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Chen W, Motsinger MM, Li J, Bohannon KP, Hanson PI. Ca 2+-sensor ALG-2 engages ESCRTs to enhance lysosomal membrane resilience to osmotic stress. Proc Natl Acad Sci U S A 2024; 121:e2318412121. [PMID: 38781205 PMCID: PMC11145288 DOI: 10.1073/pnas.2318412121] [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: 10/24/2023] [Accepted: 04/10/2024] [Indexed: 05/25/2024] Open
Abstract
Lysosomes are central players in cellular catabolism, signaling, and metabolic regulation. Cellular and environmental stresses that damage lysosomal membranes can compromise their function and release toxic content into the cytoplasm. Here, we examine how cells respond to osmotic stress within lysosomes. Using sensitive assays of lysosomal leakage and rupture, we examine acute effects of the osmotic disruptant glycyl-L-phenylalanine 2-naphthylamide (GPN). Our findings reveal that low concentrations of GPN rupture a small fraction of lysosomes, but surprisingly trigger Ca2+ release from nearly all. Chelating cytoplasmic Ca2+ makes lysosomes more sensitive to GPN-induced rupture, suggesting a role for Ca2+ in lysosomal membrane resilience. GPN-elicited Ca2+ release causes the Ca2+-sensor Apoptosis Linked Gene-2 (ALG-2), along with Endosomal Sorting Complex Required for Transport (ESCRT) proteins it interacts with, to redistribute onto lysosomes. Functionally, ALG-2, but not its ESCRT binding-disabled ΔGF122 splice variant, increases lysosomal resilience to osmotic stress. Importantly, elevating juxta-lysosomal Ca2+ without membrane damage by activating TRPML1 also recruits ALG-2 and ESCRTs, protecting lysosomes from subsequent osmotic rupture. These findings reveal that Ca2+, through ALG-2, helps bring ESCRTs to lysosomes to enhance their resilience and maintain organelle integrity in the face of osmotic stress.
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Affiliation(s)
- Wei Chen
- Department of Biological Chemistry, University of Michigan School of Medicine, Ann Arbor, MI48109
| | - Madeline M. Motsinger
- Department of Biological Chemistry, University of Michigan School of Medicine, Ann Arbor, MI48109
| | - Jiaqian Li
- Department of Biological Chemistry, University of Michigan School of Medicine, Ann Arbor, MI48109
- Department of Cell and Developmental Biology, University of Michigan School of Medicine, Ann Arbor, MI48109
| | - Kevin P. Bohannon
- Department of Biological Chemistry, University of Michigan School of Medicine, Ann Arbor, MI48109
| | - Phyllis I. Hanson
- Department of Biological Chemistry, University of Michigan School of Medicine, Ann Arbor, MI48109
- Department of Cell and Developmental Biology, University of Michigan School of Medicine, Ann Arbor, MI48109
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2
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Zhu Y, Li Q. Multifaceted roles of PDCD6 both within and outside the cell. J Cell Physiol 2024; 239:e31235. [PMID: 38436472 DOI: 10.1002/jcp.31235] [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: 12/22/2023] [Revised: 02/15/2024] [Accepted: 02/20/2024] [Indexed: 03/05/2024]
Abstract
Programmed cell death protein 6 (PDCD6) is an evolutionarily conserved Ca2+-binding protein. PDCD6 is involved in regulating multifaceted and pleiotropic cellular processes in different cellular compartments. For instance, nuclear PDCD6 regulates apoptosis and alternative splicing. PDCD6 is required for coat protein complex II-dependent endoplasmic reticulum-to-Golgi apparatus vesicular transport in the cytoplasm. Recent advances suggest that cytoplasmic PDCD6 is involved in the regulation of cytoskeletal dynamics and innate immune responses. Additionally, membranous PDCD6 participates in membrane repair through endosomal sorting complex required for transport complex-dependent membrane budding. Interestingly, extracellular vesicles are rich in PDCD6. Moreover, abnormal expression of PDCD6 is closely associated with many diseases, especially cancer. PDCD6 is therefore a multifaceted but pivotal protein in vivo. To gain a more comprehensive understanding of PDCD6 functions and to focus and stimulate PDCD6 research, this review summarizes key developments in its role in different subcellular compartments, processes, and pathologies.
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Affiliation(s)
- Yigao Zhu
- Center for Cell Structure and Function, Shandong Provincial Key Laboratory of Animal Resistance Biology, Collaborative Innovation Center of Cell Biology in Universities of Shandong, College of Life Sciences, Shandong Normal University, Jinan, China
| | - Qingchao Li
- Center for Cell Structure and Function, Shandong Provincial Key Laboratory of Animal Resistance Biology, Collaborative Innovation Center of Cell Biology in Universities of Shandong, College of Life Sciences, Shandong Normal University, Jinan, China
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Chen W, Motsinger MM, Li J, Bohannon KP, Hanson PI. Ca 2+ -sensor ALG-2 engages ESCRTs to enhance lysosomal membrane resilience to osmotic stress. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.02.04.578682. [PMID: 38352356 PMCID: PMC10862787 DOI: 10.1101/2024.02.04.578682] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2024]
Abstract
Lysosomes are central players in cellular catabolism, signaling, and metabolic regulation. Cellular and environmental stresses that damage lysosomal membranes can compromise their function and release toxic content into the cytoplasm. Here, we examine how cells respond to osmotic stress within lysosomes. Using sensitive assays of lysosomal leakage and rupture, we examine acute effects of the cathepsin C-metabolized osmotic disruptant glycyl-L-phenylalanine 2-naphthylamide (GPN). Our findings reveal that widely used concentrations of GPN rupture only a small fraction of lysosomes, but surprisingly trigger Ca 2+ release from nearly all. Chelating cytoplasmic Ca 2+ using BAPTA makes lysosomes more likely to rupture under GPN-induced stress, suggesting that Ca 2+ plays a role in protecting or rapidly repairing lysosomal membranes. Mechanistically, we establish that GPN causes the Ca 2+ -sensitive protein Apoptosis Linked Gene-2 (ALG-2) and interacting ESCRT proteins to redistribute onto lysosomes, improving their resistance to membrane stress created by GPN as well as the lysosomotropic drug chlorpromazine. Furthermore, we show that activating the cation channel TRPML1, with or without blocking the endoplasmic reticulum Ca 2+ pump, creates local Ca 2+ signals that protect lysosomes from rupture by recruiting ALG-2 and ESCRTs without any membrane damage. These findings reveal that Ca 2+ , through ALG-2, helps bring ESCRTs to lysosomes to enhance their resilience and maintain organelle integrity in the face of osmotic stress. SIGNIFICANCE As the degradative hub of the cell, lysosomes are full of toxic content that can spill into the cytoplasm. There has been much recent interest in how cells sense and repair lysosomal membrane damage using ESCRTs and cholesterol to rapidly fix "nanoscale damage". Here, we extend understanding of how ESCRTs contribute by uncovering a preventative role of the ESCRT machinery. We show that ESCRTs, when recruited by the Ca 2+ -sensor ALG-2, play a critical role in stabilizing the lysosomal membrane against osmotically-induced rupture. This finding suggests that cells have mechanisms not just for repairing but also for actively protecting lysosomes from stress-induced membrane damage.
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Nozaki K, Miao EA. Bucket lists must be completed during cell death. Trends Cell Biol 2023; 33:803-815. [PMID: 36958996 PMCID: PMC10440244 DOI: 10.1016/j.tcb.2023.02.008] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2022] [Revised: 02/23/2023] [Accepted: 02/24/2023] [Indexed: 03/25/2023]
Abstract
Regulated cell death occurs in many forms, including apoptosis, pyroptosis, necroptosis, and NETosis. Most obviously, the purpose of these pathways is to kill the cell. However, many cells need to complete a set of effector programs before they die, which we define as a cellular 'bucket list'. These effector programs are specific to the cell type, and mode and circumstances of death. For example, intestinal epithelial cells need to complete the process of extrusion before they die. Cells use regulatory mechanisms to temporarily prolong their life, including endosomal sorting complex required for transport (ESCRT)- and acid sphingomyelinase (ASM)-driven membrane repair. These allow cells to complete their bucket lists before they die.
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Affiliation(s)
- Kengo Nozaki
- Department of Immunology, Duke University School of Medicine, Durham, NC, USA; Department of Molecular Genetics and Microbiology, Duke University School of Medicine, Durham, NC, USA; Department of Cell Biology, Duke University School of Medicine, Durham, NC, USA.
| | - Edward A Miao
- Department of Immunology, Duke University School of Medicine, Durham, NC, USA; Department of Molecular Genetics and Microbiology, Duke University School of Medicine, Durham, NC, USA; Department of Cell Biology, Duke University School of Medicine, Durham, NC, USA.
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Tibolone Pre-Treatment Ameliorates the Dysregulation of Protein Translation and Transport Generated by Palmitic Acid-Induced Lipotoxicity in Human Astrocytes: A Label-Free MS-Based Proteomics and Network Analysis. Int J Mol Sci 2022; 23:ijms23126454. [PMID: 35742897 PMCID: PMC9223656 DOI: 10.3390/ijms23126454] [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: 04/29/2022] [Revised: 05/27/2022] [Accepted: 05/30/2022] [Indexed: 01/27/2023] Open
Abstract
Excessive accumulation and release of fatty acids (FAs) in adipose and non-adipose tissue are characteristic of obesity and are associated with the leading causes of death worldwide. Chronic exposure to high concentrations of FAs such as palmitic acid (pal) is a risk factor for developing different neurodegenerative diseases (NDs) through several mechanisms. In the brain, astrocytic dysregulation plays an essential role in detrimental processes like metabolic inflammatory state, oxidative stress, endoplasmic reticulum stress, and autophagy impairment. Evidence shows that tibolone, a synthetic steroid, induces neuroprotective effects, but its molecular mechanisms upon exposure to pal remain largely unknown. Due to the capacity of identifying changes in the whole data-set of proteins and their interaction allowing a deeper understanding, we used a proteomic approach on normal human astrocytes under supraphysiological levels of pal as a model to induce cytotoxicity, finding changes of expression in proteins related to translation, transport, autophagy, and apoptosis. Additionally, tibolone pre-treatment showed protective effects by restoring those same pal-altered processes and increasing the expression of proteins from cell survival processes. Interestingly, ARF3 and IPO7 were identified as relevant proteins, presenting a high weight in the protein-protein interaction network and significant differences in expression levels. These proteins are related to transport and translation processes, and their expression was restored by tibolone. This work suggests that the damage caused by pal in astrocytes simultaneously involves different mechanisms that the tibolone can partially revert, making tibolone interesting for further research to understand how to modulate these damages.
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Rivera-Cuevas Y, Mayoral J, Di Cristina M, Lawrence ALE, Olafsson EB, Patel RK, Thornhill D, Waldman BS, Ono A, Sexton JZ, Lourido S, Weiss LM, Carruthers VB. Toxoplasma gondii exploits the host ESCRT machinery for parasite uptake of host cytosolic proteins. PLoS Pathog 2021; 17:e1010138. [PMID: 34898650 PMCID: PMC8700025 DOI: 10.1371/journal.ppat.1010138] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2021] [Revised: 12/23/2021] [Accepted: 11/23/2021] [Indexed: 11/18/2022] Open
Abstract
Toxoplasma gondii is a master manipulator capable of effectively siphoning the resources from the host cell for its intracellular subsistence. However, the molecular underpinnings of how the parasite gains resources from its host remain largely unknown. Residing within a non-fusogenic parasitophorous vacuole (PV), the parasite must acquire resources across the limiting membrane of its replicative niche, which is decorated with parasite proteins including those secreted from dense granules. We discovered a role for the host Endosomal Sorting Complex Required for Transport (ESCRT) machinery in host cytosolic protein uptake by T. gondii by disrupting host ESCRT function. We identified the transmembrane dense granule protein TgGRA14, which contains motifs homologous to the late domain motifs of HIV-1 Gag, as a candidate for the recruitment of the host ESCRT machinery to the PV membrane. Using an HIV-1 virus-like particle (VLP) release assay, we found that the motif-containing portion of TgGRA14 is sufficient to substitute for HIV-1 Gag late domain to mediate ESCRT-dependent VLP budding. We also show that TgGRA14 is proximal to and interacts with host ESCRT components and other dense granule proteins during infection. Furthermore, analysis of TgGRA14-deficient parasites revealed a marked reduction in ingestion of a host cytosolic protein compared to WT parasites. Thus, we propose a model in which T. gondii recruits the host ESCRT machinery to the PV where it can interact with TgGRA14 for the internalization of host cytosolic proteins across the PV membrane (PVM). These findings provide new insight into how T. gondii accesses contents of the host cytosol by exploiting a key pathway for vesicular budding and membrane scission.
