1
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Nguyen DTM, Koppers M, Farías GG. Endoplasmic reticulum - condensate interactions in protein synthesis and secretion. Curr Opin Cell Biol 2024; 88:102357. [PMID: 38626704 DOI: 10.1016/j.ceb.2024.102357] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2024] [Revised: 03/20/2024] [Accepted: 03/22/2024] [Indexed: 04/18/2024]
Abstract
In the past decade, a growing amount of evidence has demonstrated that organelles do not act autonomously and independently but rather communicate with each other to coordinate different processes for proper cellular function. With a highly extended network throughout the cell, the endoplasmic reticulum (ER) plays a central role in interorganelle communication through membrane contact sites. Here, we highlight recent evidence indicating that the ER also forms contacts with membrane-less organelles. These interactions contribute to the dynamic assembly and disassembly of condensates and controlled protein secretion. Additionally, emerging evidence suggests their involvement in mRNA localization and localized translation. We further explore exciting future directions of this emerging theme in the organelle contact site field.
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Affiliation(s)
- Dan T M Nguyen
- Cell Biology, Neurobiology and Biophysics, Department of Biology, Faculty of Science, Utrecht University, Utrecht, The Netherlands
| | - Max Koppers
- Department of Functional Genomics, Center for Neurogenomics and Cognitive Research, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands.
| | - Ginny G Farías
- Cell Biology, Neurobiology and Biophysics, Department of Biology, Faculty of Science, Utrecht University, Utrecht, The Netherlands.
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2
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Boone M, Zappa F. Signaling plasticity in the integrated stress response. Front Cell Dev Biol 2023; 11:1271141. [PMID: 38143923 PMCID: PMC10740175 DOI: 10.3389/fcell.2023.1271141] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2023] [Accepted: 11/29/2023] [Indexed: 12/26/2023] Open
Abstract
The Integrated Stress Response (ISR) is an essential homeostatic signaling network that controls the cell's biosynthetic capacity. Four ISR sensor kinases detect multiple stressors and relay this information to downstream effectors by phosphorylating a common node: the alpha subunit of the eukaryotic initiation factor eIF2. As a result, general protein synthesis is repressed while select transcripts are preferentially translated, thus remodeling the proteome and transcriptome. Mounting evidence supports a view of the ISR as a dynamic signaling network with multiple modulators and feedback regulatory features that vary across cell and tissue types. Here, we discuss updated views on ISR sensor kinase mechanisms, how the subcellular localization of ISR components impacts signaling, and highlight ISR signaling differences across cells and tissues. Finally, we consider crosstalk between the ISR and other signaling pathways as a determinant of cell health.
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3
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Redding A, Grabocka E. Stress granules and hormetic adaptation of cancer. Trends Cancer 2023; 9:995-1005. [PMID: 37704502 PMCID: PMC10843007 DOI: 10.1016/j.trecan.2023.08.005] [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: 04/04/2023] [Revised: 08/08/2023] [Accepted: 08/14/2023] [Indexed: 09/15/2023]
Abstract
Cell stress is inherent to cancer and a key driver of tumorigenesis. Recent studies have proposed that cell stress promotes tumorigenesis through non-membranous organelles known as stress granules (SGs). While the biology of SGs is an emerging field, all studies to date point to the enhanced ability of cancer cells to form SGs compared with normal cells, a heightened dependence on SGs for survival under adverse conditions and for chemotherapy resistance, and the dependence of tumors on SGs for growth. Why cancer cells become dependent on SGs and how SGs promote tumorigenesis remain to be elucidated. Here, we attempt to provide a framework for answering these questions by framing SGs as a hormetic response to tumor-associated stress stimuli.
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Affiliation(s)
- Alexandra Redding
- Department of Pharmacology, Physiology, and Cancer Biology, Sidney Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, PA, 19107, USA
| | - Elda Grabocka
- Department of Pharmacology, Physiology, and Cancer Biology, Sidney Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, PA, 19107, USA.
