1
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Liu D, Yuan H, Chen S, Ferro-Novick S, Novick P. Different ER-plasma membrane tethers play opposing roles in autophagy of the cortical ER. Proc Natl Acad Sci U S A 2024; 121:e2321991121. [PMID: 38838012 PMCID: PMC11181077 DOI: 10.1073/pnas.2321991121] [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: 12/13/2023] [Accepted: 05/08/2024] [Indexed: 06/07/2024] Open
Abstract
The endoplasmic reticulum (ER) undergoes degradation by selective macroautophagy (ER-phagy) in response to starvation or the accumulation of misfolded proteins within its lumen. In yeast, actin assembly at sites of contact between the cortical ER (cER) and endocytic pits acts to displace elements of the ER from their association with the plasma membrane (PM) so they can interact with the autophagosome assembly machinery near the vacuole. A collection of proteins tether the cER to the PM. Of these, Scs2/22 and Ist2 are required for cER-phagy, most likely through their roles in lipid transport, while deletion of the tricalbins, TCB1/2/3, bypasses those requirements. An artificial ER-PM tether blocks cER-phagy in both the wild type (WT) and a strain lacking endogenous tethers, supporting the importance of cER displacement from the PM. Scs2 and Ist2 can be cross-linked to the selective cER-phagy receptor, Atg40. The COPII cargo adaptor subunit, Lst1, associates with Atg40 and is required for cER-phagy. This requirement is also bypassed by deletion of the ER-PM tethers, suggesting a role for Lst1 prior to the displacement of the cER from the PM during cER-phagy. Although pexophagy and mitophagy also require actin assembly, deletion of ER-PM tethers does not bypass those requirements. We propose that within the context of rapamycin-induced cER-phagy, Scs2/22, Ist2, and Lst1 promote the local displacement of an element of the cER from the cortex, while Tcb1/2/3 act in opposition, anchoring the cER to the plasma membrane.
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Affiliation(s)
- Dongmei Liu
- Department of Cellular and Molecular Medicine, University of California San Diego, La Jolla, CA92093-0668
| | - Hua Yuan
- Department of Cellular and Molecular Medicine, University of California San Diego, La Jolla, CA92093-0668
| | - Shuliang Chen
- Department of Cellular and Molecular Medicine, University of California San Diego, La Jolla, CA92093-0668
| | - Susan Ferro-Novick
- Department of Cellular and Molecular Medicine, University of California San Diego, La Jolla, CA92093-0668
| | - Peter Novick
- Department of Cellular and Molecular Medicine, University of California San Diego, La Jolla, CA92093-0668
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2
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Mora S, Stuckert A, von Huth Friis R, Pietersz K, Noes-Holt G, Montañana-Rosell R, Wang H, Sørensen AT, Selvan R, Verhaagen J, Allodi I. Stabilization of V1 interneuron-motor neuron connectivity ameliorates motor phenotype in a mouse model of ALS. Nat Commun 2024; 15:4867. [PMID: 38849367 PMCID: PMC11161600 DOI: 10.1038/s41467-024-48925-7] [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: 02/21/2023] [Accepted: 05/17/2024] [Indexed: 06/09/2024] Open
Abstract
Loss of connectivity between spinal V1 inhibitory interneurons and motor neurons is found early in disease in the SOD1G93A mice. Such changes in premotor inputs can contribute to homeostatic imbalance of motor neurons. Here, we show that the Extended Synaptotagmin 1 (Esyt1) presynaptic organizer is downregulated in V1 interneurons. V1 restricted overexpression of Esyt1 rescues inhibitory synapses, increases motor neuron survival, and ameliorates motor phenotypes. Two gene therapy approaches overexpressing ESYT1 were investigated; one for local intraspinal delivery, and the other for systemic administration using an AAV-PHP.eB vector delivered intravenously. Improvement of motor functions is observed in both approaches, however systemic administration appears to significantly reduce onset of motor impairment in the SOD1G93A mice in absence of side effects. Altogether, we show that stabilization of V1 synapses by ESYT1 overexpression has the potential to improve motor functions in ALS, demonstrating that interneurons can be a target to attenuate ALS symptoms.
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Affiliation(s)
- Santiago Mora
- Department of Neuroscience, University of Copenhagen, Copenhagen, Denmark
- School of Psychology and Neuroscience, University of St Andrews, St Andrews, UK
| | - Anna Stuckert
- Department of Neuroscience, University of Copenhagen, Copenhagen, Denmark
- School of Psychology and Neuroscience, University of St Andrews, St Andrews, UK
| | | | - Kimberly Pietersz
- The Netherlands Institute for Neuroscience, Amsterdam, The Netherlands
| | - Gith Noes-Holt
- Department of Neuroscience, University of Copenhagen, Copenhagen, Denmark
| | | | - Haoyu Wang
- School of Psychology and Neuroscience, University of St Andrews, St Andrews, UK
| | | | - Raghavendra Selvan
- Department of Computer Science, University of Copenhagen, Copenhagen, Denmark
| | - Joost Verhaagen
- The Netherlands Institute for Neuroscience, Amsterdam, The Netherlands
| | - Ilary Allodi
- Department of Neuroscience, University of Copenhagen, Copenhagen, Denmark.
- School of Psychology and Neuroscience, University of St Andrews, St Andrews, UK.
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3
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Elgendy M, Tamada H, Taira T, Iio Y, Kawamura A, Kunogi A, Mizutani Y, Kiyama H. Dynamic changes in endoplasmic reticulum morphology and its contact with the plasma membrane in motor neurons in response to nerve injury. Cell Tissue Res 2024; 396:71-84. [PMID: 38311679 PMCID: PMC10997708 DOI: 10.1007/s00441-024-03858-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2023] [Accepted: 12/29/2023] [Indexed: 02/06/2024]
Abstract
The endoplasmic reticulum (ER) extends throughout a cell and plays a critical role in maintaining cellular homeostasis. Changes in ER shape could provide a clue to explore the mechanisms that underlie the fate determination of neurons after axon injury because the ER drastically changes its morphology under neuronal stress to maintain cellular homeostasis and recover from damage. Because of their tiny structures and richness in the soma, the detailed morphology of the ER and its dynamics have not been well analysed. In this study, the focused ion beam/scanning electron microscopy (FIB/SEM) analysis was performed to explore the ultra-structures of the ER in the somata of motor neuron with axon regenerative injury models. In normal motor neurons, ER in the somata is abundantly localised near the perinucleus and represents lamella-like structures. After injury, analysis of the ER volume and ER branching points indicated a collapse of the normal distribution and a transformation from lamella-like structures to mesh-like structures. Furthermore, accompanied by ER accumulation near the plasma membrane (PM), the contact between the ER and PM (ER-PM contacts) significantly increased after injury. The accumulation of extended-synaptotagmin 1 (E-Syt1), a tethering protein of the ER and PM that regulates Ca2+-dependent lipid transfer, was also identified by immunohistochemistry and quantitative Real-time PCR after injury. These morphological alterations of ER and the increase in ER-PM contacts may be crucial events that occur in motor neurons as a resilient response for the survival after axonal injury.
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Affiliation(s)
- Mahmoud Elgendy
- Functional Anatomy and Neuroscience, Nagoya University Graduate School of Medicine, 65 Tsurumai, Showa-Ku, Nagoya, Aichi, 466-8550, Japan
- Department of Anatomy and Embryology, Faculty of Veterinary Medicine, Damanhour University, Damanhour, 22511, Egypt
| | - Hiromi Tamada
- Functional Anatomy and Neuroscience, Nagoya University Graduate School of Medicine, 65 Tsurumai, Showa-Ku, Nagoya, Aichi, 466-8550, Japan.
- Anatomy, Graduate School of Medicines, University of Fukui, Matsuokashimoaizuki, Eiheiji-Cho, Yoshida-gun, Fukui, 910-1193, Japan.
| | - Takaya Taira
- Functional Anatomy and Neuroscience, Nagoya University Graduate School of Medicine, 65 Tsurumai, Showa-Ku, Nagoya, Aichi, 466-8550, Japan
| | - Yuma Iio
- Functional Anatomy and Neuroscience, Nagoya University Graduate School of Medicine, 65 Tsurumai, Showa-Ku, Nagoya, Aichi, 466-8550, Japan
| | - Akinobu Kawamura
- Functional Anatomy and Neuroscience, Nagoya University Graduate School of Medicine, 65 Tsurumai, Showa-Ku, Nagoya, Aichi, 466-8550, Japan
| | - Ayusa Kunogi
- Functional Anatomy and Neuroscience, Nagoya University Graduate School of Medicine, 65 Tsurumai, Showa-Ku, Nagoya, Aichi, 466-8550, Japan
| | - Yuka Mizutani
- Functional Anatomy and Neuroscience, Nagoya University Graduate School of Medicine, 65 Tsurumai, Showa-Ku, Nagoya, Aichi, 466-8550, Japan
| | - Hiroshi Kiyama
- Functional Anatomy and Neuroscience, Nagoya University Graduate School of Medicine, 65 Tsurumai, Showa-Ku, Nagoya, Aichi, 466-8550, Japan.
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4
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Sun S, Zhao G, Jia M, Jiang Q, Li S, Wang H, Li W, Wang Y, Bian X, Zhao YG, Huang X, Yang G, Cai H, Pastor-Pareja JC, Ge L, Zhang C, Hu J. Stay in touch with the endoplasmic reticulum. SCIENCE CHINA. LIFE SCIENCES 2024; 67:230-257. [PMID: 38212460 DOI: 10.1007/s11427-023-2443-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/19/2023] [Accepted: 08/28/2023] [Indexed: 01/13/2024]
Abstract
The endoplasmic reticulum (ER), which is composed of a continuous network of tubules and sheets, forms the most widely distributed membrane system in eukaryotic cells. As a result, it engages a variety of organelles by establishing membrane contact sites (MCSs). These contacts regulate organelle positioning and remodeling, including fusion and fission, facilitate precise lipid exchange, and couple vital signaling events. Here, we systematically review recent advances and converging themes on ER-involved organellar contact. The molecular basis, cellular influence, and potential physiological functions for ER/nuclear envelope contacts with mitochondria, Golgi, endosomes, lysosomes, lipid droplets, autophagosomes, and plasma membrane are summarized.
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Affiliation(s)
- Sha Sun
- National Laboratory of Biomacromolecules, Institute of Biophysics, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Beijing, 100101, China
| | - Gan Zhao
- The Ministry of Education Key Laboratory of Cell Proliferation and Differentiation, College of Life Sciences, Peking University, Beijing, 100871, China
| | - Mingkang Jia
- The Ministry of Education Key Laboratory of Cell Proliferation and Differentiation, College of Life Sciences, Peking University, Beijing, 100871, China
| | - Qing Jiang
- The Ministry of Education Key Laboratory of Cell Proliferation and Differentiation, College of Life Sciences, Peking University, Beijing, 100871, China
| | - Shulin Li
- State Key Laboratory of Membrane Biology, Tsinghua-Peking Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing, 100084, China
| | - Haibin Wang
- National Laboratory of Biomacromolecules, Institute of Biophysics, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Beijing, 100101, China
| | - Wenjing Li
- Laboratory of Computational Biology & Machine Intelligence, School of Artificial Intelligence, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Yunyun Wang
- State Key Laboratory of Medicinal Chemical Biology, College of Life Sciences, Nankai University, Tianjin, 300071, China
| | - Xin Bian
- State Key Laboratory of Medicinal Chemical Biology, College of Life Sciences, Nankai University, Tianjin, 300071, China.
| | - Yan G Zhao
- Brain Research Center, Department of Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen, 518055, China.
| | - Xun Huang
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Innovation Academy for Seed Design, Chinese Academy of Sciences, Beijing, 100101, China.
| | - Ge Yang
- Laboratory of Computational Biology & Machine Intelligence, School of Artificial Intelligence, University of Chinese Academy of Sciences, Beijing, 100049, China.
| | - Huaqing Cai
- National Laboratory of Biomacromolecules, Institute of Biophysics, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Beijing, 100101, China.
| | - Jose C Pastor-Pareja
- State Key Laboratory of Membrane Biology, Tsinghua-Peking Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing, 100084, China.
- Institute of Neurosciences, Consejo Superior de Investigaciones Cientfflcas-Universidad Miguel Hernandez, San Juan de Alicante, 03550, Spain.
| | - Liang Ge
- State Key Laboratory of Membrane Biology, Tsinghua-Peking Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing, 100084, China.
| | - Chuanmao Zhang
- The Ministry of Education Key Laboratory of Cell Proliferation and Differentiation, College of Life Sciences, Peking University, Beijing, 100871, China.
| | - Junjie Hu
- National Laboratory of Biomacromolecules, Institute of Biophysics, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Beijing, 100101, China.
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5
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Yu B, Liu J, Cai Z, Mu T, Zhang D, Feng X, Gu Y, Zhang J. MicroRNA-19a regulates milk fat metabolism by targeting SYT1 in bovine mammary epithelial cells. Int J Biol Macromol 2023; 253:127096. [PMID: 37769766 DOI: 10.1016/j.ijbiomac.2023.127096] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2023] [Revised: 09/24/2023] [Accepted: 09/24/2023] [Indexed: 10/03/2023]
Abstract
MicroRNAs (miRNAs) are important post-transcriptional factors involved in the regulation of gene expression and play crucial roles in biological processes related to milk fat metabolism. Our previous study revealed that miR-19a expression was significantly higher in the mammary epithelial cells of high-milk fat cows than in those of low-milk fat cows. However, the precise molecular mechanisms underlying these differences remain unclear. In this study, we found a high expression of miR-19a in the mammary tissues of dairy cows. The regulatory effects of miR-19a on bovine mammary epithelial cells (BMECs) were analyzed using cell counting kit-8 and 5-ethynyl-2'-deoxyuridine assays, which demonstrated that miR-19a significantly inhibited BMEC proliferation. Transfection of the miR-19a mimic into BMECs significantly upregulated the expression of milk fat marker genes LPL, SCAP, and SREBP1, promoting triglyceride (TG) synthesis and lipid droplet formation, whereas the miR-19a inhibitor exhibited the opposite function. TargetScan and miRWalk predictions revealed that synaptotagmin 1 (SYT1) is a target gene of miR-19a. A dual luciferase reporter gene assay, RT-qPCR, and western blot analyses revealed that miR-19a directly targets the 3'-untranslated region (UTR) of SYT1 and negatively regulates SYT1 expression. Functional validation revealed that overexpression of SYT1 in BMECs significantly downregulated the expression of LPL, SCAP, and SREBP1, and inhibited TG synthesis and lipid droplet formation. Conversely, the knockdown of SYT1 had the opposite effect. Altogether, miR-19a plays a crucial role in regulating the proliferation and differentiation of BMECs and regulates biological processes related to TG synthesis and lipid droplet formation by suppressing SYT1 expression. These findings provide a strong foundation for further research on the functional mechanisms underlying milk fat metabolism in dairy cows.