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Affiliation(s)
- Yolanda Rivera-Cuevas
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
| | - Joshua Mayoral
- Department of Pathology, Albert Einstein College of Medicine, Bronx, New York, New York, United States of America
| | - Manlio Di Cristina
- Department of Chemistry, Biology and Biotechnology, University of Perugia, Perugia, Italy
| | - Anna-Lisa E. Lawrence
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
| | - Einar B. Olafsson
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
| | - Romir K. Patel
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
| | - Dishari Thornhill
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
| | - Benjamin S. Waldman
- Whitehead Institute for Biomedical Research, Cambridge, Massachusetts, United States of America
- Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America
| | - Akira Ono
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
| | - Jonathan Z. Sexton
- Department of Medicinal Chemistry, College of Pharmacy, Ann Arbor, Michigan, United States of America
| | - Sebastian Lourido
- Whitehead Institute for Biomedical Research, Cambridge, Massachusetts, United States of America
- Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America
| | - Louis M. Weiss
- Department of Pathology, Albert Einstein College of Medicine, Bronx, New York, New York, United States of America
- Department of Medicine, Albert Einstein College of Medicine, Bronx, New York, New York, United States of America
| | - Vern B. Carruthers
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
- * E-mail:
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Ji W, Zhang L, Xu X, Liu X. ALG2 regulates type I interferon responses by inhibiting STING trafficking. J Cell Sci 2021; 134:273719. [PMID: 34787301 DOI: 10.1242/jcs.259060] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2021] [Accepted: 11/09/2021] [Indexed: 11/20/2022] Open
Abstract
Stimulator of IFN genes (STING), an endoplasmic reticulum (ER) signaling adaptor, is essential for the type I interferon response to cytosolic dsDNA. The translocation from the ER to perinuclear vesicles following binding cGAMP is a critical step for STING to activate downstream signaling molecules, which lead to the production of interferon and pro-inflammatory cytokines. Here we found that apoptosis-linked gene 2 (ALG2) suppressed STING signaling induced by either HSV-1 infection or cGAMP presence. Knockout of ALG2 markedly facilitated the expression of type I interferons upon cGAMP treatment or HSV-1 infection in THP-1 monocytes. Mechanistically, ALG2 associated with the C-terminal tail (CTT) of STING and inhibited its trafficking from ER to perinuclear region. Furthermore, the ability of ALG2 to coordinate calcium was crucial for its regulation of STING trafficking and DNA-induced innate immune responses. This work suggests that ALG2 is involved in DNA-induced innate immune responses by regulating STING trafficking.
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Affiliation(s)
- Wangsheng Ji
- State Key Laboratory of Medicinal Chemical Biology, Tianjin Key Laboratory of Protein Science, College of Life Sciences, Nankai University, Tianjin, China
| | - Lianfei Zhang
- State Key Laboratory of Medicinal Chemical Biology, Tianjin Key Laboratory of Protein Science, College of Life Sciences, Nankai University, Tianjin, China
| | - Xiaoyu Xu
- State Key Laboratory of Medicinal Chemical Biology, Tianjin Key Laboratory of Protein Science, College of Life Sciences, Nankai University, Tianjin, China
| | - Xinqi Liu
- State Key Laboratory of Medicinal Chemical Biology, Tianjin Key Laboratory of Protein Science, College of Life Sciences, Nankai University, Tianjin, China
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ALG2 Influences T cell apoptosis by regulating FASLG intracellular transportation. Biochem J 2021; 477:3105-3121. [PMID: 32766719 DOI: 10.1042/bcj20200028] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2020] [Revised: 08/06/2020] [Accepted: 08/06/2020] [Indexed: 12/16/2022]
Abstract
In the immune system, T lymphocytes undergo rapid clonal expansion upon pathogen infection. Following pathogen clearance, most of proliferated T cells will be eliminated by the apoptosis pathway to keep the balance of immune cells. FASLG, by interacting with its cognate receptor FAS, plays a major role in controlling the T cell death. FASLG is a type II transmembrane protein, with its C-terminal extracellular domain responsible for interacting with FAS. The N-terminal cytosolic region, despite short and intrinsically disordered, plays critical roles on the protein stability and transportation. The correct localization, either on the plasma membrane or secreted with exosome, or shed into the extracellular region after protease cleavage, has a great impact on the proper function of FASLG. Following synthesis, FASLG is transported by intracellular vesicle transportation system to the final destination. In this report, ALG2, a molecule identified in the T cell apoptosis and shown to be involved in vesicle trafficking previously, was found to interact with FASLG and regulate FASLG transportation. Therefore, we identified a new regulating factor for FASLG function within T cells and also revealed a new pathway for ALG2 involvement in T cell apoptosis.
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Inukai R, Mori K, Kuwata K, Suzuki C, Maki M, Takahara T, Shibata H. The Novel ALG-2 Target Protein CDIP1 Promotes Cell Death by Interacting with ESCRT-I and VAPA/B. Int J Mol Sci 2021; 22:ijms22031175. [PMID: 33503978 PMCID: PMC7865452 DOI: 10.3390/ijms22031175] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2020] [Revised: 01/20/2021] [Accepted: 01/21/2021] [Indexed: 12/15/2022] Open
Abstract
Apoptosis-linked gene 2 (ALG-2, also known as PDCD6) is a member of the penta-EF-hand (PEF) family of Ca2+-binding proteins. The murine gene encoding ALG-2 was originally reported to be an essential gene for apoptosis. However, the role of ALG-2 in cell death pathways has remained elusive. In the present study, we found that cell death-inducing p53 target protein 1 (CDIP1), a pro-apoptotic protein, interacts with ALG-2 in a Ca2+-dependent manner. Co-immunoprecipitation analysis of GFP-fused CDIP1 (GFP-CDIP1) revealed that GFP-CDIP1 associates with tumor susceptibility gene 101 (TSG101), a known target of ALG-2 and a subunit of endosomal sorting complex required for transport-I (ESCRT-I). ESCRT-I is a heterotetrameric complex composed of TSG101, VPS28, VPS37 and MVB12/UBAP1. Of diverse ESCRT-I species originating from four VPS37 isoforms (A, B, C, and D), CDIP1 preferentially associates with ESCRT-I containing VPS37B or VPS37C in part through the adaptor function of ALG-2. Overexpression of GFP-CDIP1 in HEK293 cells caused caspase-3/7-mediated cell death. In addition, the cell death was enhanced by co-expression of ALG-2 and ESCRT-I, indicating that ALG-2 likely promotes CDIP1-induced cell death by promoting the association between CDIP1 and ESCRT-I. We also found that CDIP1 binds to vesicle-associated membrane protein-associated protein (VAP)A and VAPB through the two phenylalanines in an acidic tract (FFAT)-like motif in the C-terminal region of CDIP1, mutations of which resulted in reduction of CDIP1-induced cell death. Therefore, our findings suggest that different expression levels of ALG-2, ESCRT-I subunits, VAPA and VAPB may have an impact on sensitivity of anticancer drugs associated with CDIP1 expression.
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Affiliation(s)
- Ryuta Inukai
- Department of Applied Biosciences, Graduate School of Bioagricultural Sciences, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8601, Japan; (R.I.); (K.M.); (C.S.); (M.M.); (T.T.)
| | - Kanako Mori
- Department of Applied Biosciences, Graduate School of Bioagricultural Sciences, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8601, Japan; (R.I.); (K.M.); (C.S.); (M.M.); (T.T.)
| | - Keiko Kuwata
- Institute of Transformative Bio-Molecules (WPI-ITbM), Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8601, Japan;
| | - Chihiro Suzuki
- Department of Applied Biosciences, Graduate School of Bioagricultural Sciences, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8601, Japan; (R.I.); (K.M.); (C.S.); (M.M.); (T.T.)
| | - Masatoshi Maki
- Department of Applied Biosciences, Graduate School of Bioagricultural Sciences, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8601, Japan; (R.I.); (K.M.); (C.S.); (M.M.); (T.T.)
| | - Terunao Takahara
- Department of Applied Biosciences, Graduate School of Bioagricultural Sciences, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8601, Japan; (R.I.); (K.M.); (C.S.); (M.M.); (T.T.)
| | - Hideki Shibata
- Department of Applied Biosciences, Graduate School of Bioagricultural Sciences, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8601, Japan; (R.I.); (K.M.); (C.S.); (M.M.); (T.T.)
- Correspondence:
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10
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The Penta-EF-Hand ALG-2 Protein Interacts with the Cytosolic Domain of the SOCE Regulator SARAF and Interferes with Ubiquitination. Int J Mol Sci 2020; 21:ijms21176315. [PMID: 32878247 PMCID: PMC7504102 DOI: 10.3390/ijms21176315] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2020] [Revised: 08/24/2020] [Accepted: 08/29/2020] [Indexed: 12/18/2022] Open
Abstract
ALG-2 is a penta-EF-hand Ca2+-binding protein and interacts with a variety of proteins in mammalian cells. In order to find new ALG-2-binding partners, we searched a human protein database and retrieved sequences containing the previously identified ALG-2-binding motif type 2 (ABM-2). After selecting 12 high-scored sequences, we expressed partial or full-length GFP-fused proteins in HEK293 cells and performed a semi-quantitative in vitro binding assay. SARAF, a negative regulator of store-operated Ca2+ entry (SOCE), showed the strongest binding activity. Biochemical analysis of Strep-tagged and GFP-fused SARAF proteins revealed ubiquitination that proceeded during pulldown assays under certain buffer conditions. Overexpression of ALG-2 interfered with ubiquitination of wild-type SARAF but not ubiquitination of the F228S mutant that had impaired ALG-2-binding activity. The SARAF cytosolic domain (CytD) contains two PPXY motifs targeted by the WW domains of NEDD4 family E3 ubiquitin ligases. The PPXY motif proximal to the ABM-2 sequence was found to be more important for both in-cell ubiquitination and post-cell lysis ubiquitination. A ubiquitination-defective mutant of SARAF with Lys-to-Arg substitutions in the CytD showed a slower degradation rate by half-life analysis. ALG-2 promoted Ca2+-dependent CytD-to-CytD interactions of SARAF. The ALG-2 dimer may modulate the stability of SARAF by sterically blocking ubiquitination and by bridging SARAF molecules at the CytDs.