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4
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Hu S, Zhang Y, Yi Q, Yang C, Liu Y, Bai Y. Time-resolved proteomic profiling reveals compositional and functional transitions across the stress granule life cycle. Nat Commun 2023; 14:7782. [PMID: 38012130 PMCID: PMC10682001 DOI: 10.1038/s41467-023-43470-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2022] [Accepted: 11/09/2023] [Indexed: 11/29/2023] Open
Abstract
Stress granules (SGs) are dynamic, membrane-less organelles. With their formation and disassembly processes characterized, it remains elusive how compositional transitions are coordinated during prolonged stress to meet changing functional needs. Here, using time-resolved proteomic profiling of the acute to prolonged heat-shock SG life cycle, we identify dynamic SG proteins, further segregated into early and late proteins. Comparison of different groups of SG proteins suggests that their biochemical properties help coordinate SG compositional and functional transitions. In particular, early proteins, with high phase-separation-propensity, drive the rapid formation of the initial SG platform, while late proteins are subsequently recruited as discrete modules to further functionalize SGs. This model, supported by immunoblotting and immunofluorescence imaging, provides a conceptual framework for the compositional transitions throughout the acute to prolonged SG life cycle. Additionally, an early SG constituent, non-muscle myosin II, is shown to promote SG formation by increasing SG fusion, underscoring the strength of this dataset in revealing the complexity of SG regulation.
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Affiliation(s)
- Shuyao Hu
- School of Life Science and Technology, ShanghaiTech University, 201210, Shanghai, China.
| | - Yufeng Zhang
- School of Life Science and Technology, ShanghaiTech University, 201210, Shanghai, China
| | - Qianqian Yi
- School of Life Science and Technology, ShanghaiTech University, 201210, Shanghai, China
| | - Cuiwei Yang
- School of Life Science and Technology, ShanghaiTech University, 201210, Shanghai, China
| | - Yanfen Liu
- School of Life Science and Technology, ShanghaiTech University, 201210, Shanghai, China.
| | - Yun Bai
- School of Life Science and Technology, ShanghaiTech University, 201210, Shanghai, China.
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5
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Liu C, Zhou L, Chen J, Yang Z, Chen S, Wang X, Liu X, Li Y, Zhang C, Wang Y, Chen Y, Li H, Shen C, Sun H. Galectin-7 promotes cisplatin efficacy by facilitating apoptosis and G3BP1 degradation in cervical cancer. Biochem Pharmacol 2023; 217:115834. [PMID: 37778447 DOI: 10.1016/j.bcp.2023.115834] [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: 05/30/2023] [Revised: 09/23/2023] [Accepted: 09/26/2023] [Indexed: 10/03/2023]
Abstract
The emergence of chemoresistance in cervical cancer is extremely challenging in chemotherapy. Oxidative stress has emerged as the regulatory factor in drug resistance, but the detailed mechanism is still unknown. Stress granules, are membrane-less ribonucleoprotein-based condensates, could enhance chemoresistance by sequestering proapoptotic proteins inhibition of cell death upon exposure to drug-induced oxidative stress. Galectin-7, a member of galectin family, exerts varied roles in tumor repression or progression in different cancers. However, its role in cervical cancer has not been sufficiently studied. Here, we found that galectin-7 promotes cisplatin (CDDP) induced apoptosis and associates with stress granule-nucleating protein G3BP1 degradation. With the treatment of cisplatin, galectin-7 could enhance apoptosis by upregulating cleaved-PARP1 and the generation of reactive oxygen species (ROS), promoting mitochondrial fission, and reducing mitochondrial membrane potential (MMP). Furthermore, galectin-7 also reduces resistance by facilitating cisplatin-induced stress granules clearance through galectin-7/RACK1/G3BP1 axis. All these data suggested that galectin-7 promotes cisplatin sensitivity, and it would be potential target for potentiating efficacy in cervical cancer chemotherapy.
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Affiliation(s)
- Chenglong Liu
- College of Life Sciences, Wuhan University, Wuhan 430072, China
| | - Limin Zhou
- Department of Gynecology, Maternal and Child Health Hospital of Hubei Province, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430070, China
| | - Jia Chen
- College of Life Sciences, Wuhan University, Wuhan 430072, China
| | - Zelan Yang
- College of Life Sciences, Wuhan University, Wuhan 430072, China
| | - Shan Chen
- School of Medicine, Wuhan University of Science and Technology, Wuhan 430065, China
| | - Xueqing Wang
- College of Life Sciences, Wuhan University, Wuhan 430072, China
| | - Xiaomei Liu
- College of Life Sciences, Wuhan University, Wuhan 430072, China
| | - Yang Li
- College of Life Sciences, Wuhan University, Wuhan 430072, China
| | - Can Zhang
- College of Life Sciences, Wuhan University, Wuhan 430072, China
| | - Yirong Wang
- College of Life Sciences, Wuhan University, Wuhan 430072, China
| | - Yihao Chen
- College of Life Sciences, Wuhan University, Wuhan 430072, China
| | - Huan Li
- College of Life Sciences, Wuhan University, Wuhan 430072, China
| | - Chao Shen
- College of Life Sciences, Wuhan University, Wuhan 430072, China
| | - Hui Sun
- College of Life Sciences, Wuhan University, Wuhan 430072, China; Hubei Province Key Laboratory of Allergy and Immunology, Wuhan University, Wuhan 430071, China.