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Affiliation(s)
- Baojun Yu
- College of Animal Science and Technology, Ningxia University, Yinchuan 750021, China; Key Laboratory of Ruminant Molecular Cell Breeding in Ningxia, Ningxia University, Yinchuan 750021, China
| | - Jiamin Liu
- College of Animal Science and Technology, Ningxia University, Yinchuan 750021, China; Key Laboratory of Ruminant Molecular Cell Breeding in Ningxia, Ningxia University, Yinchuan 750021, China
| | - Zhengyun Cai
- College of Animal Science and Technology, Ningxia University, Yinchuan 750021, China; Key Laboratory of Ruminant Molecular Cell Breeding in Ningxia, Ningxia University, Yinchuan 750021, China
| | - Tong Mu
- School of Life Sciences, Yan'an University, Yan'an 716000, China
| | - Di Zhang
- College of Animal Science and Technology, Ningxia University, Yinchuan 750021, China; Key Laboratory of Ruminant Molecular Cell Breeding in Ningxia, Ningxia University, Yinchuan 750021, China
| | - Xiaofang Feng
- College of Animal Science and Technology, Ningxia University, Yinchuan 750021, China; Key Laboratory of Ruminant Molecular Cell Breeding in Ningxia, Ningxia University, Yinchuan 750021, China
| | - Yaling Gu
- College of Animal Science and Technology, Ningxia University, Yinchuan 750021, China; Key Laboratory of Ruminant Molecular Cell Breeding in Ningxia, Ningxia University, Yinchuan 750021, China
| | - Juan Zhang
- College of Animal Science and Technology, Ningxia University, Yinchuan 750021, China; Key Laboratory of Ruminant Molecular Cell Breeding in Ningxia, Ningxia University, Yinchuan 750021, China.
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6
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Benitez-Fuente F, Botella MA. Biological roles of plant synaptotagmins. Eur J Cell Biol 2023; 102:151335. [PMID: 37390668 DOI: 10.1016/j.ejcb.2023.151335] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2023] [Revised: 06/19/2023] [Accepted: 06/19/2023] [Indexed: 07/02/2023] Open
Abstract
Plant synaptotagmins (SYTs) are resident proteins of the endoplasmic reticulum (ER). They are characterized by an N-terminal transmembrane region and C2 domains at the C-terminus, which tether the ER to the plasma membrane (PM). In addition to their tethering role, SYTs contain a lipid-harboring SMP domain, essential for shuttling lipids between the ER and the PM. There is now abundant literature on Arabidopsis SYT1, the best-characterized family member, which link it to biotic and abiotic responses as well as to ER morphology. Here, we review the current knowledge of SYT members, focusing on their role in stress, and discuss how these roles can be related to their tethering and lipid transport functions. Finally, we contextualize this information about SYTs with their homologs, the yeast tricalbins and the mammalian extended synaptotagmins.
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Affiliation(s)
- Francisco Benitez-Fuente
- Departamento de Biología Molecular y Bioquímica, Instituto de Hortofruticultura Subtropical y Mediterránea "La Mayora", Universidad de Málaga, Consejo Superior de Investigaciones Científicas (IHSM-UMA-CSIC), Universidad de Málaga, Málaga 12907, Spain
| | - Miguel A Botella
- Departamento de Biología Molecular y Bioquímica, Instituto de Hortofruticultura Subtropical y Mediterránea "La Mayora", Universidad de Málaga, Consejo Superior de Investigaciones Científicas (IHSM-UMA-CSIC), Universidad de Málaga, Málaga 12907, Spain.
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7
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Ma Y, Zhao R, Guo H, Tong Q, Langdon WY, Liu W, Zhang J, Zhang J. Cytosolic LPS-induced caspase-11 oligomerization and activation is regulated by extended synaptotagmin 1. Cell Rep 2023; 42:112726. [PMID: 37393619 PMCID: PMC10528594 DOI: 10.1016/j.celrep.2023.112726] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Revised: 05/16/2023] [Accepted: 06/14/2023] [Indexed: 07/04/2023] Open
Abstract
Caspase-11 (Casp-11) is known to induce pyroptosis and defends against cytosol-invading bacterial pathogens, but its regulation remains poorly defined. Here, we identified extended synaptotagmin 1 (E-Syt1), an endoplasmic reticulum protein, as a key regulator of Casp-11 oligomerization and activation. Macrophages lacking E-Syt1 exhibited reduced production of interleukin-1β (IL-1β) and impaired pyroptosis upon cytosolic lipopolysaccharide (LPS) delivery and cytosol-invasive bacterial infection. Moreover, cleavage of Casp-11 and its downstream substrate gasdermin D were significantly diminished in ESyt1-/- macrophages. Upon LPS stimulation, E-Syt1 underwent oligomerization and bound to the p30 domain of Casp-11 via its synaptotagmin-like mitochondrial lipid-binding protein (SMP) domain. E-Syt1 oligomerization and its interaction with Casp-11 facilitated Casp-11 oligomerization and activation. Notably, ESyt1-/- mice were susceptible to infection by cytosol-invading bacteria Burkholderia thailandensis while being resistant to LPS-induced endotoxemia. These findings collectively suggest that E-Syt1 may serve as a platform for Casp-11 oligomerization and activation upon cytosolic LPS sensing.
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Affiliation(s)
- Yilei Ma
- Department of Clinical Laboratory, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, P.R. China; Department of Pathology, The University of Iowa Roy J. and Lucille A. Carver College of Medicine, Iowa City, IA 52242, USA; Key Laboratory of Precision Medicine in Diagnosis and Monitoring Research of Zhejiang Province, Hangzhou, Zhejiang, P.R. China.
| | - Ru Zhao
- Department of Clinical Laboratory, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, P.R. China; Key Laboratory of Precision Medicine in Diagnosis and Monitoring Research of Zhejiang Province, Hangzhou, Zhejiang, P.R. China
| | - Hui Guo
- Department of Pathology, The University of Iowa Roy J. and Lucille A. Carver College of Medicine, Iowa City, IA 52242, USA
| | - Qingchao Tong
- Department of Clinical Laboratory, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, P.R. China; Key Laboratory of Precision Medicine in Diagnosis and Monitoring Research of Zhejiang Province, Hangzhou, Zhejiang, P.R. China
| | - Wallace Y Langdon
- School of Biomedical Sciences, University of Western Australia, Perth, WA, Australia
| | - Weiwei Liu
- Department of Inflammation and Immunity, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44106, USA
| | - Jun Zhang
- Department of Clinical Laboratory, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, P.R. China; Key Laboratory of Precision Medicine in Diagnosis and Monitoring Research of Zhejiang Province, Hangzhou, Zhejiang, P.R. China.
| | - Jian Zhang
- Department of Pathology, The University of Iowa Roy J. and Lucille A. Carver College of Medicine, Iowa City, IA 52242, USA.
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8
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Del Vecchio M, Amado L, Cogan AP, Meert E, Rosseels J, Franssens V, Govers SK, Winderickx J, Montoro AG. Multiple tethers of organelle contact sites are involved in α-synuclein toxicity in yeast. Mol Biol Cell 2023; 34:ar84. [PMID: 37074954 PMCID: PMC10398879 DOI: 10.1091/mbc.e23-01-0029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Revised: 04/05/2023] [Accepted: 04/12/2023] [Indexed: 04/20/2023] Open
Abstract
The protein α-synuclein (α-syn) is one of the major factors linked to Parkinson's disease, yet how its misfolding and deposition contribute to the pathology remains largely elusive. Recently, contact sites among organelles were implicated in the development of this disease. Here, we used the budding yeast Saccharomyces cerevisiae, in which organelle contact sites have been characterized extensively, as a model to investigate their role in α-syn cytotoxicity. We observed that lack of specific tethers that anchor the endoplasmic reticulum to the plasma membrane resulted in cells with increased resistance to α-syn expression. Additionally, we found that strains lacking two dual-function proteins involved in contact sites, Mdm10 and Vps39, were resistant to the expression of α-syn. In the case of Mdm10, we found that this is related to its function in mitochondrial protein biogenesis and not to its role as a contact site tether. In contrast, both functions of Vps39, in vesicular transport and as a tether of the vacuole-mitochondria contact site, were required to support α-syn toxicity. Overall, our findings support that interorganelle communication through membrane contact sites is highly relevant for α-syn-mediated toxicity.
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Affiliation(s)
- Mara Del Vecchio
- Department of Biology, Functional Biology Laboratory, KU Leuven, 3001 Heverlee, Belgium
- Department of Biology, Microbial Systems Cell Biology Laboratory, KU Leuven, 3001 Heverlee, Belgium
| | - Lucia Amado
- Department of Biology/Chemistry, Cellular Communication Laboratory, Osnabrück University, 49076 Osnabrück, Germany
| | - Alexandra P. Cogan
- Department of Biology/Chemistry, Cellular Communication Laboratory, Osnabrück University, 49076 Osnabrück, Germany
| | - Els Meert
- Department of Biology, Functional Biology Laboratory, KU Leuven, 3001 Heverlee, Belgium
| | - Joelle Rosseels
- Department of Biology, Functional Biology Laboratory, KU Leuven, 3001 Heverlee, Belgium
| | - Vanessa Franssens
- Department of Biology, Functional Biology Laboratory, KU Leuven, 3001 Heverlee, Belgium
| | - Sander K. Govers
- Department of Biology, Microbial Systems Cell Biology Laboratory, KU Leuven, 3001 Heverlee, Belgium
| | - Joris Winderickx
- Department of Biology, Functional Biology Laboratory, KU Leuven, 3001 Heverlee, Belgium
| | - Ayelén González Montoro
- Department of Biology/Chemistry, Cellular Communication Laboratory, Osnabrück University, 49076 Osnabrück, Germany
- Center of Cellular Nanoanalytics Osnabrück, 49076 Osnabrück, Germany
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9
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Wang Y, Li Z, Wang X, Zhao Z, Jiao L, Liu R, Wang K, Ma R, Yang Y, Chen G, Wang Y, Bian X. Insights into membrane association of the SMP domain of extended synaptotagmin. Nat Commun 2023; 14:1504. [PMID: 36932127 PMCID: PMC10023780 DOI: 10.1038/s41467-023-37202-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2022] [Accepted: 03/06/2023] [Indexed: 03/19/2023] Open
Abstract
The Synaptotagmin-like Mitochondrial-lipid-binding Protein (SMP) domain is a newly identified lipid transfer module present in proteins that regulate lipid homeostasis at membrane contact sites (MCSs). However, how the SMP domain associates with the membrane to extract and unload lipids is unclear. Here, we performed in vitro DNA brick-assisted lipid transfer assays and in silico molecular dynamics simulations to investigate the molecular basis of the membrane association by the SMP domain of extended synaptotagmin (E-Syt), which tethers the tubular endoplasmic reticulum (ER) to the plasma membrane (PM). We demonstrate that the SMP domain uses its tip region to recognize the extremely curved subdomain of tubular ER and the acidic-lipid-enriched PM for highly efficient lipid transfer. Supporting these findings, disruption of these mechanisms results in a defect in autophagosome biogenesis contributed by E-Syt. Our results suggest a model that provides a coherent picture of the action of the SMP domain at MCSs.
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Affiliation(s)
- Yunyun Wang
- State Key Laboratory of Medicinal Chemical Biology, College of Life Sciences, Frontiers Science Center for Cell Responses, Nankai University, Tianjin, China
| | - Zhenni Li
- State Key Laboratory of Medicinal Chemical Biology, College of Life Sciences, Frontiers Science Center for Cell Responses, Nankai University, Tianjin, China
| | - Xinyu Wang
- College of Life Sciences, Nankai University, Tianjin, China
| | - Ziyuan Zhao
- College of Life Sciences, Nankai University, Tianjin, China
| | - Li Jiao
- College of Life Sciences, Nankai University, Tianjin, China
| | - Ruming Liu
- College of Life Sciences, Nankai University, Tianjin, China
| | - Keying Wang
- College of Life Sciences, Zhejiang University, Hangzhou, China
| | - Rui Ma
- College of Physical Science and Technology, Xiamen University, Xiamen, China
| | - Yang Yang
- Institute of Molecular Medicine, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Guo Chen
- State Key Laboratory of Medicinal Chemical Biology, College of Life Sciences, Frontiers Science Center for Cell Responses, Nankai University, Tianjin, China
| | - Yong Wang
- College of Life Sciences, Zhejiang University, Hangzhou, China.
- The Provincial International Science and Technology Cooperation Base on Engineering Biology, International Campus of Zhejiang University, Haining, China.
| | - Xin Bian
- State Key Laboratory of Medicinal Chemical Biology, College of Life Sciences, Frontiers Science Center for Cell Responses, Nankai University, Tianjin, China.
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10
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He R, Liu F, Wang H, Huang S, Xu K, Zhang C, Liu Y, Yu H. ORP9 and ORP10 form a heterocomplex to transfer phosphatidylinositol 4-phosphate at ER-TGN contact sites. Cell Mol Life Sci 2023; 80:77. [PMID: 36853333 PMCID: PMC11072704 DOI: 10.1007/s00018-023-04728-5] [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: 10/17/2022] [Revised: 02/15/2023] [Accepted: 02/15/2023] [Indexed: 03/01/2023]
Abstract
Oxysterol-binding protein (OSBP) and its related proteins (ORPs) are a family of lipid transfer proteins (LTPs) that mediate non-vesicular lipid transport. ORP9 and ORP10, members of the OSBP/ORPs family, are located at the endoplasmic reticulum (ER)-trans-Golgi network (TGN) membrane contact sites (MCSs). It remained unclear how they mediate lipid transport. In this work, we discovered that ORP9 and ORP10 form a binary complex through intermolecular coiled-coil (CC) domain-CC domain interaction. The PH domains of ORP9 and ORP10 specially interact with phosphatidylinositol 4-phosphate (PI4P), mediating the TGN targeting. The ORP9-ORP10 complex plays a critical role in regulating PI4P levels at the TGN. Using in vitro reconstitution assays, we observed that while full-length ORP9 efficiently transferred PI4P between two apposed membranes, the lipid transfer kinetics was further accelerated by ORP10. Interestingly, our data showed that the PH domains of ORP9 and ORP10 participate in membrane tethering simultaneously, whereas ORDs of both ORP9 and ORP10 are required for lipid transport. Furthermore, our data showed that the depletion of ORP9 and ORP10 led to increased vesicle transport to the plasma membrane (PM). These findings demonstrate that ORP9 and ORP10 form a binary complex through the CC domains, maintaining PI4P homeostasis at ER-TGN MCSs and regulating vesicle trafficking.
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Affiliation(s)
- Ruyue He
- Jiangsu Key Laboratory for Molecular and Medical Biotechnology, College of Life Sciences, Nanjing Normal University, Nanjing, 210023, China
| | - Furong Liu
- Jiangsu Key Laboratory for Molecular and Medical Biotechnology, College of Life Sciences, Nanjing Normal University, Nanjing, 210023, China
| | - Hui Wang
- Jiangsu Key Laboratory for Molecular and Medical Biotechnology, College of Life Sciences, Nanjing Normal University, Nanjing, 210023, China
| | - Shuai Huang
- Jiangsu Key Laboratory for Molecular and Medical Biotechnology, College of Life Sciences, Nanjing Normal University, Nanjing, 210023, China
| | - Kai Xu
- Jiangsu Key Laboratory for Microbes and Functional Genomics, College of Life Sciences, Nanjing Normal University, Nanjing, 210023, China
| | - Conggang Zhang
- School of Pharmaceutical Sciences, Tsinghua University, Beijing, China
- Tsinghua-Peking Center for Life Sciences, Beijing, China
| | - Yinghui Liu
- Jiangsu Key Laboratory for Molecular and Medical Biotechnology, College of Life Sciences, Nanjing Normal University, Nanjing, 210023, China.
| | - Haijia Yu
- Jiangsu Key Laboratory for Molecular and Medical Biotechnology, College of Life Sciences, Nanjing Normal University, Nanjing, 210023, China.