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11
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Kjellin J, Pränting M, Bach F, Vaid R, Edelbroek B, Li Z, Hoeppner MP, Grabherr M, Isberg RR, Hagedorn M, Söderbom F. Investigation of the host transcriptional response to intracellular bacterial infection using Dictyostelium discoideum as a host model. BMC Genomics 2019; 20:961. [PMID: 31823727 PMCID: PMC6902447 DOI: 10.1186/s12864-019-6269-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2019] [Accepted: 11/07/2019] [Indexed: 12/17/2022] Open
Abstract
BACKGROUND During infection by intracellular pathogens, a highly complex interplay occurs between the infected cell trying to degrade the invader and the pathogen which actively manipulates the host cell to enable survival and proliferation. Many intracellular pathogens pose important threats to human health and major efforts have been undertaken to better understand the host-pathogen interactions that eventually determine the outcome of the infection. Over the last decades, the unicellular eukaryote Dictyostelium discoideum has become an established infection model, serving as a surrogate macrophage that can be infected with a wide range of intracellular pathogens. In this study, we use high-throughput RNA-sequencing to analyze the transcriptional response of D. discoideum when infected with Mycobacterium marinum and Legionella pneumophila. The results were compared to available data from human macrophages. RESULTS The majority of the transcriptional regulation triggered by the two pathogens was found to be unique for each bacterial challenge. Hallmark transcriptional signatures were identified for each infection, e.g. induction of endosomal sorting complexes required for transport (ESCRT) and autophagy genes in response to M. marinum and inhibition of genes associated with the translation machinery and energy metabolism in response to L. pneumophila. However, a common response to the pathogenic bacteria was also identified, which was not induced by non-pathogenic food bacteria. Finally, comparison with available data sets of regulation in human monocyte derived macrophages shows that the elicited response in D. discoideum is in many aspects similar to what has been observed in human immune cells in response to Mycobacterium tuberculosis and L. pneumophila. CONCLUSIONS Our study presents high-throughput characterization of D. discoideum transcriptional response to intracellular pathogens using RNA-seq. We demonstrate that the transcriptional response is in essence distinct to each pathogen and that in many cases, the corresponding regulation is recapitulated in human macrophages after infection by mycobacteria and L. pneumophila. This indicates that host-pathogen interactions are evolutionary conserved, derived from the early interactions between free-living phagocytic cells and bacteria. Taken together, our results strengthen the use of D. discoideum as a general infection model.
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Affiliation(s)
- Jonas Kjellin
- Department of Cell and Molecular Biology, Uppsala University, Uppsala, Sweden.
| | - Maria Pränting
- Department of Cell and Molecular Biology, Uppsala University, Uppsala, Sweden.,Present Address: ReAct - Action on Antibiotic Resistance, Department of Medical Sciences, Uppsala University, Uppsala, Sweden
| | - Frauke Bach
- Section Parasitology, Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany.,Present Address: Department of Stem Cell Transplantation, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Roshan Vaid
- Department of Cell and Molecular Biology, Uppsala University, Uppsala, Sweden.,Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden
| | - Bart Edelbroek
- Department of Cell and Molecular Biology, Uppsala University, Uppsala, Sweden
| | - Zhiru Li
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, MA, 02111, USA.,Present Address: New England Biolabs, Ipswich, MA, USA
| | - Marc P Hoeppner
- Department of Medical Biochemistry and Microbiology, Uppsala University, Uppsala, Sweden.,Institute of Clinical Molecular Biology, Kiel University, University Hospital Schleswig-Holstein, Kiel, Germany
| | - Manfred Grabherr
- Department of Medical Biochemistry and Microbiology, Uppsala University, Uppsala, Sweden
| | - Ralph R Isberg
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, MA, 02111, USA
| | - Monica Hagedorn
- Section Parasitology, Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany.,Life Sciences and Chemistry, Jacobs University Bremen gGmbH, Group Ribogenetics, Bremen, Germany
| | - Fredrik Söderbom
- Department of Cell and Molecular Biology, Uppsala University, Uppsala, Sweden.
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12
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Maki M. Structures and functions of penta-EF-hand calcium-binding proteins and their interacting partners: enigmatic relationships between ALG-2 and calpain-7. Biosci Biotechnol Biochem 2019; 84:651-660. [PMID: 31814542 DOI: 10.1080/09168451.2019.1700099] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
The penta-EF-hand (PEF) protein family includes ALG-2 (gene name, PDCD6) and its paralogs as well as classical calpain family members. ALG-2 is a prototypic PEF protein that is widely distributed in eukaryotes and interacts with a variety of proteins in a Ca2+-dependent manner. Mammalian ALG-2 and its interacting partners have various modulatory roles including roles in cell death, signal transduction, membrane repair, ER-to-Golgi vesicular transport, and RNA processing. Some ALG-2-interacting proteins are key factors that function in the endosomal sorting complex required for transport (ESCRT) system. On the other hand, mammalian calpain-7 (CAPN7) lacks the PEF domain but contains two microtubule-interacting and trafficking (MIT) domains in tandem. CAPN7 interacts with a subset of ESCRT-III proteins through the MIT domains and regulates EGF receptor downregulation. Structures and functions of ALG-2 and those of its interacting partners as well as relationships with the calpain family are reviewed in this article.
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Affiliation(s)
- Masatoshi Maki
- Department of Applied Biosciences, Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, Japan
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13
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Abstract
Cellular membranes can form two principally different involutions, which either exclude or contain cytosol. The 'classical' budding reactions, such as those occurring during endocytosis or formation of exocytic vesicles, involve proteins that assemble on the cytosol-excluding face of the bud neck. Inverse membrane involution occurs in a wide range of cellular processes, supporting cytokinesis, endosome maturation, autophagy, membrane repair and many other processes. Such inverse membrane remodelling is mediated by a heteromultimeric protein machinery known as endosomal sorting complex required for transport (ESCRT). ESCRT proteins assemble on the cytosolic (or nucleoplasmic) face of the neck of the forming involution and cooperate with the ATPase VPS4 to drive membrane scission or sealing. Here, we review similarities and differences of various ESCRT-dependent processes, with special emphasis on mechanisms of ESCRT recruitment.
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Zhang W, Matsuo R, Takahara T, Shibata H, Maki M. High Sensitive Quantitative Binding Assays Using a Nanoluciferase-Fused Probe for Analysis of ALG-2-Interacting Proteins. Methods Mol Biol 2019; 1929:501-516. [PMID: 30710293 DOI: 10.1007/978-1-4939-9030-6_31] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Many non-catalytic cellular proteins exert biological functions by formation of stable or transient complexes with other proteins. Analysis of the signal-induced physical interactions is important to understand their physiological roles in cells. Here we describe a biochemical method for assessing the binding of ALG-2 (gene name, PDCD6) to its target proteins that are immunoprecipitated from cell lysates. Application of nanoluciferase (Nluc)-fused ALG-2 enables a rapid quantitative evaluation of Ca2+-dependent interactions of target proteins with ALG-2 in vitro binding assays.
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Affiliation(s)
- Wei Zhang
- Department of Applied Molecular Biosciences, Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, Japan
| | - Rina Matsuo
- Department of Applied Molecular Biosciences, Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, Japan
| | - Terunao Takahara
- Department of Applied Molecular Biosciences, Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, Japan
| | - Hideki Shibata
- Department of Applied Molecular Biosciences, Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, Japan
| | - Masatoshi Maki
- Department of Applied Molecular Biosciences, Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, Japan.
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15
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Shibata H. Adaptor functions of the Ca 2+-binding protein ALG-2 in protein transport from the endoplasmic reticulum. Biosci Biotechnol Biochem 2018; 83:20-32. [PMID: 30259798 DOI: 10.1080/09168451.2018.1525274] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Apoptosis-linked gene 2 (ALG-2) is a Ca2+-binding protein with five repetitive EF-hand motifs, named penta-EF-hand (PEF) domain. It interacts with various target proteins and functions as a Ca2+-dependent adaptor in diverse cellular activities. In the cytoplasm, ALG-2 is predominantly localized to a specialized region of the endoplasmic reticulum (ER), called the ER exit site (ERES), through its interaction with Sec31A. Sec31A is an outer coat protein of coat protein complex II (COPII) and is recruited from the cytosol to the ERES to form COPII-coated transport vesicles. I will overview current knowledge of the physiological significance of ALG-2 in regulating ERES localization of Sec31A and the following adaptor functions of ALG-2, including bridging Sec31A and annexin A11 to stabilize Sec31A at the ERES, polymerizing the Trk-fused gene (TFG) product, and linking MAPK1-interacting and spindle stabilizing (MISS)-like (MISSL) and microtubule-associated protein 1B (MAP1B) to promote anterograde transport from the ER.
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Affiliation(s)
- Hideki Shibata
- a Department of Applied Biosciences, Graduate School of Bioagricultural Sciences , Nagoya University , Chikusa-ku , Nagoya , Japan
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16
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Ligation events influence ALG-2 dimerization. Biophys Chem 2018; 239:16-28. [DOI: 10.1016/j.bpc.2018.05.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2018] [Revised: 05/03/2018] [Accepted: 05/03/2018] [Indexed: 11/21/2022]
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Nanoluciferase Reporter Gene System Directed by Tandemly Repeated Pseudo-Palindromic NFAT-Response Elements Facilitates Analysis of Biological Endpoint Effects of Cellular Ca 2+ Mobilization. Int J Mol Sci 2018; 19:ijms19020605. [PMID: 29463029 PMCID: PMC5855827 DOI: 10.3390/ijms19020605] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2017] [Revised: 02/11/2018] [Accepted: 02/14/2018] [Indexed: 01/12/2023] Open
Abstract
NFAT is a cytoplasm-localized hyper-phosphorylated transcription factor that is activated through dephosphorylation by calcineurin, a Ca2+/calmodulin-dependent phosphatase. A non-palindromic NFAT-response element (RE) found in the IL2 promoter region has been commonly used for a Ca2+-response reporter gene system, but requirement of concomitant activation of AP-1 (Fos/Jun) often complicates the interpretation of obtained results. A new nanoluciferase (NanoLuc) reporter gene containing nine-tandem repeats of a pseudo-palindromic NFAT-RE located upstream of the IL8 promoter was designed to monitor Ca2+-induced transactivation activity of NFAT in human embryonic kidney (HEK) 293 cells by measuring luciferase activities of NanoLuc and co-expressed firefly luciferase for normalization. Ionomycin treatment enhanced the relative luciferase activity (RLA), which was suppressed by calcineurin inhibitors. HEK293 cells that stably express human STIM1 and Orai1, components of the store-operated calcium entry (SOCE) machinery, gave a much higher RLA by stimulation with thapsigargin, an inhibitor of sarcoplasmic/endoplamic reticulum Ca2+-ATPase (SERCA). HEK293 cells deficient in a penta-EF-hand Ca2+-binding protein ALG-2 showed a higher RLA value than the parental cells by stimulation with an acetylcholine receptor agonist carbachol. The novel reporter gene system is found to be useful for applications to cell signaling research to monitor biological endpoint effects of cellular Ca2+ mobilization.
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Villalobo A, Ishida H, Vogel HJ, Berchtold MW. Calmodulin as a protein linker and a regulator of adaptor/scaffold proteins. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2017; 1865:507-521. [PMID: 29247668 DOI: 10.1016/j.bbamcr.2017.12.004] [Citation(s) in RCA: 61] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/16/2017] [Revised: 12/07/2017] [Accepted: 12/08/2017] [Indexed: 01/29/2023]
Abstract
Calmodulin (CaM) is a universal regulator for a huge number of proteins in all eukaryotic cells. Best known is its function as a calcium-dependent modulator of the activity of enzymes, such as protein kinases and phosphatases, as well as other signaling proteins including membrane receptors, channels and structural proteins. However, less well known is the fact that CaM can also function as a Ca2+-dependent adaptor protein, either by bridging between different domains of the same protein or by linking two identical or different target proteins together. These activities are possible due to the fact that CaM contains two independently-folded Ca2+ binding lobes that are able to interact differentially and to some degree separately with targets proteins. In addition, CaM can interact with and regulates several proteins that function exclusively as adaptors. This review provides an overview over our present knowledge concerning the structural and functional aspects of the role of CaM as an adaptor protein and as a regulator of known adaptor/scaffold proteins.
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Affiliation(s)
- Antonio Villalobo
- Department of Cancer Biology, Instituto de Investigaciones Biomédicas, Consejo Superior de Investigaciones Científicas and Universidad Autónoma de Madrid, Arturo Duperier 4, E-28029 Madrid, Spain.
| | - Hiroaki Ishida
- Department of Biological Sciences, University of Calgary, 2500 University Dr. N.W., Calgary, Alberta T2N 1N4, Canada
| | - Hans J Vogel
- Department of Biological Sciences, University of Calgary, 2500 University Dr. N.W., Calgary, Alberta T2N 1N4, Canada.
| | - Martin W Berchtold
- Department of Biology, University of Copenhagen, 13 Universitetsparken, DK-2100 Copenhagen Ø, Denmark.
