (ESCs), AKT is crucial for the maintenance of pluripotency. Although the activation of this kinase relies on its recruitment to the cellular membrane and subsequent phosphorylation, multiple other post-translational modifications (PTMs), including SUMOylation, fine-tune its activity and target specificity. Since this PTM can also modify the localization and availability of different proteins, in this work we explored if SUMOylation impacts on the subcellular compartmentalization and distribution of AKT1 in ESCs. We found that this PTM does not affect AKT1 membrane recruitment, but it modifies the AKT1 nucleus/cytoplasm distribution, increasing its nuclear presence. Additionally, within this compartment, we found that AKT1 SUMOylation also impacts on the chromatin-binding dynamics of NANOG, a central pluripotency transcription factor. Remarkably, the oncogenic E17K AKT1 mutant produces major changes in all these parameters increasing the binding of NANOG to its targets, also in a SUMOylation dependent manner. These findings demonstrate that SUMOylation modulates AKT1 subcellular distribution, thus adding an extra layer of regulation of its function, possibly by affecting the specificity and interaction with its downstream targets.
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Affiliation(s)
- Marcos Gabriel Francia
- Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales (IQUIBICEN, CONICET-UBA), Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires. Ciudad Autónoma de Buenos Aires, Argentina
| | - Camila Oses
- Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales (IQUIBICEN, CONICET-UBA), Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires. Ciudad Autónoma de Buenos Aires, Argentina
| | - Sabrina Lorena Roberti
- Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales (IQUIBICEN, CONICET-UBA), Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires. Ciudad Autónoma de Buenos Aires, Argentina
| | - Mora Reneé Garcia
- Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales (IQUIBICEN, CONICET-UBA), Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires. Ciudad Autónoma de Buenos Aires, Argentina
| | - Lucas Helio Cozza
- Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales (IQUIBICEN, CONICET-UBA), Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires. Ciudad Autónoma de Buenos Aires, Argentina
| | - Maria Candelaria Diaz
- Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales (IQUIBICEN, CONICET-UBA), Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires. Ciudad Autónoma de Buenos Aires, Argentina
| | - Valeria Levi
- Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales (IQUIBICEN, CONICET-UBA), Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires. Ciudad Autónoma de Buenos Aires, Argentina
| | - Alejandra Sonia Guberman
- Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales (IQUIBICEN, CONICET-UBA), Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires. Ciudad Autónoma de Buenos Aires, Argentina; Departamento de Fisiología y Biología Molecular y Celular, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires. Ciudad Autónoma de Buenos Aires, Argentina.
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7
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Post-Transcriptional and Post-Translational Modifications in Telomerase Biogenesis and Recruitment to Telomeres. Int J Mol Sci 2023; 24:ijms24055027. [PMID: 36902458 PMCID: PMC10003056 DOI: 10.3390/ijms24055027] [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: 02/02/2023] [Revised: 03/02/2023] [Accepted: 03/03/2023] [Indexed: 03/08/2023] Open
Abstract
Telomere length is associated with the proliferative potential of cells. Telomerase is an enzyme that elongates telomeres throughout the entire lifespan of an organism in stem cells, germ cells, and cells of constantly renewed tissues. It is activated during cellular division, including regeneration and immune responses. The biogenesis of telomerase components and their assembly and functional localization to the telomere is a complex system regulated at multiple levels, where each step must be tuned to the cellular requirements. Any defect in the function or localization of the components of the telomerase biogenesis and functional system will affect the maintenance of telomere length, which is critical to the processes of regeneration, immune response, embryonic development, and cancer progression. An understanding of the regulatory mechanisms of telomerase biogenesis and activity is necessary for the development of approaches toward manipulating telomerase to influence these processes. The present review focuses on the molecular mechanisms involved in the major steps of telomerase regulation and the role of post-transcriptional and post-translational modifications in telomerase biogenesis and function in yeast and vertebrates.
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8
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Lambert-Lanteigne P, Young A, Autexier C. Complex interaction network revealed by mutation of human telomerase 'insertion in fingers' and essential N-terminal domains and the telomere protein TPP1. J Biol Chem 2023; 299:102916. [PMID: 36649908 PMCID: PMC9958494 DOI: 10.1016/j.jbc.2023.102916] [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: 09/08/2022] [Revised: 01/05/2023] [Accepted: 01/06/2023] [Indexed: 01/15/2023] Open
Abstract
In the majority of human cancer cells, cellular immortalization depends on the maintenance of telomere length by telomerase. An essential step required for telomerase function is its recruitment to telomeres, which is regulated by the interaction of the telomere protein, TPP1, with the telomerase essential N-terminal (TEN) domain of the human telomerase reverse transcriptase, hTERT. We previously reported that the hTERT 'insertion in fingers domain' (IFD) recruits telomerase to telomeres in a TPP1-dependent manner. Here, we use hTERT truncations and the IFD domain containing mutations in conserved residues or premature aging disease-associated mutations to map the interactions between the IFD and TPP1. We find that the hTERT-IFD domain can interact with TPP1. However, deletion of the IFD motif in hTERT lacking the N-terminus and the C-terminal extension does not abolish interaction with TPP1, suggesting the IFD is not essential for hTERT interaction with TPP1. Several conserved residues in the central IFD-TRAP region that we reported regulate telomerase recruitment to telomeres, and cell immortalization compromise interaction of the hTERT-IFD domain with TPP1 when mutated. Using a similar approach, we find that the IFD domain interacts with the TEN domain but is not essential for intramolecular hTERT interactions with the TEN domain. IFD-TEN interactions are not disrupted by multiple amino acid changes in the IFD or TEN, thus highlighting a complex regulation of IFD-TEN interactions as suggested by recent cryo-EM structures of human telomerase.