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11
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Mao R, Tong C, Liu JJ. E-Syt1 Regulates Neuronal Activity-Dependent Endoplasmic Reticulum-Plasma Membrane Junctions and Surface Expression of AMPA Receptors. CONTACT (THOUSAND OAKS (VENTURA COUNTY, CALIF.)) 2023; 6:25152564231185011. [PMID: 37484831 PMCID: PMC10359807 DOI: 10.1177/25152564231185011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/22/2022] [Revised: 06/05/2023] [Accepted: 06/12/2023] [Indexed: 07/25/2023]
Abstract
Endoplasmic reticulum (ER)-plasma membrane (PM) contact sites/junctions play important roles in cell physiology including signal transduction, ion and lipid transfer, and membrane dynamics. However, little is known about the dynamic regulation and functional roles of ER-PM junctions in neurons. Using a split green fluorescent protein-based membrane contact probe, we find that the density of ER-PM contact sites changes dynamically in the dendrites of hippocampal neurons undergoing long-term synaptic potentiation (LTP). We show that the Ca2±-sensing membrane tethering protein Extended Synaptotagmin 1 (E-Syt1) mediates the formation of ER-PM contact sites during LTP. We also show that E-Syt1 is required for neuronal activity-dependent surface expression of the α-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid-type glutamate receptors. These findings implicate ER-PM junctions in the regulation of neurotransmitter receptor trafficking and synaptic plasticity.
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Affiliation(s)
- Ranran Mao
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China
- College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Chunfang Tong
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China
| | - Jia-Jia Liu
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China
- College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China
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12
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Clausmeyer L, Fröhlich F. Mechanisms of Nonvesicular Ceramide Transport. CONTACT (THOUSAND OAKS (VENTURA COUNTY, CALIF.)) 2023; 6:25152564231208250. [PMID: 37859671 PMCID: PMC10583516 DOI: 10.1177/25152564231208250] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/09/2023] [Revised: 09/29/2023] [Accepted: 09/29/2023] [Indexed: 10/21/2023]
Abstract
Ceramides, as key components of cellular membranes, play essential roles in various cellular processes, including apoptosis, cell proliferation, and cell signaling. Ceramides are the precursors of all complex sphingolipids in eukaryotic cells. They are synthesized in the endoplasmic reticulum and are further processed at the Golgi apparatus. Therefore, ceramides have to be transported between these two organelles. In mammalian cells, the ceramide transfer protein forms a contact site between the ER and the trans-Golgi region and transports ceramide utilizing its steroidogenic acute regulatory protein-related lipid transfer domain. In yeast, multiple mechanisms of nonvesicular ceramide transport have been described. This involves the nuclear-vacuolar junction protein Nvj2, the yeast tricalbin proteins, and the lipocalin-like protein Svf1. This review aims to provide a comprehensive overview of nonvesicular ceramide transport mechanisms and their relevance in cellular physiology. We will highlight the physiological and pathological consequences of perturbations in nonvesicular ceramide transport and discuss future challenges in identifying and analyzing ceramide transfer proteins.
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Affiliation(s)
- Lena Clausmeyer
- Department of Biology/Chemistry, Bioanalytical Chemistry Section, Osnabrück University, Osnabrück, Germany
| | - Florian Fröhlich
- Department of Biology/Chemistry, Bioanalytical Chemistry Section, Osnabrück University, Osnabrück, Germany
- Center of Cellular Nanoanalytics Osnabrück (CellNanOs), Osnabrück University, Osnabrück, Germany
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13
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Sandes JM, de Figueiredo RCBQ. The endoplasmic reticulum of trypanosomatids: An unrevealed road for chemotherapy. Front Cell Infect Microbiol 2022; 12:1057774. [PMID: 36439218 PMCID: PMC9684732 DOI: 10.3389/fcimb.2022.1057774] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2022] [Accepted: 10/24/2022] [Indexed: 01/04/2024] Open
Abstract
The endoplasmic reticulum (ER) of higher eukaryotic cells forms an intricate membranous network that serves as the main processing facility for folding and assembling of secreted and membrane proteins. The ER is a highly dynamic organelle that interacts with other intracellular structures, as well as endosymbiotic pathogenic and non-pathogenic microorganisms. A strict ER quality control (ERQC) must work to ensure that proteins entering the ER are folded and processed correctly. Unfolded or misfolded proteins are usually identified, selected, and addressed to Endoplasmic Reticulum-Associated Degradation (ERAD) complex. Conversely, when there is a large demand for secreted proteins or ER imbalance, the accumulation of unfolded or misfolded proteins activates the Unfold Protein Response (UPR) to restore the ER homeostasis or, in the case of persistent ER stress, induces the cell death. Pathogenic trypanosomatids, such as Trypanosoma cruzi, Trypanosoma brucei and Leishmania spp are the etiological agents of important neglected diseases. These protozoans have a complex life cycle alternating between vertebrate and invertebrate hosts. The ER of trypanosomatids, like those found in higher eukaryotes, is also specialized for secretion, and depends on the ERAD and non-canonical UPR to deal with the ER stress. Here, we reviewed the basic aspects of ER biology, organization, and quality control in trypanosomatids. We also focused on the unusual way by which T. cruzi, T. brucei, and Leishmania spp. respond to ER stress, emphasizing how these parasites' ER-unrevealed roads might be an attractive target for chemotherapy.
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Affiliation(s)
- Jana Messias Sandes
- Laboratório de Biologia Celular e Molecular de Patógenos, Departamento de Microbiologia, Instituto Aggeu Magalhães, Recife, Brazil
- Laboratório de Microscopia Eletrônica, Instituto Keizo Assami, Universidade Federal de Pernambuco, Recife, Brazil
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14
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Zhang Y, Ge J, Bian X, Kumar A. Quantitative Models of Lipid Transfer and Membrane Contact Formation. CONTACT (THOUSAND OAKS (VENTURA COUNTY, CALIF.)) 2022; 5:1-21. [PMID: 36120532 DOI: 10.1177/25152564221096024] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Lipid transfer proteins (LTPs) transfer lipids between different organelles, and thus play key roles in lipid homeostasis and organelle dynamics. The lipid transfer often occurs at the membrane contact sites (MCS) where two membranes are held within 10-30 nm. While most LTPs act as a shuttle to transfer lipids, recent experiments reveal a new category of eukaryotic LTPs that may serve as a bridge to transport lipids in bulk at MCSs. However, the molecular mechanisms underlying lipid transfer and MCS formation are not well understood. Here, we first review two recent studies of extended synaptotagmin (E-Syt)-mediated membrane binding and lipid transfer using novel approaches. Then we describe mathematical models to quantify the kinetics of lipid transfer by shuttle LTPs based on a lipid exchange mechanism. We find that simple lipid mixing among membranes of similar composition and/or lipid partitioning among membranes of distinct composition can explain lipid transfer against a concentration gradient widely observed for LTPs. We predict that selective transport of lipids, but not membrane proteins, by bridge LTPs leads to osmotic membrane tension by analogy to the osmotic pressure across a semipermeable membrane. A gradient of such tension and the conventional membrane tension may drive bulk lipid flow through bridge LTPs at a speed consistent with the fast membrane expansion observed in vivo. Finally, we discuss the implications of membrane tension and lipid transfer in organelle biogenesis. Overall, the quantitative models may help clarify the mechanisms of LTP-mediated MCS formation and lipid transfer.
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Affiliation(s)
- Yongli Zhang
- Department of Cell Biology, Yale University School of Medicine, New Haven, CT, USA.,Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT, USA
| | - Jinghua Ge
- Department of Cell Biology, Yale University School of Medicine, New Haven, CT, USA
| | - Xin Bian
- Department of Cell Biology, Yale University School of Medicine, New Haven, CT, USA.,Department of Neuroscience, Yale University School of Medicine, New Haven, CT, USA.,Present address: State Key Laboratory of Medicinal Chemical Biology, College of Life Sciences, Nankai University, Tianjin, China
| | - Avinash Kumar
- Department of Cell Biology, Yale University School of Medicine, New Haven, CT, USA
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15
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Ashraf APK, Gerke V. The resealing factor S100A11 interacts with annexins and extended synaptotagmin-1 in the course of plasma membrane wound repair. Front Cell Dev Biol 2022; 10:968164. [PMID: 36200035 PMCID: PMC9527316 DOI: 10.3389/fcell.2022.968164] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2022] [Accepted: 09/01/2022] [Indexed: 11/13/2022] Open
Abstract
After damage, cells repair their plasma membrane in an active process that is driven by Ca2+ entering through the wound. This triggers a range of Ca2+-regulated events such as the translocation of different Ca2+-binding proteins to the wound site which likely function in the repair process. The translocated proteins include Ca2+/phospholipid binding proteins of the annexin (ANX) family and S100A11, an EF hand-type Ca2+-binding protein which can interact with ANX. The molecular mechanism by which S100A11 mediates PM wound repair remains poorly understood although it likely involves interactions with ANX. Here, using S100A11 knockout endothelial cells and expression of S100A11 mutants, we show that endothelial S100A11 is essential for efficient plasma membrane wound repair and engages in Ca2+-dependent interactions with ANXA1 and ANXA2 through its C-terminal extension (residues 93–105). ANXA2 but not ANXA1 translocation to the wound is substantially inhibited in the absence of S100A11; however, the repair defect in S100A11 knockout cells is rescued by ectopic expression of an ANX interaction-defective S100A11 mutant, suggesting an ANX-independent role of S100A11 in membrane wound repair. In search for other interaction partners that could mediate this action of S100A11 we identify extended synaptotagmin 1 (E-Syt1), a protein tether that regulates endoplasmic reticulum-plasma membrane contact sites. E-Syt1 binds to S100A11 in the presence of Ca2+ and depletion of E-Syt1 interferes with wound site recruitment of S100A11 and proper membrane resealing. Thus, the role of S100A11 in membrane wound repair does not exclusively dependent on ANX interactions and a Ca2+-regulated S100A11-E-Syt1 complex acts as a yet unrecognized component of the membrane resealing machinery.
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16
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Sargsyan Y, Kalinowski J, Thoms S. Calcium in peroxisomes: An essential messenger in an essential cell organelle. Front Cell Dev Biol 2022; 10:992235. [PMID: 36111338 PMCID: PMC9468670 DOI: 10.3389/fcell.2022.992235] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2022] [Accepted: 08/10/2022] [Indexed: 11/17/2022] Open
Abstract
Calcium is a central signal transduction element in biology. Peroxisomes are essential cellular organelles, yet calcium handling in peroxisomes has been contentious. Recent advances show that peroxisomes are part of calcium homeostasis in cardiac myocytes and therefore may contribute to or even shape their calcium-dependent functionality. However, the mechanisms of calcium movement between peroxisomes and other cellular sites and their mediators remain elusive. Here, we review calcium handling in peroxisomes in concert with other organelles and summarize the most recent knowledge on peroxisomal involvement in calcium dynamics with a focus on mammalian cells.
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Affiliation(s)
- Yelena Sargsyan
- Department for Biochemistry and Molecular Medicine, Medical School EWL, Bielefeld University, Bielefeld, Germany
- Department of Child and Adolescent Health, University Medical Center, Göttingen, Germany
| | - Julia Kalinowski
- Department for Biochemistry and Molecular Medicine, Medical School EWL, Bielefeld University, Bielefeld, Germany
| | - Sven Thoms
- Department for Biochemistry and Molecular Medicine, Medical School EWL, Bielefeld University, Bielefeld, Germany
- Department of Child and Adolescent Health, University Medical Center, Göttingen, Germany
- German Center for Cardiovascular Research (DZHK), Partner Site Göttingen, Göttingen, Germany
- *Correspondence: Sven Thoms,
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17
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Pourshafie N, Masati E, Lopez A, Bunker E, Snyder A, Edwards NA, Winkelsas AM, Fischbeck KH, Grunseich C. Altered SYNJ2BP-mediated mitochondrial-ER contacts in motor neuron disease. Neurobiol Dis 2022; 172:105832. [PMID: 35907632 DOI: 10.1016/j.nbd.2022.105832] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2022] [Revised: 07/01/2022] [Accepted: 07/22/2022] [Indexed: 11/30/2022] Open
Abstract
Synaptojanin 2 binding protein (SYNJ2BP) is an outer mitochondrial membrane protein with a cytosolic PDZ domain that functions as a cellular signaling hub. Few studies have evaluated its role in disease. Here we use induced pluripotent stem cell (iPSC)-derived motor neurons and post-mortem tissue from patients with two hereditary motor neuron diseases, spinal and bulbar muscular atrophy (SBMA) and amyotrophic lateral sclerosis type 4 (ALS4), and show that SYNJ2BP expression is increased in diseased motor neurons. Similarly, we show that SYNJ2BP expression increases in iPSC-derived motor neurons undergoing stress. Using proteomic analysis, we found that elevated SYNJ2BP alters the cellular distribution of mitochondria and increases mitochondrial-ER membrane contact sites. Furthermore, decreasing SYNJ2BP levels improves mitochondrial oxidative function in the diseased motor neurons. Together, our observations offer new insight into the molecular pathology of motor neuron disease and the role of SYNJ2BP in mitochondrial dysfunction.
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Affiliation(s)
- Naemeh Pourshafie
- Neurogenetics Branch, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, USA.
| | - Ester Masati
- Neurogenetics Branch, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, USA.
| | - Amber Lopez
- Neurogenetics Branch, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, USA
| | - Eric Bunker
- Surgical Neurology Branch, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, USA.
| | - Allison Snyder
- Neurogenetics Branch, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, USA.
| | - Nancy A Edwards
- Surgical Neurology Branch, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, USA.
| | - Audrey M Winkelsas
- Neurogenetics Branch, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, USA.
| | - Kenneth H Fischbeck
- Neurogenetics Branch, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, USA.
| | - Christopher Grunseich
- Neurogenetics Branch, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, USA.
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18
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Krawczyk HE, Sun S, Doner NM, Yan Q, Lim MSS, Scholz P, Niemeyer PW, Schmitt K, Valerius O, Pleskot R, Hillmer S, Braus GH, Wiermer M, Mullen RT, Ischebeck T. SEED LIPID DROPLET PROTEIN1, SEED LIPID DROPLET PROTEIN2, and LIPID DROPLET PLASMA MEMBRANE ADAPTOR mediate lipid droplet-plasma membrane tethering. THE PLANT CELL 2022; 34:2424-2448. [PMID: 35348751 PMCID: PMC9134073 DOI: 10.1093/plcell/koac095] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/13/2022] [Accepted: 02/14/2022] [Indexed: 05/27/2023]
Abstract
Membrane contact sites (MCSs) are interorganellar connections that allow for the direct exchange of molecules, such as lipids or Ca2+ between organelles, but can also serve to tether organelles at specific locations within cells. Here, we identified and characterized three proteins of Arabidopsis thaliana that form a lipid droplet (LD)-plasma membrane (PM) tethering complex in plant cells, namely LD-localized SEED LD PROTEIN (SLDP) 1 and SLDP2 and PM-localized LD-PLASMA MEMBRANE ADAPTOR (LIPA). Using proteomics and different protein-protein interaction assays, we show that both SLDPs associate with LIPA. Disruption of either SLDP1 and SLDP2 expression, or that of LIPA, leads to an aberrant clustering of LDs in Arabidopsis seedlings. Ectopic co-expression of one of the SLDPs with LIPA is sufficient to reconstitute LD-PM tethering in Nicotiana tabacum pollen tubes, a cell type characterized by dynamically moving LDs in the cytosolic streaming. Furthermore, confocal laser scanning microscopy revealed both SLDP2.1 and LIPA to be enriched at LD-PM contact sites in seedlings. These and other results suggest that SLDP and LIPA interact to form a tethering complex that anchors a subset of LDs to the PM during post-germinative seedling growth in Arabidopsis.