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Takahara T, Inoue K, Arai Y, Kuwata K, Shibata H, Maki M. The calcium-binding protein ALG-2 regulates protein secretion and trafficking via interactions with MISSL and MAP1B proteins. J Biol Chem 2017; 292:17057-17072. [PMID: 28864773 DOI: 10.1074/jbc.m117.800201] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2017] [Revised: 08/31/2017] [Indexed: 01/12/2023] Open
Abstract
Mobilization of intracellular calcium is essential for a wide range of cellular processes, including signal transduction, apoptosis, and vesicular trafficking. Several lines of evidence have suggested that apoptosis-linked gene 2 (ALG-2, also known as PDCD6), a calcium-binding protein, acts as a calcium sensor linking calcium levels with efficient vesicular trafficking, especially at the endoplasmic reticulum (ER)-to-Golgi transport step. However, how ALG-2 regulates these processes remains largely unclear. Here, we report that MAPK1-interacting and spindle-stabilizing (MISS)-like (MISSL), a previously uncharacterized protein, interacts with ALG-2 in a calcium-dependent manner. Live-cell imaging revealed that upon a rise in intracellular calcium levels, GFP-tagged MISSL (GFP-MISSL) dynamically relocalizes in a punctate pattern and colocalizes with ALG-2. MISSL knockdown caused disorganization of the components of the ER exit site, the ER-Golgi intermediate compartment, and Golgi. Importantly, knockdown of either MISSL or ALG-2 attenuated the secretion of secreted alkaline phosphatase (SEAP), a model secreted cargo protein, with similar reductions in secretion by single- and double-protein knockdowns, suggesting that MISSL and ALG-2 act in the same pathway to regulate the secretion process. Furthermore, ALG-2 or MISSL knockdown delayed ER-to-Golgi transport of procollagen type I. We also found that ALG-2 and MISSL interact with microtubule-associated protein 1B (MAP1B) and that MAP1B knockdown reverts the reduced secretion of SEAP caused by MISSL or ALG-2 depletion. These results suggest that a change in the intracellular calcium level plays a role in regulation of the secretory pathway via interaction of ALG-2 with MISSL and MAP1B.
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Affiliation(s)
- Terunao Takahara
- From the Department of Applied Molecular Biosciences, Graduate School of Bioagricultural Sciences, and
| | - Kuniko Inoue
- From the Department of Applied Molecular Biosciences, Graduate School of Bioagricultural Sciences, and
| | - Yumika Arai
- From the Department of Applied Molecular Biosciences, Graduate School of Bioagricultural Sciences, and
| | - Keiko Kuwata
- the Institute of Transformative Bio-Molecules (WPI-ITbM), Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi 464-8601, Japan
| | - Hideki Shibata
- From the Department of Applied Molecular Biosciences, Graduate School of Bioagricultural Sciences, and
| | - Masatoshi Maki
- From the Department of Applied Molecular Biosciences, Graduate School of Bioagricultural Sciences, and
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20
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Kaul Z, Chakrabarti O. Tumor susceptibility gene 101 regulates predisposition to apoptosis via ESCRT machinery accessory proteins. Mol Biol Cell 2017; 28:2106-2122. [PMID: 28539405 PMCID: PMC5509423 DOI: 10.1091/mbc.e16-12-0855] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2016] [Revised: 05/11/2017] [Accepted: 05/16/2017] [Indexed: 12/21/2022] Open
Abstract
ESCRT proteins are implicated in myriad cellular processes, including endosome formation, fusion of autophagosomes/amphisomes with lysosomes, and apoptosis. The role played by these proteins in either facilitating or protecting against apoptosis is unclear. In this study, while trying to understand how deficiency of Mahogunin RING finger 1 (MGRN1) affects cell viability, we uncovered a novel role for its interactor, the ESCRT-I protein TSG101: it directly participates in mitigating ER stress-mediated apoptosis. The association of TSG101 with ALIX prevents predisposition to apoptosis, whereas ALIX-ALG-2 interaction favors a death phenotype. Altered Ca2+ homeostasis in cells and a simultaneous increase in the protein levels of ALIX and ALG-2 are required to elicit apoptosis by activating ER stress-associated caspase 4/12. We further demonstrate that in the presence of membrane-associated, disease-causing prion protein CtmPrP, increased ALIX and ALG-2 levels are detected along with ER stress markers and associated caspases in transgenic brain lysates and cells. These effects were rescued by overexpression of TSG101. This is significant because MGRN1 deficiency is closely associated with neurodegeneration and prenatal and neonatal mortality, which could be due to excess cell death in selected brain regions or myocardial apoptosis during embryonic development.
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Affiliation(s)
- Zenia Kaul
- Biophysics and Structural Genomics Division, Saha Institute of Nuclear Physics, Kolkata 700064, India
| | - Oishee Chakrabarti
- Biophysics and Structural Genomics Division, Saha Institute of Nuclear Physics, Kolkata 700064, India
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21
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Smith BN, Topp SD, Fallini C, Shibata H, Chen HJ, Troakes C, King A, Ticozzi N, Kenna KP, Soragia-Gkazi A, Miller JW, Sato A, Dias DM, Jeon M, Vance C, Wong CH, de Majo M, Kattuah W, Mitchell JC, Scotter EL, Parkin NW, Sapp PC, Nolan M, Nestor PJ, Simpson M, Weale M, Lek M, Baas F, Vianney de Jong JM, Ten Asbroek ALMA, Redondo AG, Esteban-Pérez J, Tiloca C, Verde F, Duga S, Leigh N, Pall H, Morrison KE, Al-Chalabi A, Shaw PJ, Kirby J, Turner MR, Talbot K, Hardiman O, Glass JD, De Belleroche J, Maki M, Moss SE, Miller C, Gellera C, Ratti A, Al-Sarraj S, Brown RH, Silani V, Landers JE, Shaw CE. Mutations in the vesicular trafficking protein annexin A11 are associated with amyotrophic lateral sclerosis. Sci Transl Med 2017; 9:eaad9157. [PMID: 28469040 PMCID: PMC6599403 DOI: 10.1126/scitranslmed.aad9157] [Citation(s) in RCA: 117] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2015] [Revised: 08/16/2016] [Accepted: 01/04/2017] [Indexed: 01/05/2023]
Abstract
Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disorder. We screened 751 familial ALS patient whole-exome sequences and identified six mutations including p.D40G in the ANXA11 gene in 13 individuals. The p.D40G mutation was absent from 70,000 control whole-exome sequences. This mutation segregated with disease in two kindreds and was present in another two unrelated cases (P = 0.0102), and all mutation carriers shared a common founder haplotype. Annexin A11-positive protein aggregates were abundant in spinal cord motor neurons and hippocampal neuronal axons in an ALS patient carrying the p.D40G mutation. Transfected human embryonic kidney cells expressing ANXA11 with the p.D40G mutation and other N-terminal mutations showed altered binding to calcyclin, and the p.R235Q mutant protein formed insoluble aggregates. We conclude that mutations in ANXA11 are associated with ALS and implicate defective intracellular protein trafficking in disease pathogenesis.
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Affiliation(s)
- Bradley N Smith
- United Kingdom Dementia Research Institute Centre, Maurice Wohl Clinical Neuroscience Institute, Institute of Psychiatry, Psychology and Neuroscience, King's College London, 125 Coldharbour Lane, Camberwell, SE5 9NU London, UK
| | - Simon D Topp
- United Kingdom Dementia Research Institute Centre, Maurice Wohl Clinical Neuroscience Institute, Institute of Psychiatry, Psychology and Neuroscience, King's College London, 125 Coldharbour Lane, Camberwell, SE5 9NU London, UK
| | - Claudia Fallini
- Department of Neurology, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Hideki Shibata
- Department of Applied Molecular Biosciences, Graduate School of Bioagricultural Sciences, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8601, Japan
| | - Han-Jou Chen
- United Kingdom Dementia Research Institute Centre, Maurice Wohl Clinical Neuroscience Institute, Institute of Psychiatry, Psychology and Neuroscience, King's College London, 125 Coldharbour Lane, Camberwell, SE5 9NU London, UK
| | - Claire Troakes
- United Kingdom Dementia Research Institute Centre, Maurice Wohl Clinical Neuroscience Institute, Institute of Psychiatry, Psychology and Neuroscience, King's College London, 125 Coldharbour Lane, Camberwell, SE5 9NU London, UK
| | - Andrew King
- United Kingdom Dementia Research Institute Centre, Maurice Wohl Clinical Neuroscience Institute, Institute of Psychiatry, Psychology and Neuroscience, King's College London, 125 Coldharbour Lane, Camberwell, SE5 9NU London, UK
| | - Nicola Ticozzi
- Department of Neurology and Laboratory of Neuroscience, Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS) Istituto Auxologico Italiano, 20149 Milan, Italy
- Department of Pathophysiology and Transplantation, "Dino Ferrari" Center, University of Milan, 20122 Milan, Italy
| | - Kevin P Kenna
- Department of Neurology, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Athina Soragia-Gkazi
- United Kingdom Dementia Research Institute Centre, Maurice Wohl Clinical Neuroscience Institute, Institute of Psychiatry, Psychology and Neuroscience, King's College London, 125 Coldharbour Lane, Camberwell, SE5 9NU London, UK
| | - Jack W Miller
- United Kingdom Dementia Research Institute Centre, Maurice Wohl Clinical Neuroscience Institute, Institute of Psychiatry, Psychology and Neuroscience, King's College London, 125 Coldharbour Lane, Camberwell, SE5 9NU London, UK
| | - Akane Sato
- Department of Applied Molecular Biosciences, Graduate School of Bioagricultural Sciences, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8601, Japan
| | - Diana Marques Dias
- United Kingdom Dementia Research Institute Centre, Maurice Wohl Clinical Neuroscience Institute, Institute of Psychiatry, Psychology and Neuroscience, King's College London, 125 Coldharbour Lane, Camberwell, SE5 9NU London, UK
| | - Maryangel Jeon
- Department of Neurology, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Caroline Vance
- United Kingdom Dementia Research Institute Centre, Maurice Wohl Clinical Neuroscience Institute, Institute of Psychiatry, Psychology and Neuroscience, King's College London, 125 Coldharbour Lane, Camberwell, SE5 9NU London, UK
| | - Chun Hao Wong
- United Kingdom Dementia Research Institute Centre, Maurice Wohl Clinical Neuroscience Institute, Institute of Psychiatry, Psychology and Neuroscience, King's College London, 125 Coldharbour Lane, Camberwell, SE5 9NU London, UK
| | - Martina de Majo
- United Kingdom Dementia Research Institute Centre, Maurice Wohl Clinical Neuroscience Institute, Institute of Psychiatry, Psychology and Neuroscience, King's College London, 125 Coldharbour Lane, Camberwell, SE5 9NU London, UK
| | - Wejdan Kattuah
- United Kingdom Dementia Research Institute Centre, Maurice Wohl Clinical Neuroscience Institute, Institute of Psychiatry, Psychology and Neuroscience, King's College London, 125 Coldharbour Lane, Camberwell, SE5 9NU London, UK
| | - Jacqueline C Mitchell
- United Kingdom Dementia Research Institute Centre, Maurice Wohl Clinical Neuroscience Institute, Institute of Psychiatry, Psychology and Neuroscience, King's College London, 125 Coldharbour Lane, Camberwell, SE5 9NU London, UK
| | - Emma L Scotter
- Centre for Brain Research, Faculty of Medical and Health Sciences, University of Auckland, 85 Park Road, Grafton, Auckland, New Zealand
| | - Nicholas W Parkin
- Molecular Genetics Laboratory, Viapath, Genetics Centre, Guy's Hospital, Great Maze Pond, SE1 9RT London, UK
| | - Peter C Sapp
- Department of Neurology, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Matthew Nolan
- United Kingdom Dementia Research Institute Centre, Maurice Wohl Clinical Neuroscience Institute, Institute of Psychiatry, Psychology and Neuroscience, King's College London, 125 Coldharbour Lane, Camberwell, SE5 9NU London, UK
| | - Peter J Nestor
- German Center for Neurodegenerative Diseases, Leipziger Str. 44, 39120 Magdeburg, Germany
| | - Michael Simpson
- Medical & Molecular Genetics, Division of Genetics and Molecular Medicine, King's College London, Guy's Tower, London Bridge, SE1 9RT London, UK
| | - Michael Weale
- Medical & Molecular Genetics, Division of Genetics and Molecular Medicine, King's College London, Guy's Tower, London Bridge, SE1 9RT London, UK
| | - Monkel Lek
- Analytic and Translational Genetics Unit, Massachusetts General Hospital, Boston, MA 02114, USA
- Program in Medical and Population Genetics, Broad Institute of Massachusetts Institute of Technology and Harvard, Cambridge, MA 02142, USA
| | - Frank Baas