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6
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Kim N, Kim TH, Kim C, Lee JE, Kang MG, Shin S, Jung M, Kim JS, Mun JY, Rhee HW, Park SY, Shin Y, Yoo JY. Intrinsically disordered region-mediated condensation of IFN-inducible SCOTIN/SHISA-5 inhibits ER-to-Golgi vesicle transport. Dev Cell 2023; 58:1950-1966.e8. [PMID: 37816329 DOI: 10.1016/j.devcel.2023.08.030] [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: 12/14/2022] [Revised: 07/27/2023] [Accepted: 08/25/2023] [Indexed: 10/12/2023]
Abstract
Newly synthesized proteins in the endoplasmic reticulum (ER) are sorted by coat protein complex II (COPII) at the ER exit site en route to the Golgi. Under cellular stresses, COPII proteins become targets of regulation to control the transport. Here, we show that the COPII outer coat proteins Sec31 and Sec13 are selectively sequestered into the biomolecular condensate of SCOTIN/SHISA-5, which interferes with COPII vesicle formation and inhibits ER-to-Golgi transport. SCOTIN is an ER transmembrane protein with a cytosolic intrinsically disordered region (IDR), which is required and essential for the formation of condensates. Upon IFN-γ stimulation, which is a cellular condition that induces SCOTIN expression and condensation, ER-to-Golgi transport was inhibited in a SCOTIN-dependent manner. Furthermore, cancer-associated mutations of SCOTIN perturb its ability to form condensates and control transport. Together, we propose that SCOTIN impedes the ER-to-Golgi transport through its ability to form biomolecular condensates at the ER membrane.
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Affiliation(s)
- Nari Kim
- Department of Life Sciences, Pohang University of Science and Technology, Pohang 37673, Republic of Korea.
| | - Tae-Hyeon Kim
- Department of Life Sciences, Pohang University of Science and Technology, Pohang 37673, Republic of Korea
| | - Chaelim Kim
- Interdisciplinary Program in Bioengineering, Seoul National University, Seoul 08826, Republic of Korea
| | - Jee-Eun Lee
- Department of Life Sciences, Pohang University of Science and Technology, Pohang 37673, Republic of Korea
| | - Myeong-Gyun Kang
- Department of Chemistry, Seoul National University, Seoul 08826, Republic of Korea
| | - Sanghee Shin
- School of Biological Sciences, Seoul National University, Seoul 08826, Republic of Korea; Center for RNA Research, Institute for Basic Science (IBS), Seoul 08826, Republic of Korea
| | - Minkyo Jung
- Neural Circuit Research Group, Korea Brain Research Institute, Daegu 41062, Republic of Korea
| | - Jong-Seo Kim
- School of Biological Sciences, Seoul National University, Seoul 08826, Republic of Korea; Center for RNA Research, Institute for Basic Science (IBS), Seoul 08826, Republic of Korea
| | - Ji Young Mun
- Neural Circuit Research Group, Korea Brain Research Institute, Daegu 41062, Republic of Korea
| | - Hyun-Woo Rhee
- Department of Chemistry, Seoul National University, Seoul 08826, Republic of Korea; School of Biological Sciences, Seoul National University, Seoul 08826, Republic of Korea
| | - Seung-Yeol Park
- Department of Life Sciences, Pohang University of Science and Technology, Pohang 37673, Republic of Korea
| | - Yongdae Shin
- Interdisciplinary Program in Bioengineering, Seoul National University, Seoul 08826, Republic of Korea; Department of Mechanical Engineering, Seoul National University, Seoul 08826, Republic of Korea
| | - Joo-Yeon Yoo
- Department of Life Sciences, Pohang University of Science and Technology, Pohang 37673, Republic of Korea.