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Affiliation(s)
- Hannah Elisa Krawczyk
- Albrecht-von-Haller-Institute for Plant Sciences and Göttingen Center for Molecular Biosciences (GZMB), Department of Plant Biochemistry, University of Göttingen, Göttingen, Germany
| | - Siqi Sun
- Albrecht-von-Haller-Institute for Plant Sciences and Göttingen Center for Molecular Biosciences (GZMB), Department of Plant Biochemistry, University of Göttingen, Göttingen, Germany
| | - Nathan M Doner
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, ON N1G 2W1, Canada
| | - Qiqi Yan
- Albrecht-von-Haller-Institute for Plant Sciences and Göttingen Center for Molecular Biosciences (GZMB), Molecular Biology of Plant-Microbe Interactions Research Group, University of Göttingen, Göttingen, Germany
| | - Magdiel Sheng Satha Lim
- Albrecht-von-Haller-Institute for Plant Sciences and Göttingen Center for Molecular Biosciences (GZMB), Department of Plant Biochemistry, University of Göttingen, Göttingen, Germany
| | - Patricia Scholz
- Albrecht-von-Haller-Institute for Plant Sciences and Göttingen Center for Molecular Biosciences (GZMB), Department of Plant Biochemistry, University of Göttingen, Göttingen, Germany
| | - Philipp William Niemeyer
- Albrecht-von-Haller-Institute for Plant Sciences and Göttingen Center for Molecular Biosciences (GZMB), Department of Plant Biochemistry, University of Göttingen, Göttingen, Germany
| | - Kerstin Schmitt
- Institute for Microbiology and Genetics and Göttingen Center for Molecular Biosciences (GZMB) and Service Unit LCMS Protein Analytics, Department for Molecular Microbiology and Genetics, University of Göttingen, Göttingen, Germany
- Göttingen Center for Molecular Biosciences (GZMB), University of Göttingen, Göttingen, Germany
| | - Oliver Valerius
- Institute for Microbiology and Genetics and Göttingen Center for Molecular Biosciences (GZMB) and Service Unit LCMS Protein Analytics, Department for Molecular Microbiology and Genetics, University of Göttingen, Göttingen, Germany
- Göttingen Center for Molecular Biosciences (GZMB), University of Göttingen, Göttingen, Germany
| | - Roman Pleskot
- Institute of Experimental Botany of the Czech Academy of Sciences, Prague, Czech Republic
| | - Stefan Hillmer
- Electron Microscopy Core Facility, Heidelberg University, Heidelberg, Germany
| | - Gerhard H Braus
- Institute for Microbiology and Genetics and Göttingen Center for Molecular Biosciences (GZMB) and Service Unit LCMS Protein Analytics, Department for Molecular Microbiology and Genetics, University of Göttingen, Göttingen, Germany
- Göttingen Center for Molecular Biosciences (GZMB), University of Göttingen, Göttingen, Germany
| | - Marcel Wiermer
- Albrecht-von-Haller-Institute for Plant Sciences and Göttingen Center for Molecular Biosciences (GZMB), Molecular Biology of Plant-Microbe Interactions Research Group, University of Göttingen, Göttingen, Germany
- Göttingen Center for Molecular Biosciences (GZMB), University of Göttingen, Göttingen, Germany
| | - Robert T Mullen
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, ON N1G 2W1, Canada
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19
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Qian T, Li C, Liu F, Xu K, Wan C, Liu Y, Yu H. Arabidopsis synaptotagmin 1 mediates lipid transport in a lipid composition-dependent manner. Traffic 2022; 23:346-356. [PMID: 35451158 DOI: 10.1111/tra.12844] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2021] [Revised: 04/11/2022] [Accepted: 04/15/2022] [Indexed: 11/29/2022]
Abstract
The endoplasmic reticulum (ER) - plasma membrane (PM) contact sites (EPCSs) are structurally conserved in eukaryotes. The Arabidopsis ER-anchored synaptotagmin 1 (SYT1), enriched in EPCSs, plays a critical role in plant abiotic stress tolerance. It has become clear that SYT1 interacts with PM to mediate ER-PM connectivity. However, whether SYT1 performs additional functions at EPCSs remains unknown. Here, we reported that SYT1 efficiently transfers phospholipids between membranes. The lipid transfer activity of SYT1 is highly dependent on PI(4,5)P2 , a signal lipid accumulated at the PM under abiotic stress. Mechanically, while SYT1 transfers lipids fundamentally through the synaptotagmin-like mitochondrial-lipid-binding protein (SMP) domain, the efficient lipid transport requires the C2A domain-mediated membrane tethering. Interestingly, we observed that Ca2+ could stimulate SYT1-mediated lipid transport. In addition to PI(4,5)P2 , the Ca2+ activation requires the phosphatidylserine, another negatively charged lipid on the opposed membrane. Together, our studies identified Arabidopsis SYT1 as a lipid transfer protein at EPCSs and demonstrated it takes conserved as well as divergent mechanisms with other extend-synaptotagmins. The critical role of lipid composition and Ca2+ reveals SYT1-mediated lipid transport is highly regulated by signals in response to abiotic stresses.
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Affiliation(s)
- Tiantian Qian
- Jiangsu Key Laboratory for Molecular and Medical Biotechnology, College of Life Sciences, Nanjing Normal University, Nanjing, China
| | - Chenlu Li
- Jiangsu Key Laboratory for Molecular and Medical Biotechnology, College of Life Sciences, Nanjing Normal University, Nanjing, China
| | - Furong Liu
- Jiangsu Key Laboratory for Molecular and Medical Biotechnology, College of Life Sciences, Nanjing Normal University, Nanjing, China
| | - Kai Xu
- Jiangsu Key Laboratory for Microbes and Functional Genomics, College of Life Sciences, Nanjing Normal University, Nanjing, China
| | - Chun Wan
- Department of Molecular, Cellular and Developmental Biology, University of Colorado, Boulder, CO, USA
| | - Yinghui Liu
- Jiangsu Key Laboratory for Molecular and Medical Biotechnology, College of Life Sciences, Nanjing Normal University, Nanjing, China
| | - Haijia Yu
- Jiangsu Key Laboratory for Molecular and Medical Biotechnology, College of Life Sciences, Nanjing Normal University, Nanjing, China
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20
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Thomas FB, Omnus DJ, Bader JM, Chung GH, Kono N, Stefan CJ. Tricalbin proteins regulate plasma membrane phospholipid homeostasis. Life Sci Alliance 2022; 5:5/8/e202201430. [PMID: 35440494 PMCID: PMC9018018 DOI: 10.26508/lsa.202201430] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Revised: 04/03/2022] [Accepted: 04/04/2022] [Indexed: 12/26/2022] Open
Abstract
The evolutionarily conserved extended synaptotagmin (E-Syt) proteins are calcium-activated lipid transfer proteins that function at contacts between the ER and plasma membrane (ER-PM contacts). However, roles of the E-Syt family members in PM lipid organisation remain incomplete. Among the E-Syt family, the yeast tricalbin (Tcb) proteins are essential for PM integrity upon heat stress, but it is not known how they contribute to PM maintenance. Using quantitative lipidomics and microscopy, we find that the Tcb proteins regulate phosphatidylserine homeostasis at the PM. Moreover, upon heat-induced membrane stress, Tcb3 co-localises with the PM protein Sfk1 that is implicated in PM phospholipid asymmetry and integrity. The Tcb proteins also control the PM targeting of the known phosphatidylserine effector Pkc1 upon heat-induced stress. Phosphatidylserine has evolutionarily conserved roles in PM organisation, integrity, and repair. We propose that phospholipid regulation is an ancient essential function of E-Syt family members required for PM integrity.
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Affiliation(s)
- Ffion B Thomas
- Medical Research Council Laboratory for Molecular Cell Biology, University College London, London, UK
| | - Deike J Omnus
- Medical Research Council Laboratory for Molecular Cell Biology, University College London, London, UK
| | - Jakob M Bader
- Medical Research Council Laboratory for Molecular Cell Biology, University College London, London, UK
| | - Gary Hc Chung
- Medical Research Council Laboratory for Molecular Cell Biology, University College London, London, UK
| | - Nozomu Kono
- Department of Health Chemistry, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo, Japan
| | - Christopher J Stefan
- Medical Research Council Laboratory for Molecular Cell Biology, University College London, London, UK
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21
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Maltan L, Andova AM, Derler I. The Role of Lipids in CRAC Channel Function. Biomolecules 2022; 12:biom12030352. [PMID: 35327543 PMCID: PMC8944985 DOI: 10.3390/biom12030352] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2022] [Revised: 02/12/2022] [Accepted: 02/20/2022] [Indexed: 11/28/2022] Open
Abstract
The composition and dynamics of the lipid membrane define the physical properties of the bilayer and consequently affect the function of the incorporated membrane transporters, which also applies for the prominent Ca2+ release-activated Ca2+ ion channel (CRAC). This channel is activated by receptor-induced Ca2+ store depletion of the endoplasmic reticulum (ER) and consists of two transmembrane proteins, STIM1 and Orai1. STIM1 is anchored in the ER membrane and senses changes in the ER luminal Ca2+ concentration. Orai1 is the Ca2+-selective, pore-forming CRAC channel component located in the plasma membrane (PM). Ca2+ store-depletion of the ER triggers activation of STIM1 proteins, which subsequently leads to a conformational change and oligomerization of STIM1 and its coupling to as well as activation of Orai1 channels at the ER-PM contact sites. Although STIM1 and Orai1 are sufficient for CRAC channel activation, their efficient activation and deactivation is fine-tuned by a variety of lipids and lipid- and/or ER-PM junction-dependent accessory proteins. The underlying mechanisms for lipid-mediated CRAC channel modulation as well as the still open questions, are presented in this review.
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22
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Körner C, Fröhlich F. Compartmentation and functions of sphingolipids. Curr Opin Cell Biol 2022; 74:104-111. [DOI: 10.1016/j.ceb.2022.01.006] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2021] [Revised: 01/13/2022] [Accepted: 01/22/2022] [Indexed: 02/08/2023]
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23
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Tomasello DL, Kim JL, Khodour Y, McCammon JM, Mitalipova M, Jaenisch R, Futerman AH, Sive H. 16pdel lipid changes in iPSC-derived neurons and function of FAM57B in lipid metabolism and synaptogenesis. iScience 2022; 25:103551. [PMID: 34984324 PMCID: PMC8693007 DOI: 10.1016/j.isci.2021.103551] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Revised: 09/23/2021] [Accepted: 11/26/2021] [Indexed: 01/01/2023] Open
Abstract
The complex 16p11.2 deletion syndrome (16pdel) is accompanied by neurological disorders, including epilepsy, autism spectrum disorder, and intellectual disability. We demonstrated that 16pdel iPSC differentiated neurons from affected people show augmented local field potential activity and altered ceramide-related lipid species relative to unaffected. FAM57B, a poorly characterized gene in the 16p11.2 interval, has emerged as a candidate tied to symptomatology. We found that FAM57B modulates ceramide synthase (CerS) activity, but is not a CerS per se. In FAM57B mutant human neuronal cells and zebrafish brain, composition and levels of sphingolipids and glycerolipids associated with cellular membranes are disrupted. Consistently, we observed aberrant plasma membrane architecture and synaptic protein mislocalization, which were accompanied by depressed brain and behavioral activity. Together, these results suggest that haploinsufficiency of FAM57B contributes to changes in neuronal activity and function in 16pdel syndrome through a crucial role for the gene in lipid metabolism.
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Affiliation(s)
| | - Jiyoon L. Kim
- Department of Biomolecular Sciences, Weizmann Institute of Science, Rehovot 76100, Israel
| | - Yara Khodour
- Department of Biomolecular Sciences, Weizmann Institute of Science, Rehovot 76100, Israel
| | | | - Maya Mitalipova
- Whitehead Institute for Biomedical Research, Cambridge, MA 02142, USA
| | - Rudolf Jaenisch
- Whitehead Institute for Biomedical Research, Cambridge, MA 02142, USA
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Anthony H. Futerman
- Department of Biomolecular Sciences, Weizmann Institute of Science, Rehovot 76100, Israel
| | - Hazel Sive
- Whitehead Institute for Biomedical Research, Cambridge, MA 02142, USA
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
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24
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Reconstitution and biochemical studies of extended synaptotagmin-mediated lipid transport. Methods Enzymol 2022; 675:33-62. [DOI: 10.1016/bs.mie.2022.07.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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25
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Ma L, Ge J, Bian X, Zhang Y. Single-Molecule Optical Tweezers Study of Protein-Membrane Interactions. Methods Mol Biol 2022; 2473:367-383. [PMID: 35819776 DOI: 10.1007/978-1-0716-2209-4_23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Numerous proteins directly or indirectly bind membranes to exert their roles in a wide variety of biological processes. Such membrane binding often occurs in the presence of an external mechanical force. It remains challenging to quantify these interactions using traditional experimental approaches based on a large number of molecules, due to ensemble averaging or the lack of mechanical force. Here we described a new single-molecule approach based on high-resolution optical tweezers to characterize protein-membrane interactions. A single membrane binding protein is attached to the lipid bilayer coated on a silica bead via a flexible polypeptide linker, tethered to another bead via a long DNA handle, and pulled away from the bilayer using optical tweezers. Dynamic protein binding and unbinding is detected by the corresponding changes in the extension of the protein-DNA tether with high spatiotemporal resolution, which reveals the membrane binding affinity, kinetics, and intermediates. We demonstrated the method using C2 domains of extended synaptotagmin 2 (E-Syt2) with a detailed protocol. The method can be widely applied to investigate complex protein-membrane interactions under well-controlled experimental conditions.
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Affiliation(s)
- Lu Ma
- Department of Cell Biology, Yale University School of Medicine, New Haven, CT, USA
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, China
| | - Jinghua Ge
- Department of Cell Biology, Yale University School of Medicine, New Haven, CT, USA
| | - Xin Bian
- Department of Cell Biology, Yale University School of Medicine, New Haven, CT, USA
- State Key Laboratory of Medicinal Chemical Biology, College of Life Sciences, Nankai University, Tianjin, China
| | - Yongli Zhang
- Department of Cell Biology, Yale University School of Medicine, New Haven, CT, USA.
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26
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Huang C, Heinlein M. Function of Plasmodesmata in the Interaction of Plants with Microbes and Viruses. Methods Mol Biol 2022; 2457:23-54. [PMID: 35349131 DOI: 10.1007/978-1-0716-2132-5_2] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Plasmodesmata (PD) are gated plant cell wall channels that allow the trafficking of molecules between cells and play important roles during plant development and in the orchestration of cellular and systemic signaling responses during interactions of plants with the biotic and abiotic environment. To allow gating, PD are equipped with signaling platforms and enzymes that regulate the size exclusion limit (SEL) of the pore. Plant-interacting microbes and viruses target PD with specific effectors to enhance their virulence and are useful probes to study PD functions.
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Affiliation(s)
- Caiping Huang
- Institut de Biologie Moléculaire des Plantes, CNRS, Université de Strasbourg, Strasbourg, France
| | - Manfred Heinlein
- Institut de Biologie Moléculaire des Plantes, CNRS, Université de Strasbourg, Strasbourg, France.