- Department of Genome Analysis, University of Amsterdam, Academic Medical Centre, P.O. Box 22700, 1100DE Amsterdam, Netherlands
| | - J M Vianney de Jong
- Department of Genome Analysis, University of Amsterdam, Academic Medical Centre, P.O. Box 22700, 1100DE Amsterdam, Netherlands
| | - Anneloor L M A Ten Asbroek
- Department of Genome Analysis, University of Amsterdam, Academic Medical Centre, P.O. Box 22700, 1100DE Amsterdam, Netherlands
| | - Alberto Garcia Redondo
- Unidad de ELA, Instituto de Investigación Hospital 12 de Octubre de Madrid, SERMAS, and Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), U-723 Madrid, Spain
| | - Jesús Esteban-Pérez
- Unidad de ELA, Instituto de Investigación Hospital 12 de Octubre de Madrid, SERMAS, and Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), U-723 Madrid, Spain
| | - Cinzia Tiloca
- Department of Neurology and Laboratory of Neuroscience, Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS) Istituto Auxologico Italiano, 20149 Milan, Italy
- Department of Pathophysiology and Transplantation, "Dino Ferrari" Center, University of Milan, 20122 Milan, Italy
| | - Federico Verde
- Department of Neurology and Laboratory of Neuroscience, Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS) Istituto Auxologico Italiano, 20149 Milan, Italy
- Department of Pathophysiology and Transplantation, "Dino Ferrari" Center, University of Milan, 20122 Milan, Italy
| | - Stefano Duga
- Department of Biomedical Sciences, Humanitas University, Rozzano, Milan, Italy
- Humanitas Clinical and Research Center, Via Manzoni 56, 20089 Rozzano, Milan, Italy
| | - Nigel Leigh
- Trafford Centre for Medical Research, Brighton and Sussex Medical School, BN1 9RY Brighton, UK
| | - Hardev Pall
- School of Clinical and Experimental Medicine, College of Medical and Dental Sciences, University of Birmingham, Birmingham, UK
| | - Karen E Morrison
- University of Southampton, Southampton General Hospital, SO16 6YD, UK
| | - Ammar Al-Chalabi
- United Kingdom Dementia Research Institute Centre, Maurice Wohl Clinical Neuroscience Institute, Institute of Psychiatry, Psychology and Neuroscience, King's College London, 125 Coldharbour Lane, Camberwell, SE5 9NU London, UK
| | - Pamela J Shaw
- Sheffield Institute for Translational Neuroscience, University of Sheffield, Sheffield, UK
| | - Janine Kirby
- Sheffield Institute for Translational Neuroscience, University of Sheffield, Sheffield, UK
| | - Martin R Turner
- Nuffield Department of Clinical Neurosciences, John Radcliffe Hospital, Oxford, UK
| | - Kevin Talbot
- Nuffield Department of Clinical Neurosciences, John Radcliffe Hospital, Oxford, UK
| | - Orla Hardiman
- Academic Unit of Neurology, Trinity Biomedical Sciences Institute, Trinity College Dublin, Dublin, Republic of Ireland
| | - Jonathan D Glass
- Department of Neurology, Center for Neurodegenerative Disease, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Jacqueline De Belleroche
- Neurogenetics Group, Division of Brain Sciences, Imperial College London, Hammersmith Hospital Campus, Burlington Danes Building, Du Cane Road, W12 0NN London, UK
| | - Masatoshi Maki
- Department of Applied Molecular Biosciences, Graduate School of Bioagricultural Sciences, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8601, Japan
| | - Stephen E Moss
- Institute of Ophthalmology, University College London, 11-43 Bath Street, EC1V 9EL London, UK
| | - Christopher Miller
- United Kingdom Dementia Research Institute Centre, Maurice Wohl Clinical Neuroscience Institute, Institute of Psychiatry, Psychology and Neuroscience, King's College London, 125 Coldharbour Lane, Camberwell, SE5 9NU London, UK
| | - Cinzia Gellera
- Unit of Genetics of Neurodegenerative and Metabolic Diseases, Fondazione IRCCS Istituto Neurologico "Carlo Besta," 20133 Milan, Italy
| | - Antonia Ratti
- Department of Neurology and Laboratory of Neuroscience, Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS) Istituto Auxologico Italiano, 20149 Milan, Italy
- Department of Pathophysiology and Transplantation, "Dino Ferrari" Center, University of Milan, 20122 Milan, Italy
| | - Safa Al-Sarraj
- United Kingdom Dementia Research Institute Centre, Maurice Wohl Clinical Neuroscience Institute, Institute of Psychiatry, Psychology and Neuroscience, King's College London, 125 Coldharbour Lane, Camberwell, SE5 9NU London, UK
| | - Robert H Brown
- Department of Neurology, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Vincenzo Silani
- Department of Neurology and Laboratory of Neuroscience, Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS) Istituto Auxologico Italiano, 20149 Milan, Italy
- Department of Pathophysiology and Transplantation, "Dino Ferrari" Center, University of Milan, 20122 Milan, Italy
| | - John E Landers
- Department of Neurology, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Christopher E Shaw
- United Kingdom Dementia Research Institute Centre, Maurice Wohl Clinical Neuroscience Institute, Institute of Psychiatry, Psychology and Neuroscience, King's College London, 125 Coldharbour Lane, Camberwell, SE5 9NU London, UK.
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Kanadome T, Shibata H, Kuwata K, Takahara T, Maki M. The calcium-binding protein ALG-2 promotes endoplasmic reticulum exit site localization and polymerization of Trk-fused gene (TFG) protein. FEBS J 2017; 284:56-76. [PMID: 27813252 DOI: 10.1111/febs.13949] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2016] [Revised: 09/28/2016] [Accepted: 11/01/2016] [Indexed: 12/27/2022]
Abstract
Apoptosis-linked gene 2 (ALG-2), which is a gene product of PDCD6, is a 22-kDa Ca2+ -binding protein. Accumulating evidence points to a role for ALG-2 as a Ca2+ -responsive adaptor protein. On binding to Ca2+ , ALG-2 undergoes a conformational change that facilitates its interaction with various proteins. It also forms a homodimer and heterodimer with peflin, a paralog of ALG-2. However, the differences in cellular roles for the ALG-2 homodimer and ALG-2/peflin heterodimer are unclear. In the present study, we found that Trk-fused gene (TFG) protein interacted with the ALG-2 homodimer. Immunostaining analysis revealed that TFG and ALG-2 partially overlapped at endoplasmic reticulum exit sites (ERES), a platform for COPII-mediated protein transport from the endoplasmic reticulum. Time-lapse live-cell imaging demonstrated that both green fluorescent protein-fused TFG and mCherry-fused ALG-2 are recruited to ERES after thapsigargin treatment, which raises intracellular Ca2+ levels. Furthermore, overexpression of ALG-2 induced the accumulation of TFG at ERES. TFG has an ALG-2-binding motif and deletion of the motif decreased TFG binding to ALG-2 and shortened its half-life at ERES, suggesting a critical role for ALG-2 in retaining TFG at ERES. We also demonstrated, by in vitro cross-linking assays, that ALG-2 promoted the polymerization of TFG in a Ca2+ -dependent manner. Collectively, the results suggest that ALG-2 acts as a Ca2+ -sensitive adaptor to concentrate and polymerize TFG at ERES, supporting a potential role for ALG-2 in COPII-dependent trafficking from the endoplasmic reticulum.
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Affiliation(s)
- Takashi Kanadome
- Department of Applied Molecular Biosciences, Graduate School of Bioagricultural Sciences, Nagoya University, Japan
| | - Hideki Shibata
- Department of Applied Molecular Biosciences, Graduate School of Bioagricultural Sciences, Nagoya University, Japan
| | - Keiko Kuwata
- Institute of Transformative Bio-Molecules (WPI-ITbM), Nagoya University, Japan
| | - Terunao Takahara
- Department of Applied Molecular Biosciences, Graduate School of Bioagricultural Sciences, Nagoya University, Japan
| | - Masatoshi Maki
- Department of Applied Molecular Biosciences, Graduate School of Bioagricultural Sciences, Nagoya University, Japan
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Ma J, Zhang X, Feng Y, Zhang H, Wang X, Zheng Y, Qiao W, Liu X. Structural and Functional Study of Apoptosis-linked Gene-2·Heme-binding Protein 2 Interactions in HIV-1 Production. J Biol Chem 2016; 291:26670-26685. [PMID: 27784779 DOI: 10.1074/jbc.m116.752444] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2016] [Revised: 10/01/2016] [Indexed: 01/10/2023] Open
Abstract
In the HIV-1 replication cycle, the endosomal sorting complex required for transport (ESCRT) machinery promotes viral budding and release in the late stages. In this process, the ESCRT proteins, ALIX and TSG101, are recruited through interactions with HIV-1 Gag p6. ALG-2, also known as PDCD6, interacts with both ALIX and TSG101 and bridges ESCRT-III and ESCRT-I. In this study, we show that ALG-2 affects HIV-1 production negatively at both the exogenous and endogenous levels. Through a yeast two-hybrid screen, we identified HEBP2 as the binding partner of ALG-2, and we solved the crystal structure of the ALG-2·HEBP2 complex. The function of ALG-2·HEBP2 complex in HIV-1 replication was further explored. ALG-2 inhibits HIV-1 production by affecting Gag expression and distribution, and HEBP2 might aid this process by tethering ALG-2 in the cytoplasm.
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Affiliation(s)
- Jing Ma
- From the State Key Laboratory of Medicinal Chemical Biology, College of Life Sciences, Nankai University, Tianjin 300071.,the Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, College of Life Sciences, Nankai University, Tianjin 300071, China
| | - Xianfeng Zhang
- the CAAS-Michigan State University Joint Laboratory of Innate Immunity, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin 150069, and
| | - Yanbin Feng
- From the State Key Laboratory of Medicinal Chemical Biology, College of Life Sciences, Nankai University, Tianjin 300071
| | - Hui Zhang
- From the State Key Laboratory of Medicinal Chemical Biology, College of Life Sciences, Nankai University, Tianjin 300071
| | - Xiaojun Wang
- the CAAS-Michigan State University Joint Laboratory of Innate Immunity, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin 150069, and
| | - Yonghui Zheng
- the CAAS-Michigan State University Joint Laboratory of Innate Immunity, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin 150069, and
| | - Wentao Qiao
- From the State Key Laboratory of Medicinal Chemical Biology, College of Life Sciences, Nankai University, Tianjin 300071, .,the Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, College of Life Sciences, Nankai University, Tianjin 300071, China
| | - Xinqi Liu
- From the State Key Laboratory of Medicinal Chemical Biology, College of Life Sciences, Nankai University, Tianjin 300071,
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24
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Tanner JJ, Frey BB, Pemberton T, Henzl MT. EF5 Is the High-Affinity Mg2+ Site in ALG-2. Biochemistry 2016; 55:5128-41. [DOI: 10.1021/acs.biochem.6b00596] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- John J. Tanner
- Department
of Biochemistry, University of Missouri, Columbia, Missouri 65211, United States
- Department
of Chemistry, University of Missouri, Columbia, Missouri 65211, United States
| | - Benjamin B. Frey
- Department
of Biochemistry, University of Missouri, Columbia, Missouri 65211, United States
| | - Travis Pemberton
- Department
of Chemistry, University of Missouri, Columbia, Missouri 65211, United States
| | - Michael T. Henzl
- Department
of Biochemistry, University of Missouri, Columbia, Missouri 65211, United States
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25
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Maki M, Takahara T, Shibata H. Multifaceted Roles of ALG-2 in Ca(2+)-Regulated Membrane Trafficking. Int J Mol Sci 2016; 17:ijms17091401. [PMID: 27571067 PMCID: PMC5037681 DOI: 10.3390/ijms17091401] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2016] [Revised: 08/18/2016] [Accepted: 08/19/2016] [Indexed: 12/15/2022] Open
Abstract
ALG-2 (gene name: PDCD6) is a penta-EF-hand Ca2+-binding protein and interacts with a variety of proteins in a Ca2+-dependent fashion. ALG-2 recognizes different types of identified motifs in Pro-rich regions by using different hydrophobic pockets, but other unknown modes of binding are also used for non-Pro-rich proteins. Most ALG-2-interacting proteins associate directly or indirectly with the plasma membrane or organelle membranes involving the endosomal sorting complex required for transport (ESCRT) system, coat protein complex II (COPII)-dependent ER-to-Golgi vesicular transport, and signal transduction from membrane receptors to downstream players. Binding of ALG-2 to targets may induce conformational change of the proteins. The ALG-2 dimer may also function as a Ca2+-dependent adaptor to bridge different partners and connect the subnetwork of interacting proteins.