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7
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Gallo R, Rai AK, McIntyre ABR, Meyer K, Pelkmans L. DYRK3 enables secretory trafficking by maintaining the liquid-like state of ER exit sites. Dev Cell 2023; 58:1880-1897.e11. [PMID: 37643612 DOI: 10.1016/j.devcel.2023.08.005] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2022] [Revised: 02/16/2023] [Accepted: 08/01/2023] [Indexed: 08/31/2023]
Abstract
The dual-specificity kinase DYRK3 controls the formation and dissolution of multiple biomolecular condensates, regulating processes including stress recovery and mitotic progression. Here, we report that DYRK3 functionally interacts with proteins associated with endoplasmic reticulum (ER) exit sites (ERESs) and that inhibition of DYRK3 perturbs the organization of the ERES-Golgi interface and secretory trafficking. DYRK3-mediated regulation of ERES depends on the N-terminal intrinsically disordered region (IDR) of the peripheral membrane protein SEC16A, which co-phase separates with ERES components to form liquid-like condensates on the surface of the ER. By modulating the liquid-like properties of ERES, we show that their physical state is essential for functional cargo trafficking through the early secretory pathway. Our findings support a mechanism whereby phosphorylation by DYRK3 and its reversal by serine-threonine phosphatases regulate the material properties of ERES to create a favorable physicochemical environment for directional membrane traffic in eukaryotic cells.
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Affiliation(s)
- Raffaella Gallo
- Department of Molecular Life Sciences, University of Zurich, 8046 Zurich, Switzerland
| | - Arpan Kumar Rai
- Department of Molecular Life Sciences, University of Zurich, 8046 Zurich, Switzerland.
| | - Alexa B R McIntyre
- Department of Molecular Life Sciences, University of Zurich, 8046 Zurich, Switzerland
| | - Katrina Meyer
- Department of Molecular Life Sciences, University of Zurich, 8046 Zurich, Switzerland
| | - Lucas Pelkmans
- Department of Molecular Life Sciences, University of Zurich, 8046 Zurich, Switzerland.
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8
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Chukrallah LG, Snyder EM. Modern tools applied to classic structures: Approaches for mammalian male germ cell RNA granule research. Andrology 2023; 11:872-883. [PMID: 36273399 DOI: 10.1111/andr.13320] [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: 07/29/2022] [Revised: 09/20/2022] [Accepted: 10/10/2022] [Indexed: 11/28/2022]
Abstract
First reported in the 1800s, germ cell granules are small nonmembrane bound RNA-rich regions of the cytoplasm. These sites of critical RNA processing and storage in the male germ cell are essential for proper differentiation and development and are present in a wide range of species from Caenorhabditis elegans through mammals. Initially characterized by light and electron microscopy, more modern techniques such as immunofluorescence and genetic models have played a major role in expanding our understanding of the composition of these structures. While these methods have given light to potential granule functions, much work remains to be done. The current expansion of imaging technologies and omics-scale analyses to germ cell granule research will drive the field forward considerably. Many of these methods, both current and upcoming, have considerable caveats and limitations that necessitate a holistic approach to the study of germ granules. By combining and balancing different techniques, the field is poised to elucidate the nature of these critical structures.
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Affiliation(s)
- Lauren G Chukrallah
- Department of Animal Science, Rutgers, the State University of New Jersey, New Brunswick, New Jersey, USA
| | - Elizabeth M Snyder
- Department of Animal Science, Rutgers, the State University of New Jersey, New Brunswick, New Jersey, USA
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9
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Millar SR, Huang JQ, Schreiber KJ, Tsai YC, Won J, Zhang J, Moses AM, Youn JY. A New Phase of Networking: The Molecular Composition and Regulatory Dynamics of Mammalian Stress Granules. Chem Rev 2023. [PMID: 36662637 PMCID: PMC10375481 DOI: 10.1021/acs.chemrev.2c00608] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Stress granules (SGs) are cytosolic biomolecular condensates that form in response to cellular stress. Weak, multivalent interactions between their protein and RNA constituents drive their rapid, dynamic assembly through phase separation coupled to percolation. Though a consensus model of SG function has yet to be determined, their perceived implication in cytoprotective processes (e.g., antiviral responses and inhibition of apoptosis) and possible role in the pathogenesis of various neurodegenerative diseases (e.g., amyotrophic lateral sclerosis and frontotemporal dementia) have drawn great interest. Consequently, new studies using numerous cell biological, genetic, and proteomic methods have been performed to unravel the mechanisms underlying SG formation, organization, and function and, with them, a more clearly defined SG proteome. Here, we provide a consensus SG proteome through literature curation and an update of the user-friendly database RNAgranuleDB to version 2.0 (http://rnagranuledb.lunenfeld.ca/). With this updated SG proteome, we use next-generation phase separation prediction tools to assess the predisposition of SG proteins for phase separation and aggregation. Next, we analyze the primary sequence features of intrinsically disordered regions (IDRs) within SG-resident proteins. Finally, we review the protein- and RNA-level determinants, including post-translational modifications (PTMs), that regulate SG composition and assembly/disassembly dynamics.