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27
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Ge J, Bian X, Ma L, Cai Y, Li Y, Yang J, Karatekin E, De Camilli P, Zhang Y. Stepwise membrane binding of extended synaptotagmins revealed by optical tweezers. Nat Chem Biol 2021; 18:313-320. [PMID: 34916620 DOI: 10.1038/s41589-021-00914-3] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2021] [Accepted: 09/29/2021] [Indexed: 12/15/2022]
Abstract
Extended synaptotagmins (E-Syts) mediate lipid exchange between the endoplasmic reticulum (ER) and the plasma membrane (PM). Anchored on the ER, E-Syts bind the PM via an array of C2 domains in a Ca2+- and lipid-dependent manner, drawing the two membranes close to facilitate lipid exchange. How these C2 domains bind the PM and regulate the ER-PM distance is not well understood. Here, we applied optical tweezers to dissect PM binding by E-Syt1 and E-Syt2. We detected Ca2+- and lipid-dependent membrane-binding kinetics of both E-Syts and determined the binding energies and rates of individual C2 domains or pairs. We incorporated these parameters in a theoretical model to recapitulate salient features of E-Syt-mediated membrane contacts observed in vivo, including their equilibrium distances and probabilities. Our methods can be applied to study other proteins containing multiple membrane-binding domains linked by disordered polypeptides.
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Affiliation(s)
- Jinghua Ge
- Department of Cell Biology, Yale University School of Medicine, New Haven, CT, USA
| | - Xin Bian
- Department of Cell Biology, Yale University School of Medicine, New Haven, CT, USA.,Department of Neuroscience, Yale University School of Medicine, New Haven, CT, USA.,Howard Hughes Medical Institute, Yale University School of Medicine, New Haven, CT, USA.,Program in Cellular Neuroscience, Neurodegeneration and Repair, Yale University School of Medicine, New Haven, CT, USA.,State Key Laboratory of Medicinal Chemical Biology, College of Life Sciences, Nankai University, Tianjin, China
| | - Lu Ma
- Department of Cell Biology, Yale University School of Medicine, New Haven, CT, USA.,Department of Cellular and Molecular Physiology, Yale University School of Medicine, New Haven, CT, USA.,Nanobiology Institute, Yale University, West Haven, CT, USA.,Beijing National Laboratory for Condensed Matter Physics and CAS Key Laboratory of Soft Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, China
| | - Yiying Cai
- Department of Cell Biology, Yale University School of Medicine, New Haven, CT, USA.,Department of Neuroscience, Yale University School of Medicine, New Haven, CT, USA.,Howard Hughes Medical Institute, Yale University School of Medicine, New Haven, CT, USA.,Program in Cellular Neuroscience, Neurodegeneration and Repair, Yale University School of Medicine, New Haven, CT, USA
| | - Yanghui Li
- Department of Cell Biology, Yale University School of Medicine, New Haven, CT, USA.,College of Optical and Electronic Technology, China Jiliang University, Hangzhou, China
| | - Jie Yang
- Department of Cell Biology, Yale University School of Medicine, New Haven, CT, USA
| | - Erdem Karatekin
- Department of Cellular and Molecular Physiology, Yale University School of Medicine, New Haven, CT, USA.,Nanobiology Institute, Yale University, West Haven, CT, USA.,Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT, USA.,Université de Paris, Saints-Pères Paris Institute for the Neurosciences (SPPIN), Centre National de la Recherche Scientifique (CNRS), Paris, France
| | - Pietro De Camilli
- Department of Cell Biology, Yale University School of Medicine, New Haven, CT, USA.,Department of Neuroscience, Yale University School of Medicine, New Haven, CT, USA.,Howard Hughes Medical Institute, Yale University School of Medicine, New Haven, CT, USA.,Program in Cellular Neuroscience, Neurodegeneration and Repair, Yale University School of Medicine, New Haven, CT, USA.,Kavli Institute for Neuroscience, Yale University School of Medicine, New Haven, CT, USA
| | - Yongli Zhang
- Department of Cell Biology, Yale University School of Medicine, New Haven, CT, USA. .,Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT, USA.
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28
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Lalioti V, Beznoussenko GV, Mironov AA, Sandoval IV. The E-Syt3 cleavage and traffic uncovers the primordial cisterna, a new organelle that mothers the lipid droplets in the adipocyte. Traffic 2021; 23:21-41. [PMID: 34693607 DOI: 10.1111/tra.12823] [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: 09/07/2021] [Accepted: 10/21/2021] [Indexed: 12/27/2022]
Abstract
Extended synaptotagmins are endoplasmic reticulum proteins consisting of an SMP domain and multiple C2 domains that bind phospholipids and Ca2+ . E-Syts create contact junctions between the ER and plasma membrane (PM) to facilitate the exchange of glycerophospholipids between the apposed membranes. We find in the differentiating adipocyte that the E-Syt3 carboxyl domain is cleaved by a multi-step mechanism that includes removing the C2C domain. Confocal and live-cell time-lapse studies show that truncated E-Syt3ΔC2C, as well as endogenous E-Syt3 and the coat protein PLIN1, target the LDs from an annular, single giant ER cisterna. Inhibition of the proteasome blocks the proteolytic cleavage of Esyt3 and E-Syt3ΔC2C and causes the E-Syt3ΔC2C retention in the giant cisterna. The Esyt3 and PLIN1 distributions and LDs biogenesis show that the primordial cisterna, as we call it, is the birth and nurturing site of LDs in the adipocyte. Isoproterenol-induced lipolysis results in loss of cytoplasmic LDs and reappearance of the primordial cisterna. Electron microscopy and 3D-electron tomography studies show that the primordial cisterna consists of a tightly packed network of varicose tubules with extensively blistered membranes. Rounds of homotypic fusions from nascent to mature LDs play a central role in LD growth. The knockdown of E-Syt3 inhibits LD biogenesis. The identification of the primordial cisterna, an organelle that substitutes the randomly scattered ER foci that mother the LDs in non-adipose cells, sets the stage for a better understanding of LD biogenesis in the adipocyte.
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Affiliation(s)
- Vasiliki Lalioti
- Centro de Biología Molecular Severo Ochoa, Department of Cell Biology and Immunology, Physiological and Pathological Processes, Madrid, Spain
| | - Galina V Beznoussenko
- Laboratory of Electron Microscopy, The FIRC Institute of Molecular Oncology, Milan, Italy
| | - Alexander A Mironov
- Laboratory of Electron Microscopy, The FIRC Institute of Molecular Oncology, Milan, Italy
| | - Ignacio V Sandoval
- Centro de Biología Molecular Severo Ochoa, Department of Cell Biology and Immunology, Physiological and Pathological Processes, Madrid, Spain
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29
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Benavente JL, Siliqi D, Infantes L, Lagartera L, Mills A, Gago F, Ruiz-López N, Botella MA, Sánchez-Barrena MJ, Albert A. The structure and flexibility analysis of the Arabidopsis synaptotagmin 1 reveal the basis of its regulation at membrane contact sites. Life Sci Alliance 2021; 4:e202101152. [PMID: 34408000 PMCID: PMC8380656 DOI: 10.26508/lsa.202101152] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2021] [Revised: 07/21/2021] [Accepted: 07/21/2021] [Indexed: 12/12/2022] Open
Abstract
Non-vesicular lipid transfer at ER and plasma membrane (PM) contact sites (CS) is crucial for the maintenance of membrane lipid homeostasis. Extended synaptotagmins (E-Syts) play a central role in this process as they act as molecular tethers of ER and PM and as lipid transfer proteins between these organelles. E-Syts are proteins constitutively anchored to the ER through an N-terminal hydrophobic segment and bind the PM via a variable number of C-terminal C2 domains. Synaptotagmins (SYTs) are the plant orthologous of E-Syts and regulate the ER-PM communication in response to abiotic stress. Combining different structural and biochemical techniques, we demonstrate that the binding of SYT1 to lipids occurs through a Ca2+-dependent lipid-binding site and by a site for phosphorylated forms of phosphatidylinositol, thus integrating two different molecular signals in response to stress. In addition, we show that SYT1 displays three highly flexible hinge points that provide conformational freedom to facilitate lipid extraction, protein loading, and subsequent transfer between PM and ER.
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Affiliation(s)
- Juan L Benavente
- Instituto de Química Física "Rocasolano," Consejo Superior de Investigaciones Científicas (CSIC), Madrid, Spain
| | - Dritan Siliqi
- Istituto di Cristallografia, Consiglio Nazionale delle Ricerche (CNR), Bari, Italy
| | - Lourdes Infantes
- Instituto de Química Física "Rocasolano," Consejo Superior de Investigaciones Científicas (CSIC), Madrid, Spain
| | | | - Alberto Mills
- Área de Farmacología, Departamento de Ciencias Biomédicas, Unidad Asociada al IQM-CSIC, Universidad de Alcalá, Madrid, Spain
| | - Federico Gago
- Área de Farmacología, Departamento de Ciencias Biomédicas, Unidad Asociada al IQM-CSIC, Universidad de Alcalá, Madrid, Spain
| | - Noemí Ruiz-López
- Departamento de Biología Molecular y Bioquímica. Instituto de Hortofruticultura Subtropical y Mediterránea "La Mayora," Universidad de Málaga-CSIC (IHSM-UMA-CSIC), Universidad de Málaga, Campus de Teatinos, Málaga, Spain
| | - Miguel A Botella
- Departamento de Biología Molecular y Bioquímica. Instituto de Hortofruticultura Subtropical y Mediterránea "La Mayora," Universidad de Málaga-CSIC (IHSM-UMA-CSIC), Universidad de Málaga, Campus de Teatinos, Málaga, Spain
| | - María J Sánchez-Barrena
- Instituto de Química Física "Rocasolano," Consejo Superior de Investigaciones Científicas (CSIC), Madrid, Spain
| | - Armando Albert
- Instituto de Química Física "Rocasolano," Consejo Superior de Investigaciones Científicas (CSIC), Madrid, Spain
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30
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Fang MY, Huang KH, Tu WJ, Chen YT, Pan PY, Hsiao WC, Ke YY, Tsou LK, Zhang MM. Chemoproteomic profiling reveals cellular targets of nitro-fatty acids. Redox Biol 2021; 46:102126. [PMID: 34509914 PMCID: PMC8441202 DOI: 10.1016/j.redox.2021.102126] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2021] [Revised: 09/02/2021] [Accepted: 09/03/2021] [Indexed: 02/02/2023] Open
Abstract
Nitro-fatty acids are a class of endogenous electrophilic lipid mediators with anti-inflammatory and cytoprotective effects in a wide range of inflammatory and fibrotic disease models. While these beneficial biological effects of nitro-fatty acids are mainly attributed to their ability to form covalent adducts with proteins, only a small number of proteins are known to be nitro-alkylated and the scope of protein nitro-alkylation remains undetermined. Here we describe the synthesis and application of a clickable nitro-fatty acid probe for the detection and first global identification of mammalian proteins that are susceptible to nitro-alkylation. 184 high confidence nitro-alkylated proteins were identified in THP1 macrophages, majority of which are novel targets of nitro-fatty acids, including extended synaptotagmin 2 (ESYT2), signal transducer and activator of transcription 3 (STAT3), toll-like receptor 2 (TLR2), retinoid X receptor alpha (RXRα) and glucocorticoid receptor (NR3C1). In particular, we showed that 9-nitro-oleate covalently modified and inhibited dexamethasone binding to NR3C1. Bioinformatic analyses revealed that nitro-alkylated proteins are highly enriched in endoplasmic reticulum and transmembrane proteins, and are overrepresented in lipid metabolism and transport pathways. This study significantly expands the scope of protein substrates targeted by nitro-fatty acids in living cells and provides a useful resource towards understanding the pleiotropic biological roles of nitro-fatty acids as signaling molecules or as multi-target therapeutic agents.
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Affiliation(s)
- Ming-Yu Fang
- Institute of Molecular and Genomic Medicine, National Health Research Institutes, Zhunan, Miaoli, 35053, Taiwan
| | - Kuan-Hsun Huang
- Institute of Biotechnology and Pharmaceutical Research, National Health Research Institutes, Zhunan, Miaoli, 35053, Taiwan
| | - Wei-Ju Tu
- Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, Taoyuan, Taiwan
| | - Yi-Ting Chen
- Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, Taoyuan, Taiwan; Department of Biomedical Sciences, College of Medicine, Chang Gung University, Taoyuan, Taiwan; Department of Nephrology, Chang Gung Memorial Hospital, Linkou Medical Center, Taoyuan, Taiwan
| | - Pei-Yun Pan
- Institute of Biotechnology and Pharmaceutical Research, National Health Research Institutes, Zhunan, Miaoli, 35053, Taiwan
| | - Wan-Chi Hsiao
- Institute of Molecular and Genomic Medicine, National Health Research Institutes, Zhunan, Miaoli, 35053, Taiwan; Institute of Biotechnology, National Tsing Hua University, Hsinchu, 30013, Taiwan
| | - Yi-Yu Ke
- Institute of Biotechnology and Pharmaceutical Research, National Health Research Institutes, Zhunan, Miaoli, 35053, Taiwan
| | - Lun K Tsou
- Institute of Biotechnology and Pharmaceutical Research, National Health Research Institutes, Zhunan, Miaoli, 35053, Taiwan
| | - Mingzi M Zhang
- Institute of Molecular and Genomic Medicine, National Health Research Institutes, Zhunan, Miaoli, 35053, Taiwan.
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31
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Intertwined and Finely Balanced: Endoplasmic Reticulum Morphology, Dynamics, Function, and Diseases. Cells 2021; 10:cells10092341. [PMID: 34571990 PMCID: PMC8472773 DOI: 10.3390/cells10092341] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2021] [Revised: 09/02/2021] [Accepted: 09/04/2021] [Indexed: 02/07/2023] Open
Abstract
The endoplasmic reticulum (ER) is an organelle that is responsible for many essential subcellular processes. Interconnected narrow tubules at the periphery and thicker sheet-like regions in the perinuclear region are linked to the nuclear envelope. It is becoming apparent that the complex morphology and dynamics of the ER are linked to its function. Mutations in the proteins involved in regulating ER structure and movement are implicated in many diseases including neurodegenerative diseases such as Alzheimer’s, Parkinson’s, and amyotrophic lateral sclerosis (ALS). The ER is also hijacked by pathogens to promote their replication. Bacteria such as Legionella pneumophila and Chlamydia trachomatis, as well as the Zika virus, bind to ER morphology and dynamics-regulating proteins to exploit the functions of the ER to their advantage. This review covers our understanding of ER morphology, including the functional subdomains and membrane contact sites that the organelle forms. We also focus on ER dynamics and the current efforts to quantify ER motion and discuss the diseases related to ER morphology and dynamics.
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32
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Raghu P, Basak B, Krishnan H. Emerging perspectives on multidomain phosphatidylinositol transfer proteins. Biochim Biophys Acta Mol Cell Biol Lipids 2021; 1866:158984. [PMID: 34098114 PMCID: PMC7611342 DOI: 10.1016/j.bbalip.2021.158984] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2021] [Revised: 05/23/2021] [Accepted: 05/25/2021] [Indexed: 12/09/2022]
Abstract
The phosphatidylinositol transfer protein domain (PITPd) is an evolutionarily conserved protein that is able to transfer phosphatidylinositol between membranes in vitro and in vivo. However some animal genomes also include genes that encode proteins where the PITPd is found in cis with a number of additional domains and recent large scale genome sequencing efforts indicate that this type of multidomain architecture is widespread in the animal kingdom. In Drosophila photoreceptors, the multidomain phosphatidylinositol transfer protein RDGB is required to regulate phosphoinositide turnover during G-protein activated phospholipase C signalling. Recent studies in flies and mammalian cell culture models have begun to elucidate functions for the non-PITPd of RDGB and its vertebrate orthologs. We review emerging evidence on the genomics, functional and cell biological perspectives of these multi-domain PITPd containing proteins.