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Affiliation(s)
- Masatoshi Maki
- Department of Applied Molecular Biosciences, Graduate School of Bioagricultural Sciences, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8601, Japan.
| | - Terunao Takahara
- Department of Applied Molecular Biosciences, Graduate School of Bioagricultural Sciences, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8601, Japan.
| | - Hideki Shibata
- Department of Applied Molecular Biosciences, Graduate School of Bioagricultural Sciences, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8601, Japan.
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26
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Henzl MT, Frey BB, Wolf AJ. ALG-2 divalent-ion affinity: Calorimetric analysis of the des23 versions reveals high-affinity site for Mg(2). Biophys Chem 2015; 209:28-40. [PMID: 26705706 DOI: 10.1016/j.bpc.2015.10.009] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2015] [Accepted: 10/27/2015] [Indexed: 12/29/2022]
Affiliation(s)
- Michael T Henzl
- Department of Biochemistry, University of Missouri, Columbia, MO, 65211.
| | - Benjamin B Frey
- Department of Biochemistry, University of Missouri, Columbia, MO, 65211
| | - Andrew J Wolf
- Department of Biochemistry, University of Missouri, Columbia, MO, 65211
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27
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Structural analysis of the complex between penta-EF-hand ALG-2 protein and Sec31A peptide reveals a novel target recognition mechanism of ALG-2. Int J Mol Sci 2015; 16:3677-99. [PMID: 25667979 PMCID: PMC4346919 DOI: 10.3390/ijms16023677] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2015] [Accepted: 01/30/2015] [Indexed: 02/07/2023] Open
Abstract
ALG-2, a 22-kDa penta-EF-hand protein, is involved in cell death, signal transduction, membrane trafficking, etc., by interacting with various proteins in mammalian cells in a Ca2+-dependent manner. Most known ALG-2-interacting proteins contain proline-rich regions in which either PPYPXnYP (type 1 motif) or PXPGF (type 2 motif) is commonly found. Previous X-ray crystal structural analysis of the complex between ALG-2 and an ALIX peptide revealed that the peptide binds to the two hydrophobic pockets. In the present study, we resolved the crystal structure of the complex between ALG-2 and a peptide of Sec31A (outer shell component of coat complex II, COPII; containing the type 2 motif) and found that the peptide binds to the third hydrophobic pocket (Pocket 3). While amino acid substitution of Phe85, a Pocket 3 residue, with Ala abrogated the interaction with Sec31A, it did not affect the interaction with ALIX. On the other hand, amino acid substitution of Tyr180, a Pocket 1 residue, with Ala caused loss of binding to ALIX, but maintained binding to Sec31A. We conclude that ALG-2 recognizes two types of motifs at different hydrophobic surfaces. Furthermore, based on the results of serial mutational analysis of the ALG-2-binding sites in Sec31A, the type 2 motif was newly defined.
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28
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Shibata H, Kanadome T, Sugiura H, Yokoyama T, Yamamuro M, Moss SE, Maki M. A new role for annexin A11 in the early secretory pathway via stabilizing Sec31A protein at the endoplasmic reticulum exit sites (ERES). J Biol Chem 2014; 290:4981-4993. [PMID: 25540196 DOI: 10.1074/jbc.m114.592089] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Exit of cargo molecules from the endoplasmic reticulum (ER) for transport to the Golgi is the initial step in intracellular vesicular trafficking. The coat protein complex II (COPII) machinery is recruited to specialized regions of the ER, called ER exit sites (ERES), where it plays a central role in the early secretory pathway. It has been known for more than two decades that calcium is an essential factor in vesicle trafficking from the ER to Golgi apparatus. However, the role of calcium in the early secretory pathway is complicated and poorly understood. We and others previously identified Sec31A, an outer cage component of COPII, as an interacting protein for the penta-EF-hand calcium-binding protein ALG-2. In this study, we show that another calcium-binding protein, annexin A11 (AnxA11), physically associates with Sec31A by the adaptor function of ALG-2. Depletion of AnxA11 or ALG-2 decreases the population of Sec31A that is stably associated with the ERES and causes scattering of juxtanuclear ERES to the cell periphery. The synchronous ER-to-Golgi transport of transmembrane cargoes is accelerated in AnxA11- or ALG-2-knockdown cells. These findings suggest that AnxA11 maintains architectural and functional features of the ERES by coordinating with ALG-2 to stabilize Sec31A at the ERES.
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Affiliation(s)
- Hideki Shibata
- From the Department of Applied Molecular Biosciences, Graduate School of Bioagricultural Sciences, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8601, Japan and.
| | - Takashi Kanadome
- From the Department of Applied Molecular Biosciences, Graduate School of Bioagricultural Sciences, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8601, Japan and
| | - Hirofumi Sugiura
- From the Department of Applied Molecular Biosciences, Graduate School of Bioagricultural Sciences, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8601, Japan and
| | - Takeru Yokoyama
- From the Department of Applied Molecular Biosciences, Graduate School of Bioagricultural Sciences, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8601, Japan and
| | - Minami Yamamuro
- From the Department of Applied Molecular Biosciences, Graduate School of Bioagricultural Sciences, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8601, Japan and
| | - Stephen E Moss
- the Department of Cell Biology, UCL Institute of Ophthalmology, University College London, 11-43 Bath Street, London EC1V 9EL, United Kingdom
| | - Masatoshi Maki
- From the Department of Applied Molecular Biosciences, Graduate School of Bioagricultural Sciences, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8601, Japan and
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29
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Sasaki-Osugi K, Imoto C, Takahara T, Shibata H, Maki M. Nuclear ALG-2 protein interacts with Ca2+ homeostasis endoplasmic reticulum protein (CHERP) Ca2+-dependently and participates in regulation of alternative splicing of inositol trisphosphate receptor type 1 (IP3R1) pre-mRNA. J Biol Chem 2013; 288:33361-75. [PMID: 24078636 DOI: 10.1074/jbc.m113.497479] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
The intracellular Ca(2+) signaling pathway is important for the control of broad cellular processes from fertilization to cell death. ALG-2 is a Ca(2+)-binding protein that contains five serially repeated EF-hand motifs and interacts with various proteins in a Ca(2+)-dependent manner. Although ALG-2 is present both in the cytoplasm and in the nucleus, little is known about its nuclear function. Ca(2+) homeostasis endoplasmic reticulum protein (CHERP) was first identified as an endoplasmic reticulum protein that regulates intracellular Ca(2+) mobilization in human cells, but recent proteomics data suggest an association between CHERP and spliceosomes. Here, we report that CHERP, containing a Pro-rich region and a phosphorylated Ser/Arg-rich RS-like domain, is a novel Ca(2+)-dependent ALG-2-interactive target in the nucleus. Immunofluorescence microscopic analysis revealed localization of CHERP to the nucleoplasm with prominent accumulation at nuclear speckles, which are the sites of storage and modification for pre-mRNA splicing factors. Live cell time-lapse imaging showed that nuclear ALG-2 was recruited to the CHERP-localizing speckles upon Ca(2+) mobilization. Results of co-immunoprecipitation assays revealed binding of CHERP to a phosphorylated form of RNA polymerase II. Knockdown of CHERP or ALG-2 in HT1080 cells resulted in generation of alternatively spliced isoforms of the inositol 1,4,5-trisphosphate receptor 1 (IP3R1) pre-mRNA that included exons 41 and 42 in addition to the major isoform lacking exons 40-42. Furthermore, binding between CHERP and IP3R1 RNA was detected by an RNA immunoprecipitation assay using a polyclonal antibody against CHERP. These results indicate that CHERP and ALG-2 participate in regulation of alternative splicing of IP3R1 pre-mRNA and provide new insights into post-transcriptional regulation of splicing variants in Ca(2+) signaling pathways.
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Affiliation(s)
- Kanae Sasaki-Osugi
- From the Department of Applied Molecular Biosciences, Graduate School of Bioagricultural Sciences, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8601, Japan
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30
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VPS37 isoforms differentially modulate the ternary complex formation of ALIX, ALG-2, and ESCRT-I. Biosci Biotechnol Biochem 2013; 77:1715-21. [PMID: 23924735 DOI: 10.1271/bbb.130280] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The endosomal sorting complex required for transport (ESCRT) system comprises a series of protein complexes that play essential roles in multivesicular body (MVB) sorting of ubiquitylated membrane proteins, enveloped RNA virus budding, and cytokinesis in mammalian cells. The complex, named ESCRT-I, consists of four subunits (TSG101, VPS28, VPS37, and MVB12). There are four VPS37 isoforms. We have reported that ALIX (an ALG-2-interacting protein and accessory protein in the ESCRT system) is physically linked with TSG101 by ALG-2 in a Ca²⁺-dependent manner, but the role of ALG-2 as an adaptor protein for the ESCRT-I complex remains unknown. To characterize this adaptor function, initially we investigated the binding of ALG-2 to ESCRT-I complexes containing each one of the four different VPS37 isoforms by two approaches: first, Far-Western blot analysis with biotin-labeled ALG-2 probe, and second, a pulldown assay to determine the binding of the four recombinant ESCRT-I complexes to Strep-tagged ALG-2 after co-expression in HEK293T cells. VPS37B and VPS37C appeared to interact with ALG-2 in a stronger manner than TSG101 does. The results of in vitro binding assays using purified recombinant proteins indicated that ALG-2 functions as a Ca²⁺-dependent adaptor protein that bridges ALIX and ESCRT-I to form a ternary complex, ESCRT-I/ALIX/ALG-2.
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31
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Mammalian ESCRT-III-related protein IST1 has a distinctive met-pro repeat sequence that is essential for interaction with ALG-2 in the presence of Ca2+. Biosci Biotechnol Biochem 2013; 77:1049-54. [PMID: 23649269 DOI: 10.1271/bbb.130022] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
ALG-2 is an EF-hand-type Ca(2+)-binding protein that interacts with a variety of intracellular proteins that possess Pro-rich regions (PRRs) in mammalian cells. IST1 is an endosomal sorting complex required for transport (ESCRT)-III-related charged multivesicular body protein (CHMP)-like protein, but unlike other ESCRT-III proteins, mammalian IST1 has a PRR and a distinctive sequence of Met-Pro repeats. We found that ALG-2 binds to IST1 by Far-Western analysis using biotinylated ALG-2 as probe, and that the Met-Pro repeat sequence is essential for interaction. The results of pulldown assays using Strep-tagged ALG-2 and lysates of cells expressing GFP-fused IST1 proteins indicated that the binding of ALG-2 to IST1 is Ca(2+)-dependent, and that it is enhanced by co-expression with CHMP1 proteins. Moreover, pulldown assays using various mutants of GST-ALG-2 revealed that the ability of IST1 to bind to mutants is different from those of known ALG-2-interacting proteins, suggesting that IST1 binds to ALG-2 by a different mode of recognition.