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Affiliation(s)
- Sean R Millar
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario M5S 1A8, Canada
| | - Jie Qi Huang
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario M5S 1A8, Canada
| | - Karl J Schreiber
- Program in Molecular Medicine, The Hospital for Sick Children, Toronto, Ontario M5G 0A4, Canada
| | - Yi-Cheng Tsai
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario M5S 1A8, Canada
| | - Jiyun Won
- Department of Cell & Systems Biology, University of Toronto, Toronto, Ontario M5S 3B2, Canada
| | - Jianping Zhang
- Lunenfeld-Tanenbaum Research Institute, Sinai Health System, Toronto, Ontario M5G 1X5, Canada
| | - Alan M Moses
- Department of Cell & Systems Biology, University of Toronto, Toronto, Ontario M5S 3B2, Canada.,Department of Computer Science, University of Toronto, Toronto, Ontario M5T 3A1, Canada.,The Centre for the Analysis of Genome Evolution and Function, University of Toronto, Toronto, Ontario M5S 3B2, Canada
| | - Ji-Young Youn
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario M5S 1A8, Canada.,Program in Molecular Medicine, The Hospital for Sick Children, Toronto, Ontario M5G 0A4, Canada
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10
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Bilkei‐Gorzo O, Heunis T, Marín‐Rubio JL, Cianfanelli FR, Raymond BBA, Inns J, Fabrikova D, Peltier J, Oakley F, Schmid R, Härtlova A, Trost M. The E3 ubiquitin ligase RNF115 regulates phagosome maturation and host response to bacterial infection. EMBO J 2022; 41:e108970. [PMID: 36281581 PMCID: PMC9713710 DOI: 10.15252/embj.2021108970] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2021] [Revised: 10/01/2022] [Accepted: 10/06/2022] [Indexed: 01/15/2023] Open
Abstract
Phagocytosis is a key process in innate immunity and homeostasis. After particle uptake, newly formed phagosomes mature by acquisition of endolysosomal enzymes. Macrophage activation by interferon gamma (IFN-γ) increases microbicidal activity, but delays phagosomal maturation by an unknown mechanism. Using quantitative proteomics, we show that phagosomal proteins harbour high levels of typical and atypical ubiquitin chain types. Moreover, phagosomal ubiquitylation of vesicle trafficking proteins is substantially enhanced upon IFN-γ activation of macrophages, suggesting a role in regulating phagosomal functions. We identified the E3 ubiquitin ligase RNF115, which is enriched on phagosomes of IFN-γ activated macrophages, as an important regulator of phagosomal maturation. Loss of RNF115 protein or ligase activity enhanced phagosomal maturation and increased cytokine responses to bacterial infection, suggesting that both innate immune signalling from the phagosome and phagolysosomal trafficking are controlled through ubiquitylation. RNF115 knock-out mice show less tissue damage in response to S. aureus infection, indicating a role of RNF115 in inflammatory responses in vivo. In conclusion, RNF115 and phagosomal ubiquitylation are important regulators of innate immune functions during bacterial infections.