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Affiliation(s)
- Padinjat Raghu
- National Centre for Biological Sciences, TIFR-GKVK Campus, Bellary Road, Bengaluru 560065, India.
| | - Bishal Basak
- National Centre for Biological Sciences, TIFR-GKVK Campus, Bellary Road, Bengaluru 560065, India
| | - Harini Krishnan
- National Centre for Biological Sciences, TIFR-GKVK Campus, Bellary Road, Bengaluru 560065, India
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33
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Ruiz-Lopez N, Pérez-Sancho J, del Valle AE, Haslam RP, Vanneste S, Catalá R, Perea-Resa C, Damme DV, García-Hernández S, Albert A, Vallarino J, Lin J, Friml J, Macho AP, Salinas J, Rosado A, Napier JA, Amorim-Silva V, Botella MA. Synaptotagmins at the endoplasmic reticulum-plasma membrane contact sites maintain diacylglycerol homeostasis during abiotic stress. THE PLANT CELL 2021; 33:2431-2453. [PMID: 33944955 PMCID: PMC8364230 DOI: 10.1093/plcell/koab122] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/08/2020] [Accepted: 04/25/2021] [Indexed: 05/07/2023]
Abstract
Endoplasmic reticulum-plasma membrane contact sites (ER-PM CS) play fundamental roles in all eukaryotic cells. Arabidopsis thaliana mutants lacking the ER-PM protein tether synaptotagmin1 (SYT1) exhibit decreased PM integrity under multiple abiotic stresses, such as freezing, high salt, osmotic stress, and mechanical damage. Here, we show that, together with SYT1, the stress-induced SYT3 is an ER-PM tether that also functions in maintaining PM integrity. The ER-PM CS localization of SYT1 and SYT3 is dependent on PM phosphatidylinositol-4-phosphate and is regulated by abiotic stress. Lipidomic analysis revealed that cold stress increased the accumulation of diacylglycerol at the PM in a syt1/3 double mutant relative to wild-type while the levels of most glycerolipid species remain unchanged. In addition, the SYT1-green fluorescent protein fusion preferentially binds diacylglycerol in vivo with little affinity for polar glycerolipids. Our work uncovers a SYT-dependent mechanism of stress adaptation counteracting the detrimental accumulation of diacylglycerol at the PM produced during episodes of abiotic stress.
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Affiliation(s)
- Noemi Ruiz-Lopez
- Departamento de Biología Molecular y Bioquímica, Instituto de Hortofruticultura Subtropical y Mediterránea “La Mayora”, Universidad de Málaga-Consejo Superior de Investigaciones Científicas (IHSM-UMA-CSIC), Universidad de Málaga, Málaga 12907, Spain
- Author for correspondence: (M.A.B.), (N.R.-L.)
| | - Jessica Pérez-Sancho
- Departamento de Biología Molecular y Bioquímica, Instituto de Hortofruticultura Subtropical y Mediterránea “La Mayora”, Universidad de Málaga-Consejo Superior de Investigaciones Científicas (IHSM-UMA-CSIC), Universidad de Málaga, Málaga 12907, Spain
- Shanghai Center for Plant Stress Biology, Chinese Academy of Sciences, Shanghai 201602, China
| | - Alicia Esteban del Valle
- Departamento de Biología Molecular y Bioquímica, Instituto de Hortofruticultura Subtropical y Mediterránea “La Mayora”, Universidad de Málaga-Consejo Superior de Investigaciones Científicas (IHSM-UMA-CSIC), Universidad de Málaga, Málaga 12907, Spain
| | | | - Steffen Vanneste
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent 9052, Belgium
- VIB Center for Plant Systems Biology, Ghent 9052, Belgium
| | - Rafael Catalá
- Departamento de Biotecnología Microbiana y de Plantas, Centro de Investigaciones Biológicas Margarita Salas-CSIC, Madrid, 28040, Spain
| | - Carlos Perea-Resa
- Departamento de Biotecnología Microbiana y de Plantas, Centro de Investigaciones Biológicas Margarita Salas-CSIC, Madrid, 28040, Spain
| | - Daniël Van Damme
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent 9052, Belgium
- VIB Center for Plant Systems Biology, Ghent 9052, Belgium
| | - Selene García-Hernández
- Departamento de Biología Molecular y Bioquímica, Instituto de Hortofruticultura Subtropical y Mediterránea “La Mayora”, Universidad de Málaga-Consejo Superior de Investigaciones Científicas (IHSM-UMA-CSIC), Universidad de Málaga, Málaga 12907, Spain
| | - Armando Albert
- Departamento de Cristalografía y Biología Estructural, Instituto de Química Física “Rocasolano”, Consejo Superior de Investigaciones Científicas, Madrid, 28006, Spain
| | - José Vallarino
- Departamento de Biología Molecular y Bioquímica, Instituto de Hortofruticultura Subtropical y Mediterránea “La Mayora”, Universidad de Málaga-Consejo Superior de Investigaciones Científicas (IHSM-UMA-CSIC), Universidad de Málaga, Málaga 12907, Spain
| | - Jinxing Lin
- College of Biological Sciences and Technology, Beijing Forestry University, Beijing, 100083, China
| | - Jiří Friml
- Institute of Science and Technology (IST), Klosterneuburg, 3400, Austria
| | - Alberto P. Macho
- Shanghai Center for Plant Stress Biology, Chinese Academy of Sciences, Shanghai 201602, China
| | - Julio Salinas
- Departamento de Biotecnología Microbiana y de Plantas, Centro de Investigaciones Biológicas Margarita Salas-CSIC, Madrid, 28040, Spain
| | - Abel Rosado
- Department of Botany, The University of British Columbia, Vancouver, Canada, BC V6T 1Z4
| | | | - Vitor Amorim-Silva
- Departamento de Biología Molecular y Bioquímica, Instituto de Hortofruticultura Subtropical y Mediterránea “La Mayora”, Universidad de Málaga-Consejo Superior de Investigaciones Científicas (IHSM-UMA-CSIC), Universidad de Málaga, Málaga 12907, Spain
| | - Miguel A. Botella
- Departamento de Biología Molecular y Bioquímica, Instituto de Hortofruticultura Subtropical y Mediterránea “La Mayora”, Universidad de Málaga-Consejo Superior de Investigaciones Científicas (IHSM-UMA-CSIC), Universidad de Málaga, Málaga 12907, Spain
- Author for correspondence: (M.A.B.), (N.R.-L.)
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Avula K, Singh B, Kumar PV, Syed GH. Role of Lipid Transfer Proteins (LTPs) in the Viral Life Cycle. Front Microbiol 2021; 12:673509. [PMID: 34248884 PMCID: PMC8260984 DOI: 10.3389/fmicb.2021.673509] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2021] [Accepted: 05/17/2021] [Indexed: 12/14/2022] Open
Abstract
Viruses are obligate parasites that depend on the host cell machinery for their replication and dissemination. Cellular lipids play a central role in multiple stages of the viral life cycle such as entry, replication, morphogenesis, and egress. Most viruses reorganize the host cell membranes for the establishment of viral replication complex. These specialized structures allow the segregation of replicating viral RNA from ribosomes and protect it from host nucleases. They also facilitate localized enrichment of cellular components required for viral replication and assembly. The specific composition of the lipid membrane governs its ability to form negative or positive curvature and possess a rigid or flexible form, which is crucial for membrane rearrangement and establishment of viral replication complexes. In this review, we highlight how different viruses manipulate host lipid transfer proteins and harness their functions to enrich different membrane compartments with specific lipids in order to facilitate multiple aspects of the viral life cycle.
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Affiliation(s)
- Kiran Avula
- Virus-Host Interaction Lab, Institute of Life Sciences, Bhubaneshwar, India.,Regional Centre for Biotechnology, Faridabad, India
| | - Bharati Singh
- Virus-Host Interaction Lab, Institute of Life Sciences, Bhubaneshwar, India.,School of Biotechnology, Kalinga Institute of Industrial Technology, Bhubaneshwar, India
| | - Preethy V Kumar
- Virus-Host Interaction Lab, Institute of Life Sciences, Bhubaneshwar, India.,School of Biotechnology, Kalinga Institute of Industrial Technology, Bhubaneshwar, India
| | - Gulam H Syed
- Virus-Host Interaction Lab, Institute of Life Sciences, Bhubaneshwar, India
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35
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Qian T, Li C, He R, Wan C, Liu Y, Yu H. Calcium-dependent and -independent lipid transfer mediated by tricalbins in yeast. J Biol Chem 2021; 296:100729. [PMID: 33933446 PMCID: PMC8163979 DOI: 10.1016/j.jbc.2021.100729] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2021] [Revised: 04/23/2021] [Accepted: 04/28/2021] [Indexed: 11/12/2022] Open
Abstract
Membrane contact sites (MCSs) formed between the endoplasmic reticulum (ER) and the plasma membrane (PM) provide a platform for nonvesicular lipid exchange. The ER-anchored tricalbins (Tcb1, Tcb2, and Tcb3) are critical tethering factors at ER–PM MCSs in yeast. Tricalbins possess a synaptotagmin-like mitochondrial-lipid-binding protein (SMP) domain and multiple Ca2+-binding C2 domains. Although tricalbins have been suggested to be involved in lipid exchange at the ER–PM MCSs, it remains unclear whether they directly mediate lipid transport. Here, using in vitro lipid transfer assays, we discovered that tricalbins are capable of transferring phospholipids between membranes. Unexpectedly, while its lipid transfer activity was markedly elevated by Ca2+, Tcb3 constitutively transferred lipids even in the absence of Ca2+. The stimulatory activity of Ca2+ on Tcb3 required intact Ca2+-binding sites on both the C2C and C2D domains of Tcb3, while Ca2+-independent lipid transport was mediated by the SMP domain that transferred lipids via direct interactions with phosphatidylserine and other negatively charged lipid molecules. These findings establish tricalbins as lipid transfer proteins, and reveal Ca2+-dependent and -independent lipid transfer activities mediated by these tricalbins, providing new insights into their mechanism in maintaining PM integrity at ER–PM MCSs.
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Affiliation(s)
- Tiantian Qian
- Jiangsu Key Laboratory for Molecular and Medical Biotechnology, College of Life Sciences, Nanjing Normal University, Nanjing, China
| | - Chenlu Li
- Jiangsu Key Laboratory for Molecular and Medical Biotechnology, College of Life Sciences, Nanjing Normal University, Nanjing, China
| | - Ruyue He
- Jiangsu Key Laboratory for Molecular and Medical Biotechnology, College of Life Sciences, Nanjing Normal University, Nanjing, China
| | - Chun Wan
- Department of Molecular, Cellular and Developmental Biology, University of Colorado, Boulder, Colorado, USA
| | - Yinghui Liu
- Jiangsu Key Laboratory for Molecular and Medical Biotechnology, College of Life Sciences, Nanjing Normal University, Nanjing, China.
| | - Haijia Yu
- Jiangsu Key Laboratory for Molecular and Medical Biotechnology, College of Life Sciences, Nanjing Normal University, Nanjing, China.
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36
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Yeo HK, Park TH, Kim HY, Jang H, Lee J, Hwang GS, Ryu SE, Park SH, Song HK, Ban HS, Yoon HJ, Lee BI. Phospholipid transfer function of PTPIP51 at mitochondria-associated ER membranes. EMBO Rep 2021; 22:e51323. [PMID: 33938112 DOI: 10.15252/embr.202051323] [Citation(s) in RCA: 54] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2020] [Revised: 02/24/2021] [Accepted: 03/22/2021] [Indexed: 01/08/2023] Open
Abstract
In eukaryotic cells, mitochondria are closely tethered to the endoplasmic reticulum (ER) at sites called mitochondria-associated ER membranes (MAMs). Ca2+ ion and phospholipid transfer occurs at MAMs to support diverse cellular functions. Unlike those in yeast, the protein complexes involved in phospholipid transfer at MAMs in humans have not been identified. Here, we determine the crystal structure of the tetratricopeptide repeat domain of PTPIP51 (PTPIP51_TPR), a mitochondrial protein that interacts with the ER-anchored VAPB protein at MAMs. The structure of PTPIP51_TPR shows an archetypal TPR fold, and an electron density map corresponding to an unidentified lipid-like molecule probably derived from the protein expression host is found in the structure. We reveal functions of PTPIP51 in phospholipid binding/transfer, particularly of phosphatidic acid, in vitro. Depletion of PTPIP51 in cells reduces the mitochondrial cardiolipin level. Additionally, we confirm that the PTPIP51-VAPB interaction is mediated by the FFAT-like motif of PTPIP51 and the MSP domain of VAPB. Our findings suggest that PTPIP51 is a phospholipid transfer protein with a MAM-tethering function.
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Affiliation(s)
- Hyun Ku Yeo
- Research Institute, National Cancer Center, Goyang-si, Korea
| | - Tae Hyun Park
- Research Institute, National Cancer Center, Goyang-si, Korea.,Department of Bioengineering, Hanyang University, Seoul, Korea
| | - Hee Yeon Kim
- Research Institute, National Cancer Center, Goyang-si, Korea
| | - Hyonchol Jang
- Research Institute, National Cancer Center, Goyang-si, Korea.,Department of Cancer Biomedical Science, National Cancer Center Graduate School of Cancer Science and Policy, Goyang-si, Korea
| | - Jueun Lee
- Integrated Metabolomics Research Group, Western Seoul Center, Korea Basic Science Institute, Seoul, Korea
| | - Geum-Sook Hwang
- Integrated Metabolomics Research Group, Western Seoul Center, Korea Basic Science Institute, Seoul, Korea.,Department of Chemistry and Nano Science, Ewha Womans University, Seoul, Korea
| | - Seong Eon Ryu
- Department of Bioengineering, Hanyang University, Seoul, Korea
| | - Si Hoon Park
- Department of Life Sciences, Korea University, Seoul, Korea
| | - Hyun Kyu Song
- Department of Life Sciences, Korea University, Seoul, Korea
| | - Hyun Seung Ban
- Korea Research Institute of Bioscience and Biotechnology, Daejeon, Korea
| | - Hye-Jin Yoon
- Department of Chemistry, College of Natural Sciences, Seoul National University, Seoul, Korea
| | - Byung Il Lee
- Research Institute, National Cancer Center, Goyang-si, Korea.,Department of Cancer Biomedical Science, National Cancer Center Graduate School of Cancer Science and Policy, Goyang-si, Korea
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37
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Crul T, Maléth J. Endoplasmic Reticulum-Plasma Membrane Contact Sites as an Organizing Principle for Compartmentalized Calcium and cAMP Signaling. Int J Mol Sci 2021; 22:ijms22094703. [PMID: 33946838 PMCID: PMC8124356 DOI: 10.3390/ijms22094703] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2021] [Revised: 04/20/2021] [Accepted: 04/27/2021] [Indexed: 01/14/2023] Open
Abstract
In eukaryotic cells, ultimate specificity in activation and action-for example, by means of second messengers-of the myriad of signaling cascades is primordial. In fact, versatile and ubiquitous second messengers, such as calcium (Ca2+) and cyclic adenosine monophosphate (cAMP), regulate multiple-sometimes opposite-cellular functions in a specific spatiotemporal manner. Cells achieve this through segregation of the initiators and modulators to specific plasma membrane (PM) subdomains, such as lipid rafts and caveolae, as well as by dynamic close contacts between the endoplasmic reticulum (ER) membrane and other intracellular organelles, including the PM. Especially, these membrane contact sites (MCSs) are currently receiving a lot of attention as their large influence on cell signaling regulation and cell physiology is increasingly appreciated. Depletion of ER Ca2+ stores activates ER membrane STIM proteins, which activate PM-residing Orai and TRPC Ca2+ channels at ER-PM contact sites. Within the MCS, Ca2+ fluxes relay to cAMP signaling through highly interconnected networks. However, the precise mechanisms of MCS formation and the influence of their dynamic lipid environment on their functional maintenance are not completely understood. The current review aims to provide an overview of our current understanding and to identify open questions of the field.