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32
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Maemoto Y, Kiso S, Shibata H, Maki M. Analysis of limited proteolytic activity of calpain-7 using non-physiological substrates in mammalian cells. FEBS J 2013; 280:2594-607. [DOI: 10.1111/febs.12243] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2012] [Revised: 02/27/2013] [Accepted: 03/11/2013] [Indexed: 11/29/2022]
Affiliation(s)
- Yuki Maemoto
- Department of Applied Molecular Biosciences; Graduate School of Bioagricultural Sciences; Nagoya University; Chikusa-ku; Japan
| | - Satomi Kiso
- Department of Applied Molecular Biosciences; Graduate School of Bioagricultural Sciences; Nagoya University; Chikusa-ku; Japan
| | - Hideki Shibata
- Department of Applied Molecular Biosciences; Graduate School of Bioagricultural Sciences; Nagoya University; Chikusa-ku; Japan
| | - Masatoshi Maki
- Department of Applied Molecular Biosciences; Graduate School of Bioagricultural Sciences; Nagoya University; Chikusa-ku; Japan
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33
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Zhang K, Zhou B, Shi S, Song Y, Zhang L. Variations in the PDCD6 gene are associated with increased uterine leiomyoma risk in the Chinese. Genet Test Mol Biomarkers 2013; 17:524-8. [PMID: 23551056 DOI: 10.1089/gtmb.2012.0461] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Programmed cell death 6 (PDCD6) participates in T cell receptor, Fas, and glucocorticoid-induced programmed cell death. To test the relationship between PDCD6 polymorphisms and uterine leiomyomas (UL) risk, we investigated the association of two SNPs (rs4957014 and rs3756712) in PDCD6 with UL risk in a case-control study of 295 unrelated premenopausal UL patients and 436 healthy postmenopausal control subjects in a population of China. Genotypes of the two SNPs were determined with the use of PCR-restriction fragment length polymorphism assay. Significantly increased UL risks were found to be associated with the T allele of rs4957014 and the T allele of rs3756712 (p=0.016, odds ratio [OR]=1.325, 95% confidence intervals [CI]=1.053-1.668 for rs4957014; p<0.0001, OR=1.898, 95% CI=1.457-2.474 for rs3756712, respectively). Increased UL risks were associated with them in different genetic models. The present study provided evidence that rs4957014 and rs3756712 are associated with UL risk, the results indicated that genetic polymorphisms in PDCD6 may contribute to the development of UL.
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Affiliation(s)
- Kui Zhang
- Department of Forensic Biology, West China School of Preclinical and Forensic Medicine, Sichuan University, Chengdu, People's Republic of China
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ALG-2-interacting Tubby-like protein superfamily member PLSCR3 is secreted by an exosomal pathway and taken up by recipient cultured cells. Biosci Rep 2013; 33:e00026. [PMID: 23350699 PMCID: PMC3590573 DOI: 10.1042/bsr20120123] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
PLSCRs (phospholipid scramblases) are palmitoylated membrane-associating proteins. Regardless of the given names, their physiological functions are not clear and thought to be unrelated to phospholipid scrambling activities observed in vitro. Using a previously established cell line of HEK-293 (human embryonic kidney-293) cells constitutively expressing human Scr3 (PLSCR3) that interacts with ALG-2 (apoptosis-linked gene 2) Ca2+-dependently, we found that Scr3 was secreted into the culture medium. Secretion of Scr3 was suppressed by 2-BP (2-bromopalmitate, a palmitoylation inhibitor) and by GW4869 (an inhibitor of ceramide synthesis). Secreted Scr3 was recovered in exosomal fractions by sucrose density gradient centrifugation. Palmitoylation sites and the N-terminal Pro-rich region were necessary for efficient secretion, but ABSs (ALG-2-binding sites) were dispensable. Overexpression of GFP (green fluorescent protein)-fused VPS4BE235Q, a dominant negative mutant of an AAA (ATPase associated with various cellular activities) ATPase with a defect in disassembling ESCRT (endosomal sorting complex required for transport)-III subunits, significantly reduced secretion of Scr3. Immunofluorescence microscopic analyses showed that Scr3 was largely localized to enlarged endosomes induced by overexpression of a GFP-fused constitutive active mutant of Rab5A (GFP–Rab5AQ79L). Secreted Scr3 was taken up by HeLa cells, suggesting that Scr3 functions as a cell-to-cell transferable modulator carried by exosomes in a paracrine manner.
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35
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Takahashi T, Suzuki H, Inuzuka T, Shibata H, Maki M. Prediction of a new ligand-binding site for type 2 motif based on the crystal structure of ALG-2 by dry and wet approaches. Int J Mol Sci 2012; 13:7532-7549. [PMID: 22837710 PMCID: PMC3397542 DOI: 10.3390/ijms13067532] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2012] [Revised: 06/06/2012] [Accepted: 06/13/2012] [Indexed: 12/12/2022] Open
Abstract
ALG-2 is a penta-EF-hand Ca2+-binding protein and interacts with a variety of intracellular proteins. Two types of ALG-2-binding motifs have been determined: type 1, PXYPXnYP (X, variable; n = 4), in ALIX and PLSCR3; type 2, PXPGF, in Sec31A and PLSCR3. The previously solved X-ray crystal structure of the complex between ALG-2 and an ALIX peptide containing type 1 motif showed that the peptide binds to Pocket 1 and Pocket 2. Co-crystallization of ALG-2 and type 2 motif-containing peptides has not been successful. To gain insights into the molecular basis of type 2 motif recognition, we searched for a new hydrophobic cavity by computational algorithms using MetaPocket 2.0 based on 3D structures of ALG-2. The predicted hydrophobic pocket designated Pocket 3 fits with N-acetyl-ProAlaProGlyPhe-amide, a virtual penta-peptide derived from one of the two types of ALG-2-binding sites in PLSCR3 (type 2 motif), using the molecular docking software AutoDock Vina. We investigated effects of amino acid substitutions of the predicted binding sites on binding abilities by pulldown assays using glutathione-S-transferase -fused ALG-2 of wild-type and mutant proteins and lysates of cells expressing green fluorescent protein -fused PLSCR3 of wild-type and mutants. Substitution of either L52 with Ala or F148 with Ser of ALG-2 caused loss of binding abilities to PLSCR3 lacking type 1 motif but retained those to PLSCR3 lacking type 2 motif, strongly supporting the hypothesis that Pocket 3 is the binding site for type 2 motif.
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Affiliation(s)
| | | | | | | | - Masatoshi Maki
- Author to whom correspondence should be addressed; E-Mail: ; Tel.: +81-52-789-4088; Fax: +81-52-789-5542
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36
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Maki M, Maemoto Y, Osako Y, Shibata H. Evolutionary and physical linkage between calpains and penta-EF-hand Ca2+-binding proteins. FEBS J 2012; 279:1414-21. [PMID: 22404899 DOI: 10.1111/j.1742-4658.2012.08560.x] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The name calpain was historically given to a protease that is activated by Ca(2+) and whose primary structure contains a Ca(2+)-binding penta-EF-hand (PEF) as well as a calpain cysteine protease (CysPc) domain and a C2-domain-like (C2L) domain. In the human genome, CysPc domains are found in 15 genes, but only nine of them encode PEF domains. Fungi and budding yeasts have calpain-like sequences that lack the PEF domain, and each protein (designated PalB and Rim13, respectively) is orthologous to human calpain-7, indicating that the calpain-7 orthologs are evolutionarily more conserved than classical calpains possessing PEF domains. An N-terminal region of calpain-7 has a tandem repeat of microtubule-interacting and transport domains that interact with a subset of endosomal sorting complex required for transport (ESCRT) III proteins. In addition to calpains, PEF domains are found in other Ca(2+)-binding proteins including ALG-2 that associates with ALIX (an ESCRT-III accessory protein) and TSG101 (an ESCRT-I subunit). Phylogenetic comparison of dissected domain structures of calpains and experimentally confirmed protein-protein interaction networks imply that there is an evolutionary and physical linkage between mammalian calpains and PEF proteins involving the ESCRT system.
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Affiliation(s)
- Masatoshi Maki
- Department of Applied Molecular Biosciences, Graduate School of Bioagricultural Sciences, Nagoya University, Chikusa-ku, Nagoya, Japan.
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Osugi K, Suzuki H, Nomura T, Ariumi Y, Shibata H, Maki M. Identification of the P-body component PATL1 as a novel ALG-2-interacting protein by in silico and far-Western screening of proline-rich proteins. J Biochem 2012; 151:657-66. [PMID: 22437941 DOI: 10.1093/jb/mvs029] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
ALG-2 (also named PDCD6) is a 22-kDa Ca(2+)-binding protein that belongs to the penta-EF-hand family including calpain small subunit and interacts with various proteins such as ALIX and Sec31A at their specific sites containing an ALG-2-binding motif (ABM) present in their respective Pro-rich region (PRR). In this study, to search for novel ALG-2-interacting proteins, we first performed in silico screening of ABM-containing PRRs in a human protein database. After selecting 17 sequences, we expressed the PRR or full-length proteins fused with green fluorescent protein (GFP) in HEK293T cells and analysed their abilities to bind to ALG-2 by Far-Western blotting using biotinylated ALG-2 as a probe. As a result, we found 10 positive new ALG-2-binding candidates with different degrees of binding ability. For further investigation, we selected PATL1 (alternatively designated Pat1b), a component of the P-body, which is a cytoplasmic non-membranous granule composed of translation-inactive mRNAs and proteins involved in mRNA decay. Interactions between endogenous PATL1 and ALG-2 proteins were demonstrated by a co-immunoprecipitation assay using their specific antibodies. Furthermore, in immunofluorescence microscopic analyses, PATL1 as well as DCP1A, a well-known P-body marker, co-localized with a subset of ALG-2. This is the first report showing interaction of ALG-2 with a P-body component.
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Affiliation(s)
- Kanae Osugi
- Department of Applied Molecular Biosciences, Graduate School of Bioagricultural Sciences, Nagoya University, Chikusa-ku, Nagoya, Japan
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Abstract
Most membrane-enveloped viruses bud from infected cells by hijacking the host ESCRT machinery. The ESCRTs are recruited to the budding sites by viral proteins that contain short proline (Pro)-rich motifs (PRMs) known as late domains. The late domains probably evolved by co-opting host PRMs involved in the normal functions of ESCRTs in endosomal sorting and cytokinesis. The solution and crystal structures of PRMs bound to their interaction partners explain the conserved roles of Pro and other residues that predominate in these sequences. PRMs are often grouped together in much larger Pro-rich regions (PRRs) of as many as 150 residues. The PRR of the ESCRT-associated protein, ALIX, autoregulates its conformation and activity. The robustness of different viral budding and host pathways to impairments in Pro-based interactions varies considerably. The known biology of PRM recognition in the ESCRT pathway seems, in principle, compatible with antiviral development, given our increasingly nuanced understanding of the relative weakness and robustness of the host and viral processes.