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Affiliation(s)
- Orsolya Bilkei‐Gorzo
- Wallenberg Centre for Molecular and Translational Medicine, Department of Microbiology and Immunology at Institute of BiomedicineUniversity of GothenburgGothenburgSweden,MRC Protein Phosphorylation and Ubiquitylation UnitUniversity of DundeeDundeeUK
| | - Tiaan Heunis
- Biosciences InstituteNewcastle UniversityNewcastle upon TyneUK
| | | | | | | | - Joseph Inns
- Biosciences InstituteNewcastle UniversityNewcastle upon TyneUK
| | - Daniela Fabrikova
- Wallenberg Centre for Molecular and Translational Medicine, Department of Microbiology and Immunology at Institute of BiomedicineUniversity of GothenburgGothenburgSweden
| | - Julien Peltier
- MRC Protein Phosphorylation and Ubiquitylation UnitUniversity of DundeeDundeeUK,Biosciences InstituteNewcastle UniversityNewcastle upon TyneUK
| | - Fiona Oakley
- Biosciences InstituteNewcastle UniversityNewcastle upon TyneUK,Newcastle Fibrosis Research GroupNewcastle UniversityNewcastle upon TyneUK
| | - Ralf Schmid
- Leicester Institute of Structural and Chemical BiologyUniversity of LeicesterLeicesterUK,Department of Molecular and Cell BiologyUniversity of LeicesterLeicesterUK
| | - Anetta Härtlova
- Wallenberg Centre for Molecular and Translational Medicine, Department of Microbiology and Immunology at Institute of BiomedicineUniversity of GothenburgGothenburgSweden,MRC Protein Phosphorylation and Ubiquitylation UnitUniversity of DundeeDundeeUK,Biosciences InstituteNewcastle UniversityNewcastle upon TyneUK
| | - Matthias Trost
- MRC Protein Phosphorylation and Ubiquitylation UnitUniversity of DundeeDundeeUK,Biosciences InstituteNewcastle UniversityNewcastle upon TyneUK
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11
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Zappa F, Muniozguren NL, Wilson MZ, Costello MS, Ponce-Rojas JC, Acosta-Alvear D. Signaling by the integrated stress response kinase PKR is fine-tuned by dynamic clustering. J Cell Biol 2022; 221:213199. [PMID: 35522180 PMCID: PMC9086502 DOI: 10.1083/jcb.202111100] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2021] [Revised: 02/15/2022] [Accepted: 04/05/2022] [Indexed: 12/16/2022] Open
Abstract
The double-stranded RNA sensor kinase PKR is one of four integrated stress response (ISR) sensor kinases that phosphorylate the α subunit of eukaryotic initiation factor 2 (eIF2α) in response to stress. The current model of PKR activation considers the formation of back-to-back PKR dimers as a prerequisite for signal propagation. Here we show that PKR signaling involves the assembly of dynamic PKR clusters. PKR clustering is driven by ligand binding to PKR’s sensor domain and by front-to-front interfaces between PKR’s kinase domains. PKR clusters are discrete, heterogeneous, autonomous coalescences that share some protein components with processing bodies. Strikingly, eIF2α is not recruited to PKR clusters, and PKR cluster disruption enhances eIF2α phosphorylation. Together, these results support a model in which PKR clustering may limit encounters between PKR and eIF2α to buffer downstream signaling and prevent the ISR from misfiring.
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Affiliation(s)
- Francesca Zappa
- Department of Molecular, Cellular and Developmental Biology, University of California, Santa Barbara, Santa Barbara, CA
| | - Nerea L Muniozguren
- Department of Molecular, Cellular and Developmental Biology, University of California, Santa Barbara, Santa Barbara, CA
| | - Maxwell Z Wilson
- Department of Molecular, Cellular and Developmental Biology, University of California, Santa Barbara, Santa Barbara, CA
| | - Michael S Costello
- Department of Molecular, Cellular and Developmental Biology, University of California, Santa Barbara, Santa Barbara, CA
| | - Jose Carlos Ponce-Rojas
- Department of Molecular, Cellular and Developmental Biology, University of California, Santa Barbara, Santa Barbara, CA
| | - Diego Acosta-Alvear
- Department of Molecular, Cellular and Developmental Biology, University of California, Santa Barbara, Santa Barbara, CA
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12
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Yao J, Tu Y, Shen C, Zhou Q, Xiao H, Jia D, Sun Q. Nuclear import receptors and hnRNPK mediates nuclear import and stress granule localization of SIRLOIN. Cell Mol Life Sci 2021; 78:7617-7633. [PMID: 34689235 PMCID: PMC11073023 DOI: 10.1007/s00018-021-03992-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2021] [Revised: 10/08/2021] [Accepted: 10/11/2021] [Indexed: 02/08/2023]
Abstract
The majority of lncRNAs and a small fraction of mRNAs localize in the cell nucleus to exert their functions. A SIRLOIN RNA motif was previously reported to drive its nuclear localization by the RNA-binding protein hnRNPK. However, the underlying mechanism remains unclear. Here, we report crystal structures of hnRNPK in complex with SIRLOIN, and with the nuclear import receptor (NIR) Impα1, respectively. The protein hnRNPK bound to SIRLOIN with multiple weak interactions, and interacted Impα1 using an independent high-affinity site. Forming a complex with hnRNPK and Impα1 was essential for the nuclear import and stress granule localization of SIRLOIN in semi-permeabilized cells. Nuclear import of SIRLOIN enhanced with increasing NIR concentrations, but its stress granule localization peaked at a low NIR concentration. Collectively, we propose a mechanism of SIRLOIN localization, in which NIRs functioned as drivers/regulators, and hnRNPK as an adaptor.