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Affiliation(s)
- Tim Crul
- First Department of Medicine, University of Szeged, H6720 Szeged, Hungary
- HAS-USZ Momentum Epithelial Cell Signaling and Secretion Research Group, University of Szeged, H6720 Szeged, Hungary
- HCEMM-SZTE Molecular Gastroenterology Research Group, University of Szeged, H6720 Szeged, Hungary
- Correspondence: (T.C.); (J.M.)
| | - József Maléth
- First Department of Medicine, University of Szeged, H6720 Szeged, Hungary
- HAS-USZ Momentum Epithelial Cell Signaling and Secretion Research Group, University of Szeged, H6720 Szeged, Hungary
- HCEMM-SZTE Molecular Gastroenterology Research Group, University of Szeged, H6720 Szeged, Hungary
- Correspondence: (T.C.); (J.M.)
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38
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Gao Y, Xiong J, Chu QZ, Ji WK. PDZD8-mediated lipid transfer at contacts between the ER and late endosomes/lysosomes is required for neurite outgrowth. J Cell Sci 2021; 135:256568. [PMID: 33912962 DOI: 10.1242/jcs.255026] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Accepted: 02/17/2021] [Indexed: 12/22/2022] Open
Abstract
Membrane contact sites (MCSs) between the endoplasmic reticulum (ER) and late endosomes/lysosomes (LE/lys) are emerging as critical hubs for diverse cellular events, and changes in their extents are linked to severe neurological diseases. While recent studies show that the synaptotagmin-like mitochondrial-lipid-binding (SMP) domain-containing protein PDZD8 may mediate the formation of ER-LE/lys MCSs, the cellular functions of PDZD8 remain largely elusive. Here, we attempt to investigate the lipid transfer activities of PDZD8 and the extent to which its cellular functions depend on its lipid transfer activities. In accordance with recent studies, we demonstrate that PDZD8 is a protrudin (ZFYVE27)-interacting protein and that PDZD8 acts as a tether at ER-LE/lys MCSs. Furthermore, we discover that the SMP domain of PDZD8 binds glycerophospholipids and ceramides both in vivo and in vitro, and that the SMP domain can transport lipids between membranes in vitro. Functionally, PDZD8 is required for LE/lys positioning and neurite outgrowth, which is dependent on the lipid transfer activity of the SMP domain.
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Affiliation(s)
- Yuan Gao
- Department of Biochemistry and Molecular Biology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, 430030, China
| | - Juan Xiong
- Department of Anesthesiology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, 430030, China
| | - Qing-Zhu Chu
- Department of Biochemistry and Molecular Biology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, 430030, China
| | - Wei-Ke Ji
- Department of Biochemistry and Molecular Biology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, 430030, China
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39
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Rosado A, Bayer EM. Geometry and cellular function of organelle membrane interfaces. PLANT PHYSIOLOGY 2021; 185:650-662. [PMID: 33793898 PMCID: PMC8133572 DOI: 10.1093/plphys/kiaa079] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/03/2020] [Accepted: 10/17/2020] [Indexed: 05/09/2023]
Abstract
A vast majority of cellular processes take root at the surface of biological membranes. By providing a two-dimensional platform with limited diffusion, membranes are, by nature, perfect devices to concentrate signaling and metabolic components. As such, membranes often act as "key processors" of cellular information. Biological membranes are highly dynamic and deformable and can be shaped into curved, tubular, or flat conformations, resulting in differentiated biophysical properties. At membrane contact sites, membranes from adjacent organelles come together into a unique 3D configuration, forming functionally distinct microdomains, which facilitate spatially regulated functions, such as organelle communication. Here, we describe the diversity of geometries of contact site-forming membranes in different eukaryotic organisms and explore the emerging notion that their shape, 3D architecture, and remodeling jointly define their cellular activity. The review also provides selected examples highlighting changes in membrane contact site architecture acting as rapid and local responses to cellular perturbations, and summarizes our current understanding of how those structural changes confer functional specificity to those cellular territories.
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Affiliation(s)
- Abel Rosado
- Department of Botany, University of British Columbia, Vancouver, BC, Canada
| | - Emmanuelle M Bayer
- Univ. Bordeaux, CNRS, Laboratoire de Biogenèse Membranaire, UMR 5200, F-33140 Villenave d’Ornon, France
- Author for communication:
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40
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Hewlett B, Singh NP, Vannier C, Galli T. ER-PM Contact Sites - SNARING Actors in Emerging Functions. Front Cell Dev Biol 2021; 9:635518. [PMID: 33681218 PMCID: PMC7928305 DOI: 10.3389/fcell.2021.635518] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Accepted: 01/21/2021] [Indexed: 11/13/2022] Open
Abstract
The compartmentalisation achieved by confining cytoplasm into membrane-enclosed organelles in eukaryotic cells is essential for maintaining vital functions including ATP production, synthetic and degradative pathways. While intracellular organelles are highly specialised in these functions, the restricting membranes also impede exchange of molecules responsible for the synchronised and responsive cellular activities. The initial identification of contact sites between the ER and plasma membrane (PM) provided a potential candidate structure for communication between organelles without mixing by fusion. Over the past decades, research has revealed a far broader picture of the events. Membrane contact sites (MCSs) have been recognized as increasingly important actors in cell differentiation, plasticity and maintenance, and, upon dysfunction, responsible for pathological conditions such as cancer and neurodegenerative diseases. Present in multiple organelles and cell types, MCSs promote transport of lipids and Ca2+ homoeostasis, with a range of associated protein families. Interestingly, each MCS displays a unique molecular signature, adapted to organelle functions. This review will explore the literature describing the molecular components and interactions taking place at ER-PM contact sites, their functions, and implications in eukaryotic cells, particularly neurons, with emphasis on lipid transfer proteins and emerging function of SNAREs.
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Affiliation(s)
- Bailey Hewlett
- INSERM U1266, Institut de Psychiatrie et Neurosciences de Paris, Université de Paris, Paris, France
| | - Neha Pratap Singh
- INSERM U1266, Institut de Psychiatrie et Neurosciences de Paris, Université de Paris, Paris, France
| | - Christian Vannier
- INSERM U1266, Institut de Psychiatrie et Neurosciences de Paris, Université de Paris, Paris, France
| | - Thierry Galli
- INSERM U1266, Institut de Psychiatrie et Neurosciences de Paris, Université de Paris, Paris, France.,GHU PARIS Psychiatrie and Neurosciences, Paris, France
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41
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Li C, Qian T, He R, Wan C, Liu Y, Yu H. Endoplasmic Reticulum-Plasma Membrane Contact Sites: Regulators, Mechanisms, and Physiological Functions. Front Cell Dev Biol 2021; 9:627700. [PMID: 33614657 PMCID: PMC7889955 DOI: 10.3389/fcell.2021.627700] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2020] [Accepted: 01/13/2021] [Indexed: 12/13/2022] Open
Abstract
The endoplasmic reticulum (ER) forms direct membrane contact sites with the plasma membrane (PM) in eukaryotic cells. These ER-PM contact sites play essential roles in lipid homeostasis, ion dynamics, and cell signaling, which are carried out by protein-protein or protein-lipid interactions. Distinct tethering factors dynamically control the architecture of ER-PM junctions in response to intracellular signals or external stimuli. The physiological roles of ER-PM contact sites are dependent on a variety of regulators that individually or cooperatively perform functions in diverse cellular processes. This review focuses on proteins functioning at ER-PM contact sites and highlights the recent progress in their mechanisms and physiological roles.
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Affiliation(s)
- Chenlu Li
- Jiangsu Key Laboratory for Molecular and Medical Biotechnology, College of Life Sciences, Nanjing Normal University, Nanjing, China
| | - Tiantian Qian
- Jiangsu Key Laboratory for Molecular and Medical Biotechnology, College of Life Sciences, Nanjing Normal University, Nanjing, China
| | - Ruyue He
- Jiangsu Key Laboratory for Molecular and Medical Biotechnology, College of Life Sciences, Nanjing Normal University, Nanjing, China
| | - Chun Wan
- Department of Molecular, Cellular and Developmental Biology, University of Colorado, Boulder, CO, United States
| | - Yinghui Liu
- Jiangsu Key Laboratory for Molecular and Medical Biotechnology, College of Life Sciences, Nanjing Normal University, Nanjing, China
| | - Haijia Yu
- Jiangsu Key Laboratory for Molecular and Medical Biotechnology, College of Life Sciences, Nanjing Normal University, Nanjing, China
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42
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Cremer T, Neefjes J, Berlin I. The journey of Ca 2+ through the cell - pulsing through the network of ER membrane contact sites. J Cell Sci 2020; 133:133/24/jcs249136. [PMID: 33376155 DOI: 10.1242/jcs.249136] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Calcium is the third most abundant metal on earth, and the fundaments of its homeostasis date back to pre-eukaryotic life forms. In higher organisms, Ca2+ serves as a cofactor for a wide array of (enzymatic) interactions in diverse cellular contexts and constitutes the most important signaling entity in excitable cells. To enable responsive behavior, cytosolic Ca2+ concentrations are kept low through sequestration into organellar stores, particularly the endoplasmic reticulum (ER), but also mitochondria and lysosomes. Specific triggers are then used to instigate a local release of Ca2+ on demand. Here, communication between organelles comes into play, which is accomplished through intimate yet dynamic contacts, termed membrane contact sites (MCSs). The field of MCS biology in relation to cellular Ca2+ homeostasis has exploded in recent years. Taking advantage of this new wealth of knowledge, in this Review, we invite the reader on a journey of Ca2+ flux through the ER and its associated MCSs. New mechanistic insights and technological advances inform the narrative on Ca2+ acquisition and mobilization at these sites of communication between organelles, and guide the discussion of their consequences for cellular physiology.
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Affiliation(s)
- Tom Cremer
- Department of Cell and Chemical Biology, Leiden University Medical Center LUMC, Einthovenweg 20, 2300RC Leiden, The Netherlands
| | - Jacques Neefjes
- Department of Cell and Chemical Biology, Leiden University Medical Center LUMC, Einthovenweg 20, 2300RC Leiden, The Netherlands
| | - Ilana Berlin
- Department of Cell and Chemical Biology, Leiden University Medical Center LUMC, Einthovenweg 20, 2300RC Leiden, The Netherlands
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43
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Kimura AK, Kimura T. Phosphatidylserine biosynthesis pathways in lipid homeostasis: Toward resolution of the pending central issue for decades. FASEB J 2020; 35:e21177. [PMID: 33205488 DOI: 10.1096/fj.202001802r] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2020] [Revised: 10/17/2020] [Accepted: 10/26/2020] [Indexed: 12/28/2022]
Abstract
Enzymatic control of lipid homeostasis in the cell is a vital element in the complex organization of life. Phosphatidylserine (PS) is an essential anionic phospholipid of cell membranes, and conducts numerous roles for their structural and functional integrity. In mammalian cells, two distinct enzymes phosphatidylserine synthases-1 (PSS1) and -2 (PSS2) in the mitochondria-associated membrane (MAM) in the ER perform de novo synthesis of PS. It is based on base-exchange reactions of the preexisting dominant phospholipids phosphatidylcholine (PC) and phosphatidylethanolamine (PE). While PSS2 specifically catalyzes the reaction "PE → PS," whether or not PSS1 is responsible for the same reaction along with the reaction "PC → PS" remains unsettled despite its fundamental impact on the major stoichiometry. We propose here that a key but the only report that appeared to have put scientists on hold for decades in answering to this issue may be viewed consistently with other available research reports; PSS1 utilizes the two dominant phospholipid classes at a similar intrinsic rate. In this review, we discuss the issue in view of the current information for the enzyme machineries, membrane structure and dynamics, intracellular network of lipid transport, and PS synthesis in health and disease. Resolution of the pending issue is thus critical in advancing our understanding of roles of the essential anionic lipid in biology, health, and disease.