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Affiliation(s)
- Xuefeng Ren
- Laboratory of Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - James H. Hurley
- Laboratory of Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA
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Maki M, Suzuki H, Shibata H. Structure and function of ALG-2, a penta-EF-hand calcium-dependent adaptor protein. SCIENCE CHINA-LIFE SCIENCES 2011; 54:770-9. [PMID: 21786200 DOI: 10.1007/s11427-011-4204-8] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/11/2011] [Accepted: 06/05/2011] [Indexed: 12/29/2022]
Abstract
ALG-2 (a gene product of PDCD6) is a 22-kD protein containing five serially repetitive EF-hand structures and belongs to the penta-EF-hand (PEF) family, including the subunits of typical calpains. ALG-2 is the most conserved protein among the PEF family members and its homologs are widely found in eukaryotes. X-ray crystal structures of various PEF proteins including ALG-2 have common features: presence of eight α-helices and dimer formation via paired EF5s that are positioned in anti-parallel orientation. ALG-2 forms a homodimer and a heterodimer with its closest paralog peflin. Like calmodulin, a well-known four-EF-hand protein, ALG-2 interacts with various proteins in a Ca(2+)-dependent fashion, but the binding motifs are completely different. With some exceptions, ALG-2-interacting proteins commonly contain Pro-rich regions, and ALG-2 recognizes at least two distinct Pro-containing motifs: PPYP(X)nYP (X, variable; n=4 in ALIX and PLSCR3) and PXPGF (represented by Sec31A). A shorter alternatively spliced isoform, lacking two residues and designated ALG-2(ΔGF122), does not bind ALIX but maintains binding capacity to Sec31A. X-ray crystal structural analyses have revealed that binding of calcium ions induces the configuration of the side chain of R125 so that it opens Pocket 1, which accepts PPYP, but Pocket 1 remains closed in the case of ALG-2(ΔGF122). ALG-2 dimer has two ligand-binding sites, each in a monomer molecule, and appears to function as a Ca(2+)-dependent adaptor protein to either stabilize a preformed complex or to bridge two proteins on scaffolds in systems of the endosomal sorting complex required for transport (ESCRT) and ER-to-Golgi transport.
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Affiliation(s)
- Masatoshi Maki
- Department of Applied Molecular Biosciences, Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, Japan.
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Abe K, Puertollano R. Role of TRP channels in the regulation of the endosomal pathway. Physiology (Bethesda) 2011; 26:14-22. [PMID: 21357899 DOI: 10.1152/physiol.00048.2010] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Some members of the transient receptor potential (TRP) channel superfamily have proved to be essential in maintaining adequate ion homeostasis, signaling, and membrane trafficking in the endosomal pathway. The unique properties of the TRP channels confer cells the ability to integrate cytosolic and intraluminal stimuli and allow maintained and regulated release of Ca(2+) from endosomes and lysosomes.
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Affiliation(s)
- Ken Abe
- Laboratory of Cell Biology, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland, USA
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The ALG-2 binding site in Sec31A influences the retention kinetics of Sec31A at the endoplasmic reticulum exit sites as revealed by live-cell time-lapse imaging. Biosci Biotechnol Biochem 2010; 74:1819-26. [PMID: 20834162 DOI: 10.1271/bbb.100215] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
ALG-2, a member of the penta-EF-hand protein family, interacts Ca²+-dependently with a COPII component, Sec31A. In this study, we first established HeLa cells stably expressing green fluorescent protein-fused ALG-2 (GFP-ALG-2) and red fluorescent protein-fused Sec31A (Sec31A-RFP). After inducing Ca²+-mobilization, the cytoplasmic distribution of GFP-ALG-2 changed from a diffuse to a punctate pattern, which extensively overlapped with the Sec31A-RFP-positive structures, indicating that ALG-2 is recruited to the endoplasmic reticulum exit sites (ERES) in living cells. Next, overlay experiments with biotin-labeled ALG-2 were done to dissect the ALG-2 binding site (ABS). They revealed that a sequence comprising amino acid residues 839-851 in the Pro-rich region was necessary and sufficient for direct binding to ALG-2. Finally, fluorescence recovery after photobleaching analysis indicated that the ABS deletion reduced the high-affinity population of Sec31A to the ERES, suggesting that the ABS is one of the key determinants of the retention kinetics of Sec31A at ERES.
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Inuzuka T, Suzuki H, Kawasaki M, Shibata H, Wakatsuki S, Maki M. Molecular basis for defect in Alix-binding by alternatively spliced isoform of ALG-2 (ALG-2DeltaGF122) and structural roles of F122 in target recognition. BMC STRUCTURAL BIOLOGY 2010; 10:25. [PMID: 20691033 PMCID: PMC2927601 DOI: 10.1186/1472-6807-10-25] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/15/2010] [Accepted: 08/06/2010] [Indexed: 11/10/2022]
Abstract
Background ALG-2 (a gene product of PDCD6) belongs to the penta-EF-hand (PEF) protein family and Ca2+-dependently interacts with various intracellular proteins including mammalian Alix, an adaptor protein in the ESCRT system. Our previous X-ray crystal structural analyses revealed that binding of Ca2+ to EF3 enables the side chain of R125 to move enough to make a primary hydrophobic pocket (Pocket 1) accessible to a short fragment of Alix. The side chain of F122, facing a secondary hydrophobic pocket (Pocket 2), interacts with the Alix peptide. An alternatively spliced shorter isoform, designated ALG-2ΔGF122, lacks Gly121Phe122 and does not bind Alix, but the structural basis of the incompetence has remained to be elucidated. Results We solved the X-ray crystal structure of the PEF domain of ALG-2ΔGF122 in the Ca2+-bound form and compared it with that of ALG-2. Deletion of the two residues shortened α-helix 5 (α5) and changed the configuration of the R125 side chain so that it partially blocked Pocket 1. A wall created by the main chain of 121-GFG-123 and facing the two pockets was destroyed. Surprisingly, however, substitution of F122 with Ala or Gly, but not with Trp, increased the Alix-binding capacity in binding assays. The F122 substitutions exhibited different effects on binding of ALG-2 to other known interacting proteins, including TSG101 (Tumor susceptibility gene 101) and annexin A11. The X-ray crystal structure of the F122A mutant revealed that removal of the bulky F122 side chain not only created an additional open space in Pocket 2 but also abolished inter-helix interactions with W95 and V98 (present in α4) and that α5 inclined away from α4 to expand Pocket 2, suggesting acquirement of more appropriate positioning of the interacting residues to accept Alix. Conclusions We found that the inability of the two-residue shorter ALG-2 isoform to bind Alix is not due to the absence of bulky side chain of F122 but due to deformation of a main-chain wall facing pockets 1 and 2. Moreover, a residue at the position of F122 contributes to target specificity and a smaller side chain is preferable for Alix binding but not favored to bind annexin A11.
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Affiliation(s)
- Tatsutoshi Inuzuka
- Department of Applied Molecular Biosciences, Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya 464-8601, Japan
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Abstract
Components of the ESCRT (endosomal sorting complex required for transport) machinery mediate endosomal sorting of ubiquitinated membrane proteins. They are key regulators of biological processes important for cell growth and survival, such as growth-factor-mediated signalling and cytokinesis. In addition, enveloped viruses, such as HIV-1, hijack and utilize the ESCRTs for budding during virus release and infection. Obviously, the ESCRT-facilitated pathways require tight regulation, which is partly mediated by a group of interacting proteins, for which our knowledge is growing. In this review we discuss the different ESCRT-modulating proteins and how they influence ESCRT-dependent processes, for example, by acting as positive or negative regulators or by providing temporal and spatial control. A number of the interactors influence the classical ESCRT-mediated process of endosomal cargo sorting, for example, by modulating the interaction between ubiquitinated cargo and the ESCRTs. Certain accessory proteins have been implicated in regulating the activity or steady-state expression levels of the ESCRT components, whereas other interactors control the cellular localization of the ESCRTs, for example, by inducing shuttling between cytosol and nucleus or endosomes. In conclusion, the discovery of novel interactors has and will extend our knowledge of the biological roles of ESCRTs.
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Bentley M, Nycz DC, Joglekar A, Fertschai I, Malli R, Graier WF, Hay JC. Vesicular calcium regulates coat retention, fusogenicity, and size of pre-Golgi intermediates. Mol Biol Cell 2010; 21:1033-46. [PMID: 20089833 PMCID: PMC2836956 DOI: 10.1091/mbc.e09-10-0914] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
This study establishes a role for luminal Ca2+ in ER/Golgi transport organelles and elucidates an effector mechanism involving the EF-hand protein ALG-2 and regulation of COPII coat retention. The significance and extent of Ca2+ regulation of the biosynthetic secretory pathway have been difficult to establish, and our knowledge of regulatory relationships integrating Ca2+ with vesicle coats and function is rudimentary. Here, we investigated potential roles and mechanisms of luminal Ca2+ in the early secretory pathway. Specific depletion of luminal Ca2+ in living normal rat kidney cells using cyclopiazonic acid (CPA) resulted in the extreme expansion of vesicular tubular cluster (VTC) elements. Consistent with this, a suppressive role for vesicle-associated Ca2+ in COPII vesicle homotypic fusion was demonstrated in vitro using Ca2+ chelators. The EF-hand–containing protein apoptosis-linked gene 2 (ALG-2), previously implicated in the stabilization of sec31 at endoplasmic reticulum exit sites, inhibited COPII vesicle fusion in a Ca2+-requiring manner, suggesting that ALG-2 may be a sensor for the effects of vesicular Ca2+ on homotypic fusion. Immunoisolation established that Ca2+ chelation inhibits and ALG-2 specifically favors residual retention of the COPII outer shell protein sec31 on pre-Golgi fusion intermediates. We conclude that vesicle-associated Ca2+, acting through ALG-2, favors the retention of residual coat molecules that seem to suppress membrane fusion. We propose that in cells, these Ca2+-dependent mechanisms temporally regulate COPII vesicle interactions, VTC biogenesis, cargo sorting, and VTC maturation.
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Affiliation(s)
- Marvin Bentley
- Division of Biological Sciences and Center for Structural and Functional Neuroscience, The University of Montana, Missoula, MT 59812-4824, USA
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Vergarajauregui S, Martina JA, Puertollano R. Identification of the penta-EF-hand protein ALG-2 as a Ca2+-dependent interactor of mucolipin-1. J Biol Chem 2009; 284:36357-36366. [PMID: 19864416 DOI: 10.1074/jbc.m109.047241] [Citation(s) in RCA: 71] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Loss of function mutations in mucolipin-1 (MCOLN1) have been linked to mucolipidosis type IV (MLIV), a recessive lysosomal storage disease characterized by severe neurological and ophthalmological abnormalities. MCOLN1 is an ion channel that regulates membrane transport along the endolysosomal pathway. It has been suggested that MCOLN1 participates in several Ca(2+)-dependent processes, including fusion of lysosomes with the plasma membrane, fusion of late endosomes and autophagosomes with lysosomes, and lysosomal biogenesis. Here, we searched for proteins that interact with MCOLN1 in a Ca(2+)-dependent manner. We found that the penta-EF-hand protein ALG-2 binds to the NH-terminal cytosolic tail of MCOLN1. The interaction is direct, strictly dependent on Ca(2+), and mediated by a patch of charged and hydrophobic residues located between MCOLN1 residues 37 and 49. We further show that MCOLN1 and ALG-2 co-localize to enlarged endosomes induced by overexpression of an ATPase-defective dominant-negative form of Vps4B (Vps4B(E235Q)). In agreement with the proposed role of MCOLN1 in the regulation of fusion/fission events, we found that overexpression of MCOLN1 caused accumulation of enlarged, aberrant endosomes that contain both early and late endosome markers. Interestingly, aggregation of abnormal endosomes was greatly reduced when the ALG-2-binding domain in MCOLN1 was mutated, suggesting that ALG-2 regulates MCOLN1 function. Overall, our data provide new insight into the molecular mechanisms that regulate MCOLN1 activity. We propose that ALG-2 acts as a Ca(2+) sensor that modulates the function of MCOLN1 along the late endosomal-lysosomal pathway.
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Affiliation(s)
- Silvia Vergarajauregui
- Laboratory of Cell Biology, NHLBI, National Institutes of Health, Bethesda, Maryland 20892
| | - Jose A Martina
- Laboratory of Cell Biology, NHLBI, National Institutes of Health, Bethesda, Maryland 20892
| | - Rosa Puertollano
- Laboratory of Cell Biology, NHLBI, National Institutes of Health, Bethesda, Maryland 20892.
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