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Affiliation(s)
- Jialin Yao
- Department of Pathology, State Key Laboratory of Biotherapy and Cancer Centre, West China Hospital, Sichuan University, and Collaborative Innovation Centre of Biotherapy, Chengdu, 610041, China
| | - Yingfeng Tu
- Division of Neurology, Department of Pediatrics, Key Laboratory of Birth Defects and Related Diseases of Women and Children, West China Second University Hospital, Sichuan University, Chengdu, 610041, China
| | - Congcong Shen
- Department of Pathology, State Key Laboratory of Biotherapy and Cancer Centre, West China Hospital, Sichuan University, and Collaborative Innovation Centre of Biotherapy, Chengdu, 610041, China
| | - Qiao Zhou
- Department of Pathology, State Key Laboratory of Biotherapy and Cancer Centre, West China Hospital, Sichuan University, and Collaborative Innovation Centre of Biotherapy, Chengdu, 610041, China
| | - Hengyi Xiao
- Aging Research Lab, National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, and Collaborative Innovation Centre of Biotherapy, Chengdu, 610041, China
| | - Da Jia
- Division of Neurology, Department of Pediatrics, Key Laboratory of Birth Defects and Related Diseases of Women and Children, West China Second University Hospital, Sichuan University, Chengdu, 610041, China
| | - Qingxiang Sun
- Department of Pathology, State Key Laboratory of Biotherapy and Cancer Centre, West China Hospital, Sichuan University, and Collaborative Innovation Centre of Biotherapy, Chengdu, 610041, China.
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13
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Faoro C, Ataide SF. Noncanonical Functions and Cellular Dynamics of the Mammalian Signal Recognition Particle Components. Front Mol Biosci 2021; 8:679584. [PMID: 34113652 PMCID: PMC8185352 DOI: 10.3389/fmolb.2021.679584] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2021] [Accepted: 04/29/2021] [Indexed: 12/24/2022] Open
Abstract
The signal recognition particle (SRP) is a ribonucleoprotein complex fundamental for co-translational delivery of proteins to their proper membrane localization and secretory pathways. Literature of the past two decades has suggested new roles for individual SRP components, 7SL RNA and proteins SRP9, SRP14, SRP19, SRP54, SRP68 and SRP72, outside the SRP cycle. These noncanonical functions interconnect SRP with a multitude of cellular and molecular pathways, including virus-host interactions, stress response, transcriptional regulation and modulation of apoptosis in autoimmune diseases. Uncovered novel properties of the SRP components present a new perspective for the mammalian SRP as a biological modulator of multiple cellular processes. As a consequence of these findings, SRP components have been correlated with a growing list of diseases, such as cancer progression, myopathies and bone marrow genetic diseases, suggesting a potential for development of SRP-target therapies of each individual component. For the first time, here we present the current knowledge on the SRP noncanonical functions and raise the need of a deeper understanding of the molecular interactions between SRP and accessory cellular components. We examine diseases associated with SRP components and discuss the development and feasibility of therapeutics targeting individual SRP noncanonical functions.
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Affiliation(s)
- Camilla Faoro
- School of Life and Environmental Sciences, The University of Sydney, Sydney, NSW, Australia
| | - Sandro F Ataide
- School of Life and Environmental Sciences, The University of Sydney, Sydney, NSW, Australia
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Cavin1 intrinsically disordered domains are essential for fuzzy electrostatic interactions and caveola formation. Nat Commun 2021; 12:931. [PMID: 33568658 PMCID: PMC7875971 DOI: 10.1038/s41467-021-21035-4] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2020] [Accepted: 01/06/2021] [Indexed: 01/30/2023] Open
Abstract
Caveolae are spherically shaped nanodomains of the plasma membrane, generated by cooperative assembly of caveolin and cavin proteins. Cavins are cytosolic peripheral membrane proteins with negatively charged intrinsically disordered regions that flank positively charged α-helical regions. Here, we show that the three disordered domains of Cavin1 are essential for caveola formation and dynamic trafficking of caveolae. Electrostatic interactions between disordered regions and α-helical regions promote liquid-liquid phase separation behaviour of Cavin1 in vitro, assembly of Cavin1 oligomers in solution, generation of membrane curvature, association with caveolin-1, and Cavin1 recruitment to caveolae in cells. Removal of the first disordered region causes irreversible gel formation in vitro and results in aberrant caveola trafficking through the endosomal system. We propose a model for caveola assembly whereby fuzzy electrostatic interactions between Cavin1 and caveolin-1 proteins, combined with membrane lipid interactions, are required to generate membrane curvature and a metastable caveola coat.