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Affiliation(s)
- Atsuko K Kimura
- Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, ON, Canada
| | - Tomohiro Kimura
- Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, ON, Canada
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44
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Ikeda A, Schlarmann P, Kurokawa K, Nakano A, Riezman H, Funato K. Tricalbins Are Required for Non-vesicular Ceramide Transport at ER-Golgi Contacts and Modulate Lipid Droplet Biogenesis. iScience 2020; 23:101603. [PMID: 33205016 PMCID: PMC7648140 DOI: 10.1016/j.isci.2020.101603] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2020] [Revised: 07/20/2020] [Accepted: 09/21/2020] [Indexed: 12/14/2022] Open
Abstract
Lipid composition varies among organelles, and the distinct lipid composition is important for specific functions of each membrane. Lipid transport between organelles, which is critical for the maintenance of membrane lipid composition, occurs by either vesicular or non-vesicular mechanisms. In yeast, ceramide synthesized in the endoplasmic reticulum (ER) is transported to the Golgi apparatus where inositolphosphorylceramide (IPC) is formed. Here we show that a fraction of Tcb3p, a yeast tricalbin protein, localizes to ER-Golgi contact sites. Tcb3p and their homologs Tcb1p and Tcb2p are required for formation of ER-Golgi contacts and non-vesicular ceramide transport. Absence of Tcb1p, Tcb2p, and Tcb3p increases acylceramide synthesis and subsequent lipid droplet (LD) formation. As LD can sequester excess lipids, we propose that tricalbins act as regulators of ceramide transport at ER-Golgi contact sites to help reduce a potentially toxic accumulation of ceramides. Yeast tricalbin Tcb3p localizes at ER-Golgi contact sites Lack of tricalbins reduces ER-Golgi contacts Tricalbins regulate non-vesicular ceramide transport Tricalbin deletion causes both acylceramide and lipid droplet accumulation
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Affiliation(s)
- Atsuko Ikeda
- Graduate School of Biosphere Science, Hiroshima University, Kagamiyama 1-4-4, Higashi-Hiroshima 739-8528, Japan
| | - Philipp Schlarmann
- Graduate School of Biosphere Science, Hiroshima University, Kagamiyama 1-4-4, Higashi-Hiroshima 739-8528, Japan
| | - Kazuo Kurokawa
- Live Cell Super-Resolution Imaging Research Team, RIKEN Center for Advanced Photonics, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - Akihiko Nakano
- Live Cell Super-Resolution Imaging Research Team, RIKEN Center for Advanced Photonics, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - Howard Riezman
- Swiss National Centre for Competence in Research in Chemical Biology and Department of Biochemistry, University of Geneva, 1211 Geneva, Switzerland
| | - Kouichi Funato
- Graduate School of Biosphere Science, Hiroshima University, Kagamiyama 1-4-4, Higashi-Hiroshima 739-8528, Japan
- Graduate School of Integrated Sciences for Life, Hiroshima University, Kagamiyama 1-4-4, Higashi-Hiroshima 739-8528, Japan
- Corresponding author
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45
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Sun Y, Zhou S, Shi Y, Zhou Y, Zhang Y, Liu K, Zhu Y, Han X. Inhibition of miR-153, an IL-1β-responsive miRNA, prevents beta cell failure and inflammation-associated diabetes. Metabolism 2020; 111:154335. [PMID: 32795559 DOI: 10.1016/j.metabol.2020.154335] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/07/2020] [Revised: 07/14/2020] [Accepted: 07/30/2020] [Indexed: 12/30/2022]
Abstract
OBJECTIVE Systemic levels of up-regulated IL-1β and IL-1 receptors promote the pathogenesis of inflammation-associated diabetes. IL-1 receptor antagonist (IL-Ra) has shown slightly elevated beta cell function in patients with type 2 diabetes without significant improvement of hyperglycaemia. We investigated whether miR-153, an IL-1β responsive miRNA, could mimic IL-1β effects and whether its interruption would improve blood glucose control then offer an assistant curative approach to inflammation-associated diabetes. MATERIALS/METHODS Antago-miR-153 and Ago-miR-153 were injected into the abdominal aorta of leptin receptor-mutant db/db mice and C57BL/6 J mice, respectively. Blood glucose levels, glucose tolerance tests, insulin tolerance tests and insulin levels were regularly checked. Proteomic profiling combined with unbiased bioinformatics analysis, as well as experimental techniques, were utilized to identify target genes of miR-153. Anti-miR-153 and plasmid-based recovery assays were also performed using primary mouse islets and beta cell lines. RESULTS The miR-153 expression level was increased in IL-1β-treated beta cells and primary islets from the diabetic rodents. Pancreas overexpression of miR-153 caused glucose intolerance in C57BL/6 J mice but no alterations in body weight or insulin sensitivity. The inhibition of miR-153 temporarily reduced hyperglycaemia of db/db mice due to enhanced insulin secretion. Antago-miR-153 treatment ameliorated glucose intolerance in db/db mice during our observation period but did not improve insulin sensitivity. Mechanistically, miR-153 targeted three members of SNAREs to disturb insulin granule docking, thereby decreasing basal insulin secretion. Overexpression of anti-miR-153 or SNARE rescued the IL-1β-induced basal insulin secretion defect. Furthermore, miR-153 targeted beta cell-specific transcriptional factors and survival molecules to inhibit insulin biosynthesis and cell viability. CONCLUSIONS The IL-1β-responsive miR-153 targets SNAREs, beta cell specific TFs and other key factors to eventually causes beta cell failure. Inhibiting miR-153 with Antago-miR-153 prevents hyperglycaemia in db/db mice, indicating that miR-153 may be a promising therapeutic target for the treatment of inflammation-associated diabetes.
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Affiliation(s)
- Yi Sun
- Key Laboratory of Human Functional Genomics of Jiangsu Province, Department of Biochemistry and Molecular Biology, Nanjing Medical University, Nanjing, Jiangsu, China
| | - Shixiang Zhou
- Key Laboratory of Human Functional Genomics of Jiangsu Province, Department of Biochemistry and Molecular Biology, Nanjing Medical University, Nanjing, Jiangsu, China; Department of Orthopedic Surgery, the Second Hospital of Nanjing, Nanjing University of Chinese Medicine, Nanjing, Jiangsu, China
| | - Ying Shi
- Key Laboratory of Human Functional Genomics of Jiangsu Province, Department of Biochemistry and Molecular Biology, Nanjing Medical University, Nanjing, Jiangsu, China
| | - Yuncai Zhou
- Key Laboratory of Human Functional Genomics of Jiangsu Province, Department of Biochemistry and Molecular Biology, Nanjing Medical University, Nanjing, Jiangsu, China
| | - Yan Zhang
- Key Laboratory of Human Functional Genomics of Jiangsu Province, Department of Biochemistry and Molecular Biology, Nanjing Medical University, Nanjing, Jiangsu, China
| | - Kerong Liu
- Key Laboratory of Human Functional Genomics of Jiangsu Province, Department of Biochemistry and Molecular Biology, Nanjing Medical University, Nanjing, Jiangsu, China
| | - Yunxia Zhu
- Key Laboratory of Human Functional Genomics of Jiangsu Province, Department of Biochemistry and Molecular Biology, Nanjing Medical University, Nanjing, Jiangsu, China.
| | - Xiao Han
- Key Laboratory of Human Functional Genomics of Jiangsu Province, Department of Biochemistry and Molecular Biology, Nanjing Medical University, Nanjing, Jiangsu, China.
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Gallo A, Danglot L, Giordano F, Hewlett B, Binz T, Vannier C, Galli T. Role of the Sec22b-E-Syt complex in neurite growth and ramification. J Cell Sci 2020; 133:jcs.247148. [PMID: 32843578 DOI: 10.1242/jcs.247148] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2020] [Accepted: 08/12/2020] [Indexed: 12/12/2022] Open
Abstract
Axons and dendrites are long and often ramified neurites that need particularly intense plasma membrane (PM) expansion during the development of the nervous system. Neurite growth depends on non-fusogenic Sec22b-Stx1 SNARE complexes at endoplasmic reticulum (ER)-PM contacts. Here, we show that Sec22b interacts with members of the extended synaptotagmin (E-Syt) family of ER lipid transfer proteins (LTPs), and this interaction depends on the longin domain of Sec22b. Overexpression of E-Syts stabilizes Sec22b-Stx1 association, whereas silencing of E-Syts has the opposite effect. Overexpression of wild-type E-Syt2, but not mutants unable to transfer lipids or attach to the ER, increase the formation of axonal filopodia and ramification of neurites in developing neurons. This effect is inhibited by a clostridial neurotoxin cleaving Stx1, and expression of the Sec22b longin domain and a Sec22b mutant with an extended linker between the SNARE and transmembrane domains. We conclude that Sec22b-Stx1 ER-PM contact sites contribute to PM expansion by interacting with LTPs, such as E-Syts.This article has an associated First Person interview with the first author of the paper.
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Affiliation(s)
- Alessandra Gallo
- Université de Paris, Institute of Psychiatry and Neuroscience of Paris (IPNP), INSERM, Membrane Traffic in Healthy & Diseased Brain, F-75014 Paris, France.,Ecole des Neurosciences de Paris (ENP), F-75006 Paris, France
| | - Lydia Danglot
- Université de Paris, Institute of Psychiatry and Neuroscience of Paris (IPNP), INSERM, Membrane Traffic in Healthy & Diseased Brain, F-75014 Paris, France
| | - Francesca Giordano
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Paris-Sud University, Paris-Saclay University, Gif-sur-Yvette cedex, 91198, France
| | - Bailey Hewlett
- Université de Paris, Institute of Psychiatry and Neuroscience of Paris (IPNP), INSERM, Membrane Traffic in Healthy & Diseased Brain, F-75014 Paris, France
| | - Thomas Binz
- Medizinische Hochschule Hannover, Institut für Physiologische Chemie OE4310, 30625 Hannover, Germany
| | - Christian Vannier
- Université de Paris, Institute of Psychiatry and Neuroscience of Paris (IPNP), INSERM, Membrane Traffic in Healthy & Diseased Brain, F-75014 Paris, France
| | - Thierry Galli
- Université de Paris, Institute of Psychiatry and Neuroscience of Paris (IPNP), INSERM, Membrane Traffic in Healthy & Diseased Brain, F-75014 Paris, France .,GHU PARIS psychiatrie & neurosciences, F-75014 Paris, France
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47
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The short isoform of extended synaptotagmin-2 controls Ca 2+ dynamics in T cells via interaction with STIM1. Sci Rep 2020; 10:14433. [PMID: 32879390 PMCID: PMC7468131 DOI: 10.1038/s41598-020-71489-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2020] [Accepted: 08/14/2020] [Indexed: 11/16/2022] Open
Abstract
Ca2+ release-activated Ca2+ (CRAC) channels elevate cytoplasmic Ca2+ concentration, which is essential for T cell activation, differentiation and effector functions. T cell receptor stimulation induces depletion of the endoplasmic reticulum (ER) Ca2+ stores, which is sensed by stromal interaction molecule 1 (STIM1). STIM1 translocates to the ER-plasma membrane (PM) junctions to interact with ORAI1, the pore subunit of the CRAC channels. Here, we show that two members of the extended synaptotagmin (E-Syt) family, E-Syt1, and the short isoform of E-Syt2 (E-Syt2S), contribute to activation of CRAC channels in T cells. Knockdown or deletion of both ESYT1 and ESYT2 reduced store-operated Ca2+ entry (SOCE) and ORAI1-STIM1 clustering in Jurkat T cells. Further, depletion of E-Syts in primary T cells decreased Ca2+ entry and cytokine production. While the ER-PM junctions were reduced in both HeLa and Jurkat T cells deleted for ESYT1 and ESYT2, SOCE was impaired only in Jurkat T cells, suggesting that the membrane-tethering function of E-Syts is distinct from their role in SOCE. Mechanistically, E-Syt2S, the predominant isoform of E-Syt2 in T cells, recruited STIM1 to the junctions via a direct interaction. This study demonstrates a membrane-tethering-independent role of E-Syts in activation of CRAC channels in T cells.
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Urbina FL, Gupton SL. SNARE-Mediated Exocytosis in Neuronal Development. Front Mol Neurosci 2020; 13:133. [PMID: 32848598 PMCID: PMC7427632 DOI: 10.3389/fnmol.2020.00133] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2020] [Accepted: 07/02/2020] [Indexed: 12/15/2022] Open
Abstract
The formation of the nervous system involves establishing complex networks of synaptic connections between proper partners. This developmental undertaking requires the rapid expansion of the plasma membrane surface area as neurons grow and polarize, extending axons through the extracellular environment. Critical to the expansion of the plasma membrane and addition of plasma membrane material is exocytic vesicle fusion, a regulated mechanism driven by soluble N-ethylmaleimide-sensitive factor attachment proteins receptors (SNAREs). Since their discovery, SNAREs have been implicated in several critical neuronal functions involving exocytic fusion in addition to synaptic transmission, including neurite initiation and outgrowth, axon specification, axon extension, and synaptogenesis. Decades of research have uncovered a rich variety of SNARE expression and function. The basis of SNARE-mediated fusion, the opening of a fusion pore, remains an enigmatic event, despite an incredible amount of research, as fusion is not only heterogeneous but also spatially small and temporally fast. Multiple modes of exocytosis have been proposed, with full-vesicle fusion (FFV) and kiss-and-run (KNR) being the best described. Whereas most in vitro work has reconstituted fusion using VAMP-2, SNAP-25, and syntaxin-1; there is much to learn regarding the behaviors of distinct SNARE complexes. In the past few years, robust heterogeneity in the kinetics and fate of the fusion pore that varies by cell type have been uncovered, suggesting a paradigm shift in how the modes of exocytosis are viewed is warranted. Here, we explore both classic and recent work uncovering the variety of SNAREs and their importance in the development of neurons, as well as historical and newly proposed modes of exocytosis, their regulation, and proteins involved in the regulation of fusion kinetics.
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Affiliation(s)
- Fabio L. Urbina
- Department of Cell Biology and Physiology, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
| | - Stephanie L. Gupton
- Department of Cell Biology and Physiology, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
- UNC Neuroscience Center, Chapel Hill, NC, United States
- UNC Lineberger Comprehensive Cancer Center, Chapel Hill, NC, United States
- Carolina Institute for Developmental Disabilities, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
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49
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Nath VR, Mishra S, Basak B, Trivedi D, Raghu P. Extended synaptotagmin regulates membrane contact site structure and lipid transfer function in vivo. EMBO Rep 2020; 21:e50264. [PMID: 32716137 DOI: 10.15252/embr.202050264] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2020] [Revised: 06/12/2020] [Accepted: 06/22/2020] [Indexed: 12/20/2022] Open
Abstract
Inter-organelle communication between closely apposed membranes is proposed at membrane contact sites (MCS). However, the regulation of MCS structure and their functional relevance in vivo remain debated. The extended synaptotagmins (Esyt) are evolutionarily conserved proteins proposed to function at MCS. However, loss of all three Esyts in yeast or mammals shows minimal phenotypes questioning the functional importance of Esyt. We report that in Drosophila photoreceptors, MCS number is regulated by PLCβ activity. Photoreceptors of a null allele of Drosophila extended synaptotagmin (dEsyt) show loss of ER-PM MCS. Loss of dEsyt results in mislocalization of RDGB, an MCS localized lipid transfer protein, required for photoreceptor structure and function, ultimately leading to retinal degeneration. dEsyt depletion enhanced the retinal degeneration, reduced light responses and slower rates of plasma membrane PIP2 resynthesis seen in rdgB mutants. Thus, dEsyt function and PLCβ signaling regulate ER-PM MCS structure and lipid transfer in Drosophila photoreceptors.
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Affiliation(s)
- Vaisaly R Nath
- National Centre for Biological Sciences-TIFR, Bangalore, India.,School of Biotechnology, Amrita Vishwa Vidyapeetham, Amritapuri, Kollam, Kerala, India
| | - Shirish Mishra
- National Centre for Biological Sciences-TIFR, Bangalore, India
| | - Bishal Basak
- National Centre for Biological Sciences-TIFR, Bangalore, India
| | - Deepti Trivedi
- National Centre for Biological Sciences-TIFR, Bangalore, India
| | - Padinjat Raghu
- National Centre for Biological Sciences-TIFR, Bangalore, India
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50
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Zaman MF, Nenadic A, Radojičić A, Rosado A, Beh CT. Sticking With It: ER-PM Membrane Contact Sites as a Coordinating Nexus for Regulating Lipids and Proteins at the Cell Cortex. Front Cell Dev Biol 2020; 8:675. [PMID: 32793605 PMCID: PMC7387695 DOI: 10.3389/fcell.2020.00675] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2020] [Accepted: 07/03/2020] [Indexed: 12/31/2022] Open
Abstract
Membrane contact sites between the cortical endoplasmic reticulum (ER) and the plasma membrane (PM) provide a direct conduit for small molecule transfer and signaling between the two largest membranes of the cell. Contact is established through ER integral membrane proteins that physically tether the two membranes together, though the general mechanism is remarkably non-specific given the diversity of different tethering proteins. Primary tethers including VAMP-associated proteins (VAPs), Anoctamin/TMEM16/Ist2p homologs, and extended synaptotagmins (E-Syts), are largely conserved in most eukaryotes and are both necessary and sufficient for establishing ER-PM association. In addition, other species-specific ER-PM tether proteins impart unique functional attributes to both membranes at the cell cortex. This review distils recent functional and structural findings about conserved and species-specific tethers that form ER-PM contact sites, with an emphasis on their roles in the coordinate regulation of lipid metabolism, cellular structure, and responses to membrane stress.
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Affiliation(s)
- Mohammad F Zaman
- Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, BC, Canada
| | - Aleksa Nenadic
- Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, BC, Canada
| | - Ana Radojičić
- Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, BC, Canada.,Department of Botany, University of British Columbia, Vancouver, BC, Canada
| | - Abel Rosado
- Department of Botany, University of British Columbia, Vancouver, BC, Canada
| | - Christopher T Beh
- Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, BC, Canada.,The Centre for Cell Biology, Development, and Disease, Simon Fraser University, Burnaby, BC, Canada
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