1
|
Greig J, Bates GT, Yin DI, Briant K, Simonetti B, Cullen PJ, Brodsky FM. CHC22 clathrin recruitment to the early secretory pathway requires two-site interaction with SNX5 and p115. EMBO J 2024:10.1038/s44318-024-00198-y. [PMID: 39160272 DOI: 10.1038/s44318-024-00198-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2023] [Revised: 07/15/2024] [Accepted: 07/17/2024] [Indexed: 08/21/2024] Open
Abstract
The two clathrin isoforms, CHC17 and CHC22, mediate separate intracellular transport routes. CHC17 performs endocytosis and housekeeping membrane traffic in all cells. CHC22, expressed most highly in skeletal muscle, shuttles the glucose transporter GLUT4 from the ERGIC (endoplasmic-reticulum-to-Golgi intermediate compartment) directly to an intracellular GLUT4 storage compartment (GSC), from where GLUT4 can be mobilized to the plasma membrane by insulin. Here, molecular determinants distinguishing CHC22 from CHC17 trafficking are defined. We show that the C-terminal trimerization domain of CHC22 interacts with SNX5, which also binds the ERGIC tether p115. SNX5, and the functionally redundant SNX6, are required for CHC22 localization independently of their participation in the endosomal ESCPE-1 complex. In tandem, an isoform-specific patch in the CHC22 N-terminal domain separately mediates binding to p115. This dual mode of clathrin recruitment, involving interactions at both N- and C-termini of the heavy chain, is required for CHC22 targeting to ERGIC membranes to mediate the Golgi-bypass route for GLUT4 trafficking. Interference with either interaction inhibits GLUT4 targeting to the GSC, defining a bipartite mechanism regulating a key pathway in human glucose metabolism.
Collapse
Affiliation(s)
- Joshua Greig
- Structural and Molecular Biology, Division of Biosciences, University College London, London, WC1E 6BT, UK
- Institute of Structural and Molecular Biology, Birkbeck and University College London, London, WC1E 7HX, UK
| | - George T Bates
- Structural and Molecular Biology, Division of Biosciences, University College London, London, WC1E 6BT, UK
- Institute of Structural and Molecular Biology, Birkbeck and University College London, London, WC1E 7HX, UK
| | - Daowen I Yin
- Structural and Molecular Biology, Division of Biosciences, University College London, London, WC1E 6BT, UK
- Institute of Structural and Molecular Biology, Birkbeck and University College London, London, WC1E 7HX, UK
| | - Kit Briant
- Structural and Molecular Biology, Division of Biosciences, University College London, London, WC1E 6BT, UK
- Institute of Structural and Molecular Biology, Birkbeck and University College London, London, WC1E 7HX, UK
| | - Boris Simonetti
- School of Biochemistry, Faculty of Life Sciences, University of Bristol, Bristol, UK
| | - Peter J Cullen
- School of Biochemistry, Faculty of Life Sciences, University of Bristol, Bristol, UK
| | - Frances M Brodsky
- Structural and Molecular Biology, Division of Biosciences, University College London, London, WC1E 6BT, UK.
- Institute of Structural and Molecular Biology, Birkbeck and University College London, London, WC1E 7HX, UK.
| |
Collapse
|
2
|
Liu D, Hu Z, Lu J, Yi C. Redox-Regulated Iron Metabolism and Ferroptosis in Ovarian Cancer: Molecular Insights and Therapeutic Opportunities. Antioxidants (Basel) 2024; 13:791. [PMID: 39061859 PMCID: PMC11274267 DOI: 10.3390/antiox13070791] [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: 05/01/2024] [Revised: 06/21/2024] [Accepted: 06/24/2024] [Indexed: 07/28/2024] Open
Abstract
Ovarian cancer (OC), known for its lethality and resistance to chemotherapy, is closely associated with iron metabolism and ferroptosis-an iron-dependent cell death process, distinct from both autophagy and apoptosis. Emerging evidence suggests that dysregulation of iron metabolism could play a crucial role in OC by inducing an imbalance in the redox system, which leads to ferroptosis, offering a novel therapeutic approach. This review examines how disruptions in iron metabolism, which affect redox balance, impact OC progression, focusing on its essential cellular functions and potential as a therapeutic target. It highlights the molecular interplay, including the role of non-coding RNAs (ncRNAs), between iron metabolism and ferroptosis, and explores their interactions with key immune cells such as macrophages and T cells, as well as inflammation within the tumor microenvironment. The review also discusses how glycolysis-related iron metabolism influences ferroptosis via reactive oxygen species. Targeting these pathways, especially through agents that modulate iron metabolism and ferroptosis, presents promising therapeutic prospects. The review emphasizes the need for deeper insights into iron metabolism and ferroptosis within the redox-regulated system to enhance OC therapy and advocates for continued research into these mechanisms as potential strategies to combat OC.
Collapse
Affiliation(s)
- Dan Liu
- Department of Obstetrics and Gynecology, The First Affiliated Hospital, Yangtze University, Jingzhou 434000, China; (D.L.); (Z.H.)
- Hubei Provincial Clinical Research Center for Personalized Diagnosis and Treatment of Cancer, Jingzhou 434000, China
| | - Zewen Hu
- Department of Obstetrics and Gynecology, The First Affiliated Hospital, Yangtze University, Jingzhou 434000, China; (D.L.); (Z.H.)
- Hubei Provincial Clinical Research Center for Personalized Diagnosis and Treatment of Cancer, Jingzhou 434000, China
| | - Jinzhi Lu
- Hubei Provincial Clinical Research Center for Personalized Diagnosis and Treatment of Cancer, Jingzhou 434000, China
- Department of Laboratory Medicine, The First Affiliated Hospital, Yangtze University, Jingzhou 434000, China
| | - Cunjian Yi
- Department of Obstetrics and Gynecology, The First Affiliated Hospital, Yangtze University, Jingzhou 434000, China; (D.L.); (Z.H.)