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Affiliation(s)
| | - Adrian Young
- Lady Davis Institute for Medical Research, Jewish General Hospital, Montréal, Canada; Department of Anatomy and Cell Biology, McGill University, Montréal, Canada
| | - Chantal Autexier
- Lady Davis Institute for Medical Research, Jewish General Hospital, Montréal, Canada; Department of Anatomy and Cell Biology, McGill University, Montréal, Canada; Department of Medicine, McGill University, Montréal, Canada.
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Garus A, Autexier C. Dyskerin: an essential pseudouridine synthase with multifaceted roles in ribosome biogenesis, splicing, and telomere maintenance. RNA (NEW YORK, N.Y.) 2021; 27:1441-1458. [PMID: 34556550 PMCID: PMC8594475 DOI: 10.1261/rna.078953.121] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Dyskerin and its homologs are ancient and conserved enzymes that catalyze the most common post-transcriptional modification found in cells, pseudouridylation. The resulting pseudouridines provide stability to RNA molecules and regulate ribosome biogenesis and splicing events. Dyskerin does not act independently-it is the core component of a protein heterotetramer, which associates with RNAs that contain the H/ACA motif. The variety of H/ACA RNAs that guide the function of this ribonucleoprotein (RNP) complex highlights the diversity of cellular processes in which dyskerin participates. When associated with small nucleolar (sno) RNAs, it regulates ribosomal (r) RNAs and ribosome biogenesis. By interacting with small Cajal body (sca) RNAs, it targets small nuclear (sn) RNAs to regulate pre-mRNA splicing. As a component of the telomerase holoenzyme, dyskerin binds to the telomerase RNA to modulate telomere maintenance. In a disease context, dyskerin malfunction can result in multiple detrimental phenotypes. Mutations in DKC1, the gene that encodes dyskerin, cause the premature aging syndrome X-linked dyskeratosis congenita (X-DC), a still incurable disorder that typically leads to bone marrow failure. In this review, we present the classical and most recent findings on this essential protein, discussing the evolutionary, structural, and functional aspects of dyskerin and the H/ACA RNP. The latest research underscores the role that dyskerin plays in the regulation of gene expression, translation efficiency, and telomere maintenance, along with the impacts that defective dyskerin has on aging, cell proliferation, haematopoietic potential, and cancer.
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Affiliation(s)
- Alexandre Garus
- Department of Anatomy and Cell Biology, McGill University, Montreal, Quebec, H3A 0C7, Canada
- Jewish General Hospital, Lady Davis Institute, Montreal, Quebec, H3T 1E2, Canada
| | - Chantal Autexier
- Department of Anatomy and Cell Biology, McGill University, Montreal, Quebec, H3A 0C7, Canada
- Jewish General Hospital, Lady Davis Institute, Montreal, Quebec, H3T 1E2, Canada
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10
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Keiten-Schmitz J, Röder L, Hornstein E, Müller-McNicoll M, Müller S. SUMO: Glue or Solvent for Phase-Separated Ribonucleoprotein Complexes and Molecular Condensates? Front Mol Biosci 2021; 8:673038. [PMID: 34026847 PMCID: PMC8138125 DOI: 10.3389/fmolb.2021.673038] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2021] [Accepted: 04/08/2021] [Indexed: 01/01/2023] Open
Abstract
Spatial organization of cellular processes in membranous or membrane-less organelles (MLOs, alias molecular condensates) is a key concept for compartmentalizing biochemical pathways. Prime examples of MLOs are the nucleolus, PML nuclear bodies, nuclear splicing speckles or cytosolic stress granules. They all represent distinct sub-cellular structures typically enriched in intrinsically disordered proteins and/or RNA and are formed in a process driven by liquid-liquid phase separation. Several MLOs are critically involved in proteostasis and their formation, disassembly and composition are highly sensitive to proteotoxic insults. Changes in the dynamics of MLOs are a major driver of cell dysfunction and disease. There is growing evidence that post-translational modifications are critically involved in controlling the dynamics and composition of MLOs and recent evidence supports an important role of the ubiquitin-like SUMO system in regulating both the assembly and disassembly of these structures. Here we will review our current understanding of SUMO function in MLO dynamics under both normal and pathological conditions.
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Affiliation(s)
- Jan Keiten-Schmitz
- Faculty of Medicine, Institute of Biochemistry II, Goethe University, Frankfurt, Germany
| | - Linda Röder
- Faculty of Medicine, Institute of Biochemistry II, Goethe University, Frankfurt, Germany
| | - Eran Hornstein
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel
- Department of Molecular Neuroscience, Weizmann Institute of Science, Rehovot, Israel
| | - Michaela Müller-McNicoll
- Faculty of Biosciences, Institute for Molecular Biosciences, Goethe University, Frankfurt am Main, Germany
| | - Stefan Müller
- Faculty of Medicine, Institute of Biochemistry II, Goethe University, Frankfurt, Germany
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