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15
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Bodnar B, DeGruttola A, Zhu Y, Lin Y, Zhang Y, Mo X, Hu W. Emerging role of NIK/IKK2-binding protein (NIBP)/trafficking protein particle complex 9 (TRAPPC9) in nervous system diseases. Transl Res 2020; 224:55-70. [PMID: 32434006 PMCID: PMC7442628 DOI: 10.1016/j.trsl.2020.05.001] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/16/2019] [Revised: 05/02/2020] [Accepted: 05/05/2020] [Indexed: 02/05/2023]
Abstract
NFκB signaling and protein trafficking network play important roles in various biological and pathological processes. NIK-and-IKK2-binding protein (NIBP), also known as trafficking protein particle complex 9 (TRAPPC9), is a prototype member of a novel protein family, and has been shown to regulate both NFκB signaling pathway and protein transport/trafficking. NIBP is extensively expressed in the nervous system and plays an important role in regulating neurogenesis and neuronal differentiation. NIBP/TRAPPC9 mutations have been linked to an autosomal recessive intellectual disability syndrome, called NIBP Syndrome, which is characterized by nonsyndromic autosomal recessive intellectual disability along with other symptoms such as obesity, microcephaly, and facial dysmorphia. As more cases of NIBP Syndrome are identified, new light is being shed on the role of NIBP/TRAPPC9 in the central nervous system developments and diseases. NIBP is also involved in the enteric nervous system. This review will highlight the importance of NIBP/TRAPPC9 in central and enteric nervous system diseases, and the established possible mechanisms for developing a potential therapeutic.
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Affiliation(s)
- Brittany Bodnar
- Center for Metabolic Disease Research, Temple University Lewis Katz School of Medicine, Philadelphia, Pennsylvania; MD/PhD and Biomedical Sciences Graduate Program, Temple University Lewis Katz School of Medicine, Philadelphia, Pennsylvania
| | - Arianna DeGruttola
- Center for Metabolic Disease Research, Temple University Lewis Katz School of Medicine, Philadelphia, Pennsylvania; MD/PhD and Biomedical Sciences Graduate Program, Temple University Lewis Katz School of Medicine, Philadelphia, Pennsylvania
| | - Yuanjun Zhu
- Center for Metabolic Disease Research, Temple University Lewis Katz School of Medicine, Philadelphia, Pennsylvania; Department of Pathology and Laboratory Medicine, Temple University Lewis Katz School of Medicine, Philadelphia, Pennsylvania; Department of Molecular and Cellular Pharmacology, Peking University School of Pharmaceutical Sciences, Beijing, China
| | - Yuan Lin
- Center for Metabolic Disease Research, Temple University Lewis Katz School of Medicine, Philadelphia, Pennsylvania; Department of Pathology and Laboratory Medicine, Temple University Lewis Katz School of Medicine, Philadelphia, Pennsylvania
| | - Yonggang Zhang
- Center for Stem Cell Research and Application, Institute of Blood Transfusion, Chinese Academy of Medical Sciences & Peking Union Medical College (CAMS & PUMC), Chengdu, China
| | - Xianming Mo
- Laboratory of Stem Cell Biology, State Key Laboratory of Biotherapy, West China Hospital, West China Medical School, Sichuan University, Chengdu, China
| | - Wenhui Hu
- Center for Metabolic Disease Research, Temple University Lewis Katz School of Medicine, Philadelphia, Pennsylvania; MD/PhD and Biomedical Sciences Graduate Program, Temple University Lewis Katz School of Medicine, Philadelphia, Pennsylvania; Department of Pathology and Laboratory Medicine, Temple University Lewis Katz School of Medicine, Philadelphia, Pennsylvania.
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