- Hubei Provincial Clinical Research Center for Personalized Diagnosis and Treatment of Cancer, Jingzhou 434000, China
| |
Collapse
|
3
|
Wang X, Xie Y, Fan X, Wu X, Wang D, Zhu L. Intermittent hypoxia training enhances Aβ endocytosis by plaque associated microglia via VPS35-dependent TREM2 recycling in murine Alzheimer's disease. Alzheimers Res Ther 2024; 16:121. [PMID: 38831312 PMCID: PMC11145795 DOI: 10.1186/s13195-024-01489-6] [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: 02/06/2024] [Accepted: 05/27/2024] [Indexed: 06/05/2024]
Abstract
BACKGROUND Beta-amyloid (Aβ) deposition in the brain parenchyma is a crucial initiating step in the amyloid cascade hypothesis of Alzheimer's disease (AD) pathology. Furthermore, dysfunction of plaque-associated microglia, also known as disease-associated microglia (DAM) has been reported to accelerate Aβ deposition and cognitive impairment. Our previous research demonstrated that intermittent hypoxia training (IHT) improved AD pathology by upregulating autophagy in DAM, thereby enhancing oligomeric Aβ (oAβ) clearance. Considering that oAβ internalization is the initial stage of oAβ clearance, this study focused on the IHT mechanism involved in upregulating Aβ uptake by DAM. METHODS IHT was administered to 8-month-old APP/PS1 mice or 6-month-old microglial vacuolar protein sorting 35 (VPS35) knockout mice in APP/PS1 background (MG VPS35 KO: APP/PS1) for 28 days. After the IHT, the spatial learning-memory capacity of the mice was assessed. Additionally, AD pathology was determined by estimating the nerve fiber and synapse density, Aβ plaque deposition, and Aβ load in the brain. A model of Aβ-exposed microglia was constructed and treated with IHT to explore the related mechanism. Finally, triggering receptor expressed on myeloid cells 2 (TREM2) intracellular recycling and Aβ internalization were measured using a fluorescence tracing technique. RESULTS Our results showed that IHT ameliorated cognitive function and Aβ pathology. In particular, IHT enhanced Aβ endocytosis by augmenting the intracellular transport function of microglial TREM2, thereby contributing to Aβ clearance. Furthermore, IHT specifically upregulated VPS35 in DAM, the primary cause for the enhanced intracellular recycling of TREM2. IHT lost ameliorative effect on Aβ pathology in MG VPS35 KO: APP/PS1 mice brain. Lastly, the IHT mechanism of VPS35 upregulation in DAM was mediated by the transcriptional regulation of VPS35 by transcription factor EB (TFEB). CONCLUSION IHT enhances Aβ endocytosis in DAM by upregulating VPS35-dependent TREM2 recycling, thereby facilitating oAβ clearance and mitigation of Aβ pathology. Moreover, the transcriptional regulation of VPS35 by TFEB demonstrates a close link between endocytosis and autophagy in microglia. Our study further elucidates the IHT mechanism in improving AD pathology and provides evidence supporting the potential application of IHT as a complementary therapy for AD.
Collapse
Affiliation(s)
- Xueting Wang
- Institute of Special Environmental Medicine, Co-Innovation Center of Neuroregeneration, Nantong University, No.9, Seyuan Road, Chongchuan District, Nantong, Jiangsu, 226009, China.
| | - Yuqi Xie
- Institute of Special Environmental Medicine, Co-Innovation Center of Neuroregeneration, Nantong University, No.9, Seyuan Road, Chongchuan District, Nantong, Jiangsu, 226009, China
| | - Xiaoyang Fan
- Institute of Special Environmental Medicine, Co-Innovation Center of Neuroregeneration, Nantong University, No.9, Seyuan Road, Chongchuan District, Nantong, Jiangsu, 226009, China
| | - Xiaomei Wu
- Institute of Special Environmental Medicine, Co-Innovation Center of Neuroregeneration, Nantong University, No.9, Seyuan Road, Chongchuan District, Nantong, Jiangsu, 226009, China
| | - Dan Wang
- Institute of Special Environmental Medicine, Co-Innovation Center of Neuroregeneration, Nantong University, No.9, Seyuan Road, Chongchuan District, Nantong, Jiangsu, 226009, China
| | - Li Zhu
- Institute of Special Environmental Medicine, Co-Innovation Center of Neuroregeneration, Nantong University, No.9, Seyuan Road, Chongchuan District, Nantong, Jiangsu, 226009, China.
| |
Collapse
|
4
|
Clippinger AK, Naismith TV, Yoo W, Jansen S, Kast DJ, Hanson PI. IST1 regulates select recycling pathways. Traffic 2024; 25:e12921. [PMID: 37926552 PMCID: PMC11027954 DOI: 10.1111/tra.12921] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2022] [Revised: 08/21/2023] [Accepted: 09/23/2023] [Indexed: 11/07/2023]
Abstract
ESCRTs (Endosomal Sorting Complex Required for Transports) are a modular set of protein complexes with membrane remodeling activities that include the formation and release of intraluminal vesicles (ILVs) to generate multivesicular endosomes. While most of the 12 ESCRT-III proteins are known to play roles in ILV formation, IST1 has been associated with a wider range of endosomal remodeling events. Here, we extend previous studies of IST1 function in endosomal trafficking and confirm that IST1, along with its binding partner CHMP1B, contributes to scission of early endosomal carriers. Functionally, depleting IST1 impaired delivery of transferrin receptor from early/sorting endosomes to the endocytic recycling compartment and instead increased its rapid recycling to the plasma membrane via peripheral endosomes enriched in the clathrin adaptor AP-1. IST1 is also important for export of mannose 6-phosphate receptor from early/sorting endosomes. Examination of IST1 binding partners on endosomes revealed that IST1 interacts with the MIT domain-containing sorting nexin SNX15, a protein previously reported to regulate endosomal recycling. Our kinetic and spatial analyses establish that SNX15 and IST1 occupy a clathrin-containing subdomain on the endosomal perimeter distinct from those previously implicated in cargo retrieval or degradation. Using live-cell microscopy, we see that SNX15 and CHMP1B alternately recruit IST1 to this subdomain or the base of endosomal tubules. These findings indicate that IST1 contributes to a subset of recycling pathways from the early/sorting endosome.
Collapse
Affiliation(s)
- Amy K Clippinger
- Department of Cell Biology and Physiology, Washington University in St. Louis, St. Louis, Missouri, USA
| | - Teresa V Naismith
- Department of Cell Biology and Physiology, Washington University in St. Louis, St. Louis, Missouri, USA
| | - Wonjin Yoo
- Department of Biological Chemistry, University of Michigan Medical School, Ann Arbor, Michigan, USA
| | - Silvia Jansen
- Department of Cell Biology and Physiology, Washington University in St. Louis, St. Louis, Missouri, USA
| | - David J Kast
- Department of Cell Biology and Physiology, Washington University in St. Louis, St. Louis, Missouri, USA
| | - Phyllis I Hanson
- Department of Cell Biology and Physiology, Washington University in St. Louis, St. Louis, Missouri, USA
- Department of Biological Chemistry, University of Michigan Medical School, Ann Arbor, Michigan, USA
| |
Collapse
|
5
|
Clippinger AK, Naismith TV, Yoo W, Jansen S, Kast D, Hanson PI. IST1 regulates select endosomal recycling pathways. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.07.31.551359. [PMID: 37577466 PMCID: PMC10418098 DOI: 10.1101/2023.07.31.551359] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/15/2023]
Abstract
ESCRTs (Endosomal Sorting Complex Required for Transport) are a modular set of protein complexes with membrane remodeling activities that include the formation and release of intralumenal vesicles (ILVs) to generate multivesicular endosomes. While most of the 12 ESCRT-III proteins are known to play roles in ILV formation, IST1 has been associated with a wider range of endosomal remodeling events. Here, we extend previous studies of IST1 function in endosomal trafficking and confirm that IST1, along with its binding partner CHMP1B, contributes to scission of early endosomal carriers. Depleting IST1 impaired delivery of transferrin receptor from early/sorting endosomes to the endocytic recycling compartment and instead increased its rapid recycling to the plasma membrane via peripheral endosomes enriched in the clathrin adaptor AP-1. IST1 is also important for export of mannose 6-phosphate receptor from early/sorting endosomes. Examination of IST1 binding partners on endosomes revealed that IST1 interacts with the MIT domain-containing sorting nexin SNX15, a protein previously reported to regulate endosomal recycling. Our kinetic and spatial analyses establish that SNX15 and IST1 occupy a clathrin-containing subdomain on the endosomal perimeter distinct from those previously implicated in cargo retrieval or degradation. Using live-cell microscopy we see that SNX15 and CHMP1B alternately recruit IST1 to this subdomain or the base of endosomal tubules. These findings indicate that IST1 contributes to a subset of recycling pathways from the early/sorting endosome.
Collapse
|
6
|
Chen H, Weinberg ZY, Kumar GA, Puthenveedu MA. Vesicle-associated membrane protein 2 is a cargo-selective v-SNARE for a subset of GPCRs. J Cell Biol 2023; 222:e202207070. [PMID: 37022307 PMCID: PMC10082327 DOI: 10.1083/jcb.202207070] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2022] [Revised: 01/26/2023] [Accepted: 03/21/2023] [Indexed: 04/07/2023] Open
Abstract
Vesicle fusion at the plasma membrane is critical for releasing hormones and neurotransmitters and for delivering the cognate G protein-coupled receptors (GPCRs) to the cell surface. The SNARE fusion machinery that releases neurotransmitters has been well characterized. In contrast, the fusion machinery that delivers GPCRs is still unknown. Here, using high-speed multichannel imaging to simultaneously visualize receptors and v-SNAREs in real time in individual fusion events, we identify VAMP2 as a selective v-SNARE for GPCR delivery. VAMP2 was preferentially enriched in vesicles that mediate the surface delivery of μ opioid receptor (MOR), but not other cargos, and was required selectively for MOR recycling. Interestingly, VAMP2 did not show preferential localization on MOR-containing endosomes, suggesting that v-SNAREs are copackaged with specific cargo into separate vesicles from the same endosomes. Together, our results identify VAMP2 as a cargo-selective v-SNARE and suggest that surface delivery of specific GPCRs is mediated by distinct fusion events driven by distinct SNARE complexes.
Collapse
Affiliation(s)
- Hao Chen
- Department of Pharmacology, University of MichiganMedical School, Ann Arbor, MI, USA
| | - Zara Y. Weinberg
- Department of Pharmacology, University of MichiganMedical School, Ann Arbor, MI, USA
| | - G. Aditya Kumar
- Department of Pharmacology, University of MichiganMedical School, Ann Arbor, MI, USA
| | | |
Collapse
|
7
|
Wang H, Cheng Q, Bao L, Li M, Chang K, Yi X. Cytoprotective Role of Heme Oxygenase-1 in Cancer Chemoresistance: Focus on Antioxidant, Antiapoptotic, and Pro-Autophagy Properties. Antioxidants (Basel) 2023; 12:1217. [PMID: 37371947 DOI: 10.3390/antiox12061217] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2023] [Revised: 05/23/2023] [Accepted: 05/25/2023] [Indexed: 06/29/2023] Open
Abstract
Chemoresistance remains the foremost challenge in cancer therapy. Targeting reactive oxygen species (ROS) manipulation is a promising strategy in cancer treatment since tumor cells present high levels of intracellular ROS, which makes them more vulnerable to further ROS elevation than normal cells. Nevertheless, dynamic redox evolution and adaptation of tumor cells are capable of counteracting therapy-induced oxidative stress, which leads to chemoresistance. Hence, exploring the cytoprotective mechanisms of tumor cells is urgently needed to overcome chemoresistance. Heme oxygenase-1 (HO-1), a rate-limiting enzyme of heme degradation, acts as a crucial antioxidant defense and cytoprotective molecule in response to cellular stress. Recently, emerging evidence indicated that ROS detoxification and oxidative stress tolerance owing to the antioxidant function of HO-1 contribute to chemoresistance in various cancers. Enhanced HO-1 expression or enzymatic activity was revealed to promote apoptosis resistance and activate protective autophagy, which also involved in the development of chemoresistance. Moreover, inhibition of HO-1 in multiple cancers was identified to reversing chemoresistance or improving chemosensitivity. Here, we summarize the most recent advances regarding the antioxidant, antiapoptotic, and pro-autophagy properties of HO-1 in mediating chemoresistance, highlighting HO-1 as a novel target for overcoming chemoresistance and improving the prognosis of cancer patients.
Collapse
Affiliation(s)
- Huan Wang
- Department of Gynecology, Hospital of Obstetrics and Gynecology, Fudan University, Shanghai 200011, China
- Shanghai Key Laboratory of Female Reproductive Endocrine Related Diseases, Shanghai 200011, China
| | - Qi Cheng
- Department of Gynecology, Hospital of Obstetrics and Gynecology, Fudan University, Shanghai 200011, China
- Shanghai Key Laboratory of Female Reproductive Endocrine Related Diseases, Shanghai 200011, China
| | - Lingjie Bao
- Department of Gynecology, Hospital of Obstetrics and Gynecology, Fudan University, Shanghai 200011, China
- Shanghai Key Laboratory of Female Reproductive Endocrine Related Diseases, Shanghai 200011, China
| | - Mingqing Li
- Department of Gynecology, Hospital of Obstetrics and Gynecology, Fudan University, Shanghai 200011, China
- Shanghai Key Laboratory of Female Reproductive Endocrine Related Diseases, Shanghai 200011, China
| | - Kaikai Chang
- Department of Gynecology, Hospital of Obstetrics and Gynecology, Fudan University, Shanghai 200011, China
- Shanghai Key Laboratory of Female Reproductive Endocrine Related Diseases, Shanghai 200011, China
| | - Xiaofang Yi
- Department of Gynecology, Hospital of Obstetrics and Gynecology, Fudan University, Shanghai 200011, China
- Shanghai Key Laboratory of Female Reproductive Endocrine Related Diseases, Shanghai 200011, China
| |
Collapse
|
8
|
El-Bazzal L, Ghata A, Estève C, Gadacha J, Quintana P, Castro C, Roeckel-Trévisiol N, Lembo F, Lenfant N, Mégarbané A, Borg JP, Lévy N, Bartoli M, Poitelon Y, Roubertoux PL, Delague V, Bernard-Marissal N. Imbalance of NRG1-ERBB2/3 signalling underlies altered myelination in Charcot-Marie-Tooth disease 4H. Brain 2023; 146:1844-1858. [PMID: 36314052 PMCID: PMC10151191 DOI: 10.1093/brain/awac402] [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: 03/25/2022] [Revised: 08/30/2022] [Accepted: 10/02/2022] [Indexed: 11/12/2022] Open
Abstract
Charcot-Marie-Tooth (CMT) disease is one of the most common inherited neurological disorders, affecting either axons from the motor and/or sensory neurons or Schwann cells of the peripheral nervous system (PNS) and caused by more than 100 genes. We previously identified mutations in FGD4 as responsible for CMT4H, an autosomal recessive demyelinating form of CMT disease. FGD4 encodes FRABIN, a GDP/GTP nucleotide exchange factor, particularly for the small GTPase Cdc42. Remarkably, nerves from patients with CMT4H display excessive redundant myelin figures called outfoldings that arise from focal hypermyelination, suggesting that FRABIN could play a role in the control of PNS myelination. To gain insights into the role of FGD4/FRABIN in Schwann cell myelination, we generated a knockout mouse model (Fgd4SC-/-), with conditional ablation of Fgd4 in Schwann cells. We show that the specific deletion of FRABIN in Schwann cells leads to aberrant myelination in vitro, in dorsal root ganglia neuron/Schwann cell co-cultures, as well as in vivo, in distal sciatic nerves from Fgd4SC-/- mice. We observed that those myelination defects are related to an upregulation of some interactors of the NRG1 type III/ERBB2/3 signalling pathway, which is known to ensure a proper level of myelination in the PNS. Based on a yeast two-hybrid screen, we identified SNX3 as a new partner of FRABIN, which is involved in the regulation of endocytic trafficking. Interestingly, we showed that the loss of FRABIN impairs endocytic trafficking, which may contribute to the defective NRG1 type III/ERBB2/3 signalling and myelination. Using RNA-Seq, in vitro, we identified new potential effectors of the deregulated pathways, such as ERBIN, RAB11FIP2 and MAF, thereby providing cues to understand how FRABIN contributes to proper ERBB2 trafficking or even myelin membrane addition through cholesterol synthesis. Finally, we showed that the re-establishment of proper levels of the NRG1 type III/ERBB2/3 pathway using niacin treatment reduces myelin outfoldings in nerves of CMT4H mice. Overall, our work reveals a new role of FRABIN in the regulation of NRG1 type III/ERBB2/3 NRG1signalling and myelination and opens future therapeutic strategies based on the modulation of the NRG1 type III/ERBB2/3 pathway to reduce CMT4H pathology and more generally other demyelinating types of CMT disease.
Collapse
Affiliation(s)
- Lara El-Bazzal
- Aix Marseille Univ, INSERM, MMG, U 1251, Marseille, France
| | - Adeline Ghata
- Aix Marseille Univ, INSERM, MMG, U 1251, Marseille, France
| | | | - Jihane Gadacha
- Aix Marseille Univ, INSERM, MMG, U 1251, Marseille, France
| | | | | | | | - Frédérique Lembo
- Aix Marseille Univ, INSERM, CNRS, CRCM, Institut Paoli-Calmettes, Marseille, France
| | | | - André Mégarbané
- Department of Human Genetics, Gilbert and Rose-Marie Chagoury School of Medicine, Lebanese American University, Beirut, Lebanon
| | - Jean-Paul Borg
- Aix Marseille Univ, INSERM, CNRS, CRCM, Institut Paoli-Calmettes, Marseille, France
| | - Nicolas Lévy
- Aix Marseille Univ, INSERM, MMG, U 1251, Marseille, France
| | - Marc Bartoli
- Aix Marseille Univ, INSERM, MMG, U 1251, Marseille, France
| | - Yannick Poitelon
- Department of Neuroscience and Experimental Therapeutics, Albany Medical College, Albany, NY, USA
| | | | | | | |
Collapse
|
9
|
Multifaceted Roles of Retromer in EGFR Trafficking and Signaling Activation. Cells 2022; 11:cells11213358. [DOI: 10.3390/cells11213358] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2022] [Revised: 10/21/2022] [Accepted: 10/21/2022] [Indexed: 11/16/2022] Open
Abstract
Mammalian retromer complex contributes to multiple early endosome-associated trafficking pathways whose origins are dependent on which sorting nexin (SNX) they are complexed with. In an attempt to dissect out the contribution of individual retromer–SNX complexes, we examined the trafficking of EGFR in detail within a series of KO cell line models. We demonstrated that the depletion of retromer subunit Vps35 leads to decreased EGFR protein levels in resting cells with enhanced association of EGFR with lysosomal compartments. Compared to control cells, the addition of EGF to Vps35 KO cells resulted in a reduced rate of EGFR degradation; AKT activation and cell prolferation rates were elevated, while ERK activation remained relatively unchanged. These observations are consistent with a prolonged temporal association of EGFR within early endosomes due to the inefficiency of early endosome-associated protein trafficking pathways or organelle maturation due to retromer absence. We did not fully delineate the discrete contributions from retromer-associated SNXs to the phenotypes observed from retromer Vps35 depletion. While each of the knock-outs of SNX1/2, SNX3, or SNX27 promotes the enhanced association of EGFR with early endosomal compartments, only the decreased EGF-mediated EGFR degradation was observed in SNX1/2 dKO cells, while the enhanced AKT activation was only increased in SNX3 KO or SNX27 KO cells. Despite this, each of the knock-outs showed increased EGF-stimulated cell proliferation rates.
Collapse
|
10
|
HRG-9 homologues regulate haem trafficking from haem-enriched compartments. Nature 2022; 610:768-774. [PMID: 36261532 PMCID: PMC9810272 DOI: 10.1038/s41586-022-05347-z] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2021] [Accepted: 09/14/2022] [Indexed: 02/05/2023]
Abstract
Haem is an iron-containing tetrapyrrole that is critical for a variety of cellular and physiological processes1-3. Haem binding proteins are present in almost all cellular compartments, but the molecular mechanisms that regulate the transport and use of haem within the cell remain poorly understood2,3. Here we show that haem-responsive gene 9 (HRG-9) (also known as transport and Golgi organization 2 (TANGO2)) is an evolutionarily conserved haem chaperone with a crucial role in trafficking haem out of haem storage or synthesis sites in eukaryotic cells. Loss of Caenorhabditis elegans hrg-9 and its paralogue hrg-10 results in the accumulation of haem in lysosome-related organelles, the haem storage site in worms. Similarly, deletion of the hrg-9 homologue TANGO2 in yeast and mammalian cells induces haem overload in mitochondria, the site of haem synthesis. We demonstrate that TANGO2 binds haem and transfers it from cellular membranes to apo-haemoproteins. Notably, homozygous tango2-/- zebrafish larvae develop pleiotropic symptoms including encephalopathy, cardiac arrhythmia and myopathy, and die during early development. These defects partially resemble the symptoms of human TANGO2-related metabolic encephalopathy and arrhythmias, a hereditary disease caused by mutations in TANGO24-8. Thus, the identification of HRG-9 as an intracellular haem chaperone provides a biological basis for exploring the aetiology and treatment of TANGO2-related disorders.
Collapse
|
11
|
New Players in Neuronal Iron Homeostasis: Insights from CRISPRi Studies. Antioxidants (Basel) 2022; 11:antiox11091807. [PMID: 36139881 PMCID: PMC9495848 DOI: 10.3390/antiox11091807] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2022] [Revised: 09/02/2022] [Accepted: 09/07/2022] [Indexed: 11/16/2022] Open
Abstract
Selective regional iron accumulation is a hallmark of several neurodegenerative diseases, including Alzheimer’s disease and Parkinson’s disease. The underlying mechanisms of neuronal iron dyshomeostasis have been studied, mainly in a gene-by-gene approach. However, recent high-content phenotypic screens using CRISPR/Cas9-based gene perturbations allow for the identification of new pathways that contribute to iron accumulation in neuronal cells. Herein, we perform a bioinformatic analysis of a CRISPR-based screening of lysosomal iron accumulation and the functional genomics of human neurons derived from induced pluripotent stem cells (iPSCs). Consistent with previous studies, we identified mitochondrial electron transport chain dysfunction as one of the main mechanisms triggering iron accumulation, although we substantially expanded the gene set causing this phenomenon, encompassing mitochondrial complexes I to IV, several associated assembly factors, and coenzyme Q biosynthetic enzymes. Similarly, the loss of numerous genes participating through the complete macroautophagic process elicit iron accumulation. As a novelty, we found that the impaired synthesis of glycophosphatidylinositol (GPI) and GPI-anchored protein trafficking also trigger iron accumulation in a cell-autonomous manner. Finally, the loss of critical components of the iron transporters trafficking machinery, including MON2 and PD-associated gene VPS35, also contribute to increased neuronal levels. Our analysis suggests that neuronal iron accumulation can arise from the dysfunction of an expanded, previously uncharacterized array of molecular pathways.
Collapse
|
12
|
Chen M, Zhang Y, Jiang K, Wang W, Feng H, Zhen R, Moo C, Zhang Z, Shi J, Chen C. Grab regulates transferrin receptor recycling and iron uptake in developing erythroblasts. Blood 2022; 140:1145-1155. [PMID: 35820059 DOI: 10.1182/blood.2021015189] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2021] [Accepted: 06/25/2022] [Indexed: 11/20/2022] Open
Abstract
Developing erythroblasts acquire massive amounts of iron through the transferrin (Tf) cycle, which involves endocytosis, sorting, and recycling of the Tf-Tf receptor (Tfrc) complex. Previous studies on the hemoglobin-deficit (hbd) mouse have shown that the exocyst complex is indispensable for the Tfrc recycling; however, the precise mechanism underlying the efficient exocytosis and recycling of Tfrc in erythroblasts remains unclear. Here, we identify the guanine nucleotide exchange factor Grab as a critical regulator of the Tf cycle and iron metabolism during erythropoiesis. Grab is highly expressed in differentiating erythroblasts. Loss of Grab diminishes the Tfrc recycling and iron uptake, leading to hemoglobinization defects in mouse primary erythroblasts, mammalian erythroleukemia cells, and zebrafish embryos. These defects can be alleviated by supplementing iron together with hinokitiol, a small-molecule natural compound that can mediate iron transport independent of the Tf cycle. Mechanistically, Grab regulates the exocytosis of Tfrc-associated vesicles by activating the GTPase Rab8, which subsequently promotes the recruitment of the exocyst complex and vesicle exocytosis. Our results reveal a critical role for Grab in regulating the Tf cycle and provide new insights into iron homeostasis and erythropoiesis.
Collapse
Affiliation(s)
- Mengying Chen
- Ministry of Education Key Laboratory of Biosystems Homeostasis and Protection, Institute of Cell and Developmental Biology, College of Life Sciences, Zhejiang University, Hangzhou, China
| | - Yuhan Zhang
- Ministry of Education Key Laboratory of Biosystems Homeostasis and Protection, Institute of Cell and Developmental Biology, College of Life Sciences, Zhejiang University, Hangzhou, China
| | - Kailun Jiang
- Ministry of Education Key Laboratory of Biosystems Homeostasis and Protection, Institute of Cell and Developmental Biology, College of Life Sciences, Zhejiang University, Hangzhou, China
| | - Weixi Wang
- Department of Biomedical Sciences, City University of Hong Kong, Hong Kong, China
| | - He Feng
- Ministry of Education Key Laboratory of Biosystems Homeostasis and Protection, Institute of Cell and Developmental Biology, College of Life Sciences, Zhejiang University, Hangzhou, China
| | - Ru Zhen
- Ministry of Education Key Laboratory of Biosystems Homeostasis and Protection, Institute of Cell and Developmental Biology, College of Life Sciences, Zhejiang University, Hangzhou, China
| | - Chingyee Moo
- Department of Biomedical Sciences, City University of Hong Kong, Hong Kong, China
| | - Zhuonan Zhang
- Ministry of Education Key Laboratory of Biosystems Homeostasis and Protection, Institute of Cell and Developmental Biology, College of Life Sciences, Zhejiang University, Hangzhou, China
| | - Jiahai Shi
- Synthetic Biology Translational Research Programs, Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore; and
| | - Caiyong Chen
- Ministry of Education Key Laboratory of Biosystems Homeostasis and Protection, Institute of Cell and Developmental Biology, College of Life Sciences, Zhejiang University, Hangzhou, China
- Cancer Center, Zhejiang University, Hangzhou, China
| |
Collapse
|
13
|
Mahmutefendić Lučin H, Blagojević Zagorac G, Marcelić M, Lučin P. Host Cell Signatures of the Envelopment Site within Beta-Herpes Virions. Int J Mol Sci 2022; 23:9994. [PMID: 36077391 PMCID: PMC9456339 DOI: 10.3390/ijms23179994] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2022] [Revised: 08/22/2022] [Accepted: 08/24/2022] [Indexed: 11/26/2022] Open
Abstract
Beta-herpesvirus infection completely reorganizes the membrane system of the cell. This system is maintained by the spatiotemporal arrangement of more than 3000 cellular proteins that continuously adapt the configuration of membrane organelles according to cellular needs. Beta-herpesvirus infection establishes a new configuration known as the assembly compartment (AC). The AC membranes are loaded with virus-encoded proteins during the long replication cycle and used for the final envelopment of the newly formed capsids to form infectious virions. The identity of the envelopment membranes is still largely unknown. Electron microscopy and immunofluorescence studies suggest that the envelopment occurs as a membrane wrapping around the capsids, similar to the growth of phagophores, in the area of the AC with the membrane identities of early/recycling endosomes and the trans-Golgi network. During wrapping, host cell proteins that define the identity and shape of these membranes are captured along with the capsids and incorporated into the virions as host cell signatures. In this report, we reviewed the existing information on host cell signatures in human cytomegalovirus (HCMV) virions. We analyzed the published proteomes of the HCMV virion preparations that identified a large number of host cell proteins. Virion purification methods are not yet advanced enough to separate all of the components of the rich extracellular material, including the large amounts of non-vesicular extracellular particles (NVEPs). Therefore, we used the proteomic data from large and small extracellular vesicles (lEVs and sEVs) and NVEPs to filter out the host cell proteins identified in the viral proteomes. Using these filters, we were able to narrow down the analysis of the host cell signatures within the virions and determine that envelopment likely occurs at the membranes derived from the tubular recycling endosomes. Many of these signatures were also found at the autophagosomes, suggesting that the CMV-infected cell forms membrane organelles with phagophore growth properties using early endosomal host cell machinery that coordinates endosomal recycling.
Collapse
Affiliation(s)
| | | | | | - Pero Lučin
- Department of Physiology, Immunology and Pathophysiology, Faculty of Medicine, University of Rijeka, 51000 Rijeka, Croatia
| |
Collapse
|
14
|
Malik Z, Parveen R, Abass S, Irfan Dar M, Husain SA, Ahmad S. Receptor-Mediated Targeting in Breast Cancer through Solid Lipid Nanoparticles and Its Mechanism. Curr Drug Metab 2022; 23:800-817. [PMID: 35430962 DOI: 10.2174/1389200223666220416213639] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Revised: 02/20/2022] [Accepted: 03/01/2022] [Indexed: 01/05/2023]
Abstract
Nanoparticles have gained prominence in many areas and domains worldwide, such as metallic NP, carbon dots, quantum dots, polymeric NP, nano-suspension, nanocrystals, solid lipid nanoparticles (SLN), etc. and have been applied in the field of medicine as nanomedicine with promising results. Rise in cancer mortality rate has been an issue for a long time with female breast cancer as one of the most detected cancers. No permanent treatment has been developed till date could combat breast cancer with minimum side effects that are not long-lasting as there is no proper technique through which the anticancer drugs can recognize benign or malignant or normal cells that causes systematic toxicity. Advancement in technology has led to the discovery of many biological pathways and mechanisms. Tumor cells or cancer cells overexpress some high-affinity receptors that can be targeted to deliver the anticancer drugs at specific site using these pathways and mechanisms. Solid lipid nanoparticles (SLN) are among some of the excellent drug delivery systems, especially stealth SLN (sSLN). SLN, when conjugated with a ligand (called as sSLN), has affinity and specificity towards a specific receptor, and can deliver the drug in breast cancer cells overexpressing the receptors. Using this technique, various investigations have reported better anti-breast cancer activity than simple SLN (non-conjugated to ligand or no receptor targeting). This review includes the investigations and data on receptor-mediated targeting in breast cancer from 2010 to 2021 by searching different databases. Overall, information on SLN in different cancers is reviewed. In vivo investigations, pharmacokinetics, biodistribution, and stability are discussed to describe the efficacy of sSLN. Investigations included in this review demonstrate that sSLN delivers the drug by overcoming the biological barriers and shows enhanced and better activity than non-conjugated SLN which also verifies that a lesser concentration of drug can show anti-breast cancer activity. The efficacy of medicines could be increased with lower cancer deaths through stealth-SLN. Due to the low cost of synthesis, biocompatibility and easy to formulate, more study is needed in vitro and in vivo so that this novel technique could be utilized in the treatment of human breast cancer.
Collapse
Affiliation(s)
- Zoya Malik
- Human Genetics Laboratory, Department of Biosciences, Jamia Millia Islamia, New Delhi-110025, India.,Bioactive Natural Product Laboratory, School of Pharmaceutical Education and Research, Jamia Hamdard, New Delhi-110062, India
| | - Rabea Parveen
- Human Genetics Laboratory, Department of Biosciences, Jamia Millia Islamia, New Delhi-110025, India.,Bioactive Natural Product Laboratory, School of Pharmaceutical Education and Research, Jamia Hamdard, New Delhi-110062, India
| | - Sageer Abass
- Human Genetics Laboratory, Department of Biosciences, Jamia Millia Islamia, New Delhi-110025, India.,Bioactive Natural Product Laboratory, School of Pharmaceutical Education and Research, Jamia Hamdard, New Delhi-110062, India
| | - Mohammad Irfan Dar
- Bioactive Natural Product Laboratory, School of Pharmaceutical Education and Research, Jamia Hamdard, New Delhi-110062, India.,Proteomics and Bioinformatics Laboratory, Department of Biotechnology, Jamia Millia Islamia, New Delhi-110025, India
| | - Syed Akhtar Husain
- Human Genetics Laboratory, Department of Biosciences, Jamia Millia Islamia, New Delhi-110025, India
| | - Sayeed Ahmad
- Bioactive Natural Product Laboratory, School of Pharmaceutical Education and Research, Jamia Hamdard, New Delhi-110062, India
| |
Collapse
|
15
|
Halcrow PW, Kumar N, Afghah Z, Fischer JP, Khan N, Chen X, Meucci O, Geiger JD. Heterogeneity of ferrous iron-containing endolysosomes and effects of endolysosome iron on endolysosome numbers, sizes, and localization patterns. J Neurochem 2022; 161:69-83. [PMID: 35124818 PMCID: PMC9587899 DOI: 10.1111/jnc.15583] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2021] [Revised: 01/22/2022] [Accepted: 01/31/2022] [Indexed: 11/28/2022]
Abstract
Endolysosomes are key regulators of iron metabolism and are central to iron trafficking and redox signaling. Iron homeostasis is linked to endolysosome acidity and inhibition of endolysosome acidity triggers iron dysregulation. Because of the physiological importance and pathological relevance of ferrous iron (Fe2+ ), we determined levels of Fe2+ specifically and quantitatively in endolysosomes as well as the effects of Fe2+ on endolysosome morphology, distribution patterns, and function. The fluorescence dye FeRhoNox-1 was specific for Fe2+ and localized to endolysosomes in U87MG astrocytoma cells and primary rat cortical neurons; in U87MG cells the endolysosome concentration of Fe2+ ([Fe2+ ]el ) was 50.4 μM in control cells, 73.6 μM in ferric ammonium citrate (FAC) treated cells, and 12.4 μM in cells treated with the iron chelator deferoxamine (DFO). Under control conditions, in primary rat cortical neurons, [Fe2+ ]el was 32.7 μM. Endolysosomes containing the highest levels of Fe2+ were located perinuclearly. Treatment of cells with FAC resulted in endolysosomes that were less acidic, increased in numbers and sizes, and located further from the nucleus; opposite effects were observed for treatments with DFO. Thus, FeRhoNox-1 is a useful probe for the study of endolysosome Fe2+ , and much more work is needed to understand better the physiological significance and pathological relevance of endolysosomes classified according to their heterogeneous iron content Cover Image for this issue: https://doi.org/10.1111/jnc.15396.
Collapse
Affiliation(s)
- Peter W. Halcrow
- Department of Biomedical Sciences, University of North Dakota School of Medicine and Health Sciences, Grand Forks, North Dakota, USA
| | - Nirmal Kumar
- Department of Biomedical Sciences, University of North Dakota School of Medicine and Health Sciences, Grand Forks, North Dakota, USA
| | - Zahra Afghah
- Department of Biomedical Sciences, University of North Dakota School of Medicine and Health Sciences, Grand Forks, North Dakota, USA
| | - Jalyn P. Fischer
- Department of Biomedical Sciences, University of North Dakota School of Medicine and Health Sciences, Grand Forks, North Dakota, USA
| | - Nabab Khan
- Department of Biomedical Sciences, University of North Dakota School of Medicine and Health Sciences, Grand Forks, North Dakota, USA
| | - Xuesong Chen
- Department of Biomedical Sciences, University of North Dakota School of Medicine and Health Sciences, Grand Forks, North Dakota, USA
| | - Olimpia Meucci
- Department of Physiology and Pharmacology, Drexel University College of Medicine, Philadelphia, Pennsylvania, USA
| | - Jonathan D. Geiger
- Department of Biomedical Sciences, University of North Dakota School of Medicine and Health Sciences, Grand Forks, North Dakota, USA
| |
Collapse
|
16
|
Early Endosomal Vps34-Derived Phosphatidylinositol-3-Phosphate Is Indispensable for the Biogenesis of the Endosomal Recycling Compartment. Cells 2022; 11:cells11060962. [PMID: 35326413 PMCID: PMC8946653 DOI: 10.3390/cells11060962] [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: 01/18/2022] [Revised: 02/17/2022] [Accepted: 03/09/2022] [Indexed: 12/29/2022] Open
Abstract
Phosphatidylinositol-3-phosphate (PI3P), a major identity tag of early endosomes (EEs), provides a platform for the recruitment of numerous cellular proteins containing an FYVE or PX domain that is required for PI3P-dependent maturation of EEs. Most of the PI3P in EEs is generated by the activity of Vps34, a catalytic component of class III phosphatidylinositol-3-phosphate kinase (PI3Ks) complex. In this study, we analyzed the role of Vps34-derived PI3P in the EE recycling circuit of unperturbed cells using VPS34-IN1 (IN1), a highly specific inhibitor of Vps34. IN1-mediated PI3P depletion resulted in the rapid dissociation of recombinant FYVE- and PX-containing PI3P-binding modules and endogenous PI3P-binding proteins, including EEA1 and EE sorting nexins. IN1 treatment triggered the rapid restructuring of EEs into a PI3P-independent functional configuration, and after IN1 washout, EEs were rapidly restored to a PI3P-dependent functional configuration. Analysis of the PI3P-independent configuration showed that the Vps34-derived PI3P is not essential for the pre-EE-associated functions and the fast recycling loop of the EE recycling circuit but contributes to EE maturation toward the degradation circuit, as previously shown in Vps34 knockout and knockdown studies. However, our study shows that Vps34-derived PI3P is also essential for the establishment of the Rab11a-dependent pathway, including recycling cargo sorting in this pathway and membrane flux from EEs to the pericentriolar endosomal recycling compartment (ERC). Rab11a endosomes of PI3P-depleted cells expanded and vacuolized outside the pericentriolar area without the acquisition of internalized transferrin (Tf). These endosomes had high levels of FIP5 and low levels of FIP3, suggesting that their maturation was arrested before the acquisition of FIP3. Consequently, Tf-loaded-, Rab11a/FIP5-, and Rab8a-positive endosomes disappeared from the pericentriolar area, implying that PI3P-associated functions are essential for ERC biogenesis. ERC loss was rapidly reversed after IN1 washout, which coincided with the restoration of FIP3 recruitment to Rab11a-positive endosomes and their dynein-dependent migration to the cell center. Thus, our study shows that Vps34-derived PI3P is indispensable in the recycling circuit to maintain the slow recycling pathway and biogenesis of the ERC.
Collapse
|
17
|
Rajasekaran S, Patel D, Witt SN. α-synuclein and phosphoinositide-binding proteins: α-synuclein inhibits the association of PX- but not FYVE-containing proteins with vesicles in vivo. Biochem Biophys Res Commun 2022; 603:7-12. [PMID: 35263697 PMCID: PMC8967794 DOI: 10.1016/j.bbrc.2022.01.101] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2022] [Accepted: 01/26/2022] [Indexed: 11/02/2022]
Abstract
By an unknown mechanism, alpha-synuclein (α-syn) inhibits autophagy in yeast and human cells. Herein, using the yeast Saccharomyces cerevisiae, we tested the hypothesis that α-syn disrupts autophagy by inhibiting the required association of sorting nexin 4 (Snx4) with phagophores. Snx4 contains a phox (PX) homology domain that selectively binds membranes enriched in phosphatidylinositol 3-phosphate (PI3P). Using fluorescence microscopy, we show that upon nitrogen starvation, 70% of the cells exhibited green puncta (phagophores); whereas identically treated cells expressing α-syn exhibited a significantly lower percentage of cells (30%) with such puncta. Our interpretation is that α-syn outcompetes Snx4 for binding to membranes enriched in PI3P, resulting in fewer phagophores and consequently inefficient induction of autophagy. As a control, we tested whether α-syn disrupts the binding of Vps27-GFP to late endosomes/multivesicular bodies (MVBs). Vps27 contains a PI3P-binding domain called FYVE. α-Syn did not disrupt the binding of Vps27-GFP to late endosomes. α-Syn likely inhibits the binding of PX- but not FYVE-containing proteins to PI3P because FYVE domains bind more than two-orders of magnitude tighter than PX domains. We propose that in all cells, whether yeast or human, α-syn has the potential to inhibit protein trafficking pathways that are dependent on PX-domain proteins such as sorting nexins.
Collapse
Affiliation(s)
- Santhanasabapathy Rajasekaran
- Department of Biochemistry and Molecular Biology, Louisiana State University Health Sciences Center, Shreveport, LA, USA
| | - Dhaval Patel
- Department of Biochemistry and Molecular Biology, Louisiana State University Health Sciences Center, Shreveport, LA, USA
| | - Stephan N Witt
- Department of Biochemistry and Molecular Biology, Louisiana State University Health Sciences Center, Shreveport, LA, USA.
| |
Collapse
|
18
|
Portilla Y, Mulens-Arias V, Paradela A, Ramos-Fernández A, Pérez-Yagüe S, Morales MP, Barber DF. The surface coating of iron oxide nanoparticles drives their intracellular trafficking and degradation in endolysosomes differently depending on the cell type. Biomaterials 2022; 281:121365. [PMID: 35038611 DOI: 10.1016/j.biomaterials.2022.121365] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2021] [Revised: 12/15/2021] [Accepted: 01/04/2022] [Indexed: 12/13/2022]
Abstract
Magnetic nanoparticles (MNPs) are potential theranostic tools that are biodegraded through different endocytic pathways. However, little is known about the endolysosomal network through which MNPs transit and the influence of the surface coating in this process. Here, we studied the intracellular transit of two MNPs with identical iron oxide core size but with two distinct coatings: 3-aminopropyl-trietoxysilane (APS) and dimercaptosuccinic acid (DMSA). Using endolysosomal markers and a high throughput analysis of the associated proteome, we tracked the MNPs intracellularly in two different mouse cell lines, RAW264.7 (macrophages) and Pan02 (tumor cells). We did not detect differences in the MNP trafficking kinetics nor in the MNP-containing endolysosome phenotype in Pan02 cells. Nonetheless, DMSA-MNPs transited at slower rate than APS-MNPs in macrophages as measured by MNP accumulation in Rab7+ endolysosomes. Macrophage DMSA-MNP-containing endolysosomes had a higher percentage of lytic enzymes and catalytic proteins than their APS-MNP counterparts, concomitantly with a V-type ATPase enrichment, suggesting an acidic nature. Consequently, more autophagic vesicles are induced by DMSA-MNPs in macrophages, enhancing the expression of iron metabolism-related genes and proteins. Therefore, unlike Pan02 cells, the MNP coating appears to influence the intracellular trafficking rate and the endolysosome nature in macrophages. These results highlight how the MNP coating can determine the nanoparticle intracellular fate and biodegradation in a cell-type bias.
Collapse
Affiliation(s)
- Yadileiny Portilla
- Department of Immunology and Oncology and Nanobiomedicine Initiative, Centro Nacional de Biotecnología (CNB-CSIC), Darwin 3, 28049, Madrid, Spain
| | - Vladimir Mulens-Arias
- Department of Immunology and Oncology and Nanobiomedicine Initiative, Centro Nacional de Biotecnología (CNB-CSIC), Darwin 3, 28049, Madrid, Spain; Current address: Integrative Biomedical Materials and Nanomedicine Lab, Department of Experimental and Health Sciences (DCEXS), Pompeu Fabra University, PRBB, Carrer Doctor Aiguader 88, 08003, Barcelona, Spain
| | - Alberto Paradela
- Proteomics Facility, Centro Nacional de Biotecnología (CNB-CSIC), Darwin 3, 28049, Madrid, Spain
| | - Antonio Ramos-Fernández
- Proteomics Facility, Centro Nacional de Biotecnología (CNB-CSIC), Darwin 3, 28049, Madrid, Spain
| | - Sonia Pérez-Yagüe
- Department of Immunology and Oncology and Nanobiomedicine Initiative, Centro Nacional de Biotecnología (CNB-CSIC), Darwin 3, 28049, Madrid, Spain
| | - M Puerto Morales
- Department of Energy, Environment and Health, Instituto de Ciencia de Materiales de Madrid (ICMM-CSIC), Sor Juana Inés de la Cruz 3, 28049, Madrid, Spain
| | - Domingo F Barber
- Department of Immunology and Oncology and Nanobiomedicine Initiative, Centro Nacional de Biotecnología (CNB-CSIC), Darwin 3, 28049, Madrid, Spain.
| |
Collapse
|
19
|
Zeidan RS, Han SM, Leeuwenburgh C, Xiao R. Iron homeostasis and organismal aging. Ageing Res Rev 2021; 72:101510. [PMID: 34767974 DOI: 10.1016/j.arr.2021.101510] [Citation(s) in RCA: 48] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2021] [Revised: 11/02/2021] [Accepted: 11/02/2021] [Indexed: 12/21/2022]
Abstract
Iron is indispensable for normal body functions across species because of its critical roles in red blood cell function and many essential proteins and enzymes required for numerous physiological processes. Regulation of iron homeostasis is an intricate process involving multiple modulators at the systemic, cellular, and molecular levels. Interestingly, emerging evidence has demonstrated that many modulators of iron homeostasis contribute to organismal aging and longevity. On the other hand, the age-related dysregulation of iron homeostasis is often associated with multiple age-related pathologies including bone resorption and neurodegenerative diseases such as Alzheimer's disease. Thus, a thorough understanding on the interconnections between systemic and cellular iron balance and organismal aging may help decipher the etiologies of multiple age-related diseases, which could ultimately lead to developing therapeutic strategies to delay aging and treat various age-related diseases. Here we present the current understanding on the mechanisms of iron homeostasis. We also discuss the impacts of aging on iron homeostatic processes and how dysregulated iron metabolism may affect aging and organismal longevity.
Collapse
|
20
|
Using the Zebrafish as a Genetic Model to Study Erythropoiesis. Int J Mol Sci 2021; 22:ijms221910475. [PMID: 34638816 PMCID: PMC8508994 DOI: 10.3390/ijms221910475] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2021] [Revised: 09/18/2021] [Accepted: 09/25/2021] [Indexed: 11/30/2022] Open
Abstract
Vertebrates generate mature red blood cells (RBCs) via a highly regulated, multistep process called erythropoiesis. Erythropoiesis involves synthesis of heme and hemoglobin, clearance of the nuclei and other organelles, and remodeling of the plasma membrane, and these processes are exquisitely coordinated by specific regulatory factors including transcriptional factors and signaling molecules. Defects in erythropoiesis can lead to blood disorders such as congenital dyserythropoietic anemias, Diamond–Blackfan anemias, sideroblastic anemias, myelodysplastic syndrome, and porphyria. The molecular mechanisms of erythropoiesis are highly conserved between fish and mammals, and the zebrafish (Danio rerio) has provided a powerful genetic model for studying erythropoiesis. Studies in zebrafish have yielded important insights into RBC development and established a number of models for human blood diseases. Here, we focus on latest discoveries of the molecular processes and mechanisms regulating zebrafish erythropoiesis and summarize newly established zebrafish models of human anemias.
Collapse
|
21
|
Ayagama T, Bose SJ, Capel RA, Priestman DA, Berridge G, Fischer R, Galione A, Platt FM, Kramer H, Burton RA. A modified density gradient proteomic-based method to analyze endolysosomal proteins in cardiac tissue. iScience 2021; 24:102949. [PMID: 34466782 PMCID: PMC8384914 DOI: 10.1016/j.isci.2021.102949] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Revised: 03/04/2021] [Accepted: 08/02/2021] [Indexed: 11/22/2022] Open
Abstract
The importance of lysosomes in cardiac physiology and pathology is well established, and evidence for roles in calcium signaling is emerging. We describe a label-free proteomics method suitable for small cardiac tissue biopsies based on density-separated fractionation, which allows study of endolysosomal (EL) proteins. Density gradient fractions corresponding to tissue lysate; sarcoplasmic reticulum (SR), mitochondria (Mito) (1.3 g/mL); and EL with negligible contamination from SR or Mito (1.04 g/mL) were analyzed using Western blot, enzyme activity assay, and liquid chromatography with tandem mass spectrometry (LC-MS/MS) analysis (adapted discontinuous Percoll and sucrose differential density gradient). Kyoto Encyclopedia of Genes and Genomes, Reactome, Panther, and Gene Ontology pathway analysis showed good coverage of RAB proteins and lysosomal cathepsins (including cardiac-specific cathepsin D) in the purified EL fraction. Significant EL proteins recovered included catalytic activity proteins. We thus present a comprehensive protocol and data set of guinea pig atrial EL organelle proteomics using techniques also applicable for non-cardiac tissue.
Collapse
Affiliation(s)
- Thamali Ayagama
- University of Oxford, Department of Pharmacology, Oxford, OX1 3QT UK
| | - Samuel J. Bose
- University of Oxford, Department of Pharmacology, Oxford, OX1 3QT UK
| | - Rebecca A. Capel
- University of Oxford, Department of Pharmacology, Oxford, OX1 3QT UK
| | | | - Georgina Berridge
- Target Discovery Institute, University of Oxford, Oxford, OX3 7FZ UK
| | - Roman Fischer
- Target Discovery Institute, University of Oxford, Oxford, OX3 7FZ UK
| | - Antony Galione
- University of Oxford, Department of Pharmacology, Oxford, OX1 3QT UK
| | - Frances M. Platt
- University of Oxford, Department of Pharmacology, Oxford, OX1 3QT UK
| | - Holger Kramer
- Biological Mass Spectrometry and Proteomics Facility, MRC London Institute of Medical Sciences, Imperial College London, London, W12 0NN UK
| | | |
Collapse
|
22
|
Unveiling the cryo-EM structure of retromer. Biochem Soc Trans 2021; 48:2261-2272. [PMID: 33125482 DOI: 10.1042/bst20200552] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2020] [Revised: 09/10/2020] [Accepted: 09/14/2020] [Indexed: 12/29/2022]
Abstract
Retromer (VPS26/VPS35/VPS29) is a highly conserved eukaryotic protein complex that localizes to endosomes to sort transmembrane protein cargoes into vesicles and elongated tubules. Retromer mediates retrieval pathways from endosomes to the trans-Golgi network in all eukaryotes and further facilitates recycling pathways to the plasma membrane in metazoans. In cells, retromer engages multiple partners to orchestrate the formation of tubulovesicular structures, including sorting nexin (SNX) proteins, cargo adaptors, GTPases, regulators, and actin remodeling proteins. Retromer-mediated pathways are especially important for sorting cargoes required for neuronal maintenance, which links retromer loss or mutations to multiple human brain diseases and disorders. Structural and biochemical studies have long contributed to the understanding of retromer biology, but recent advances in cryo-electron microscopy and cryo-electron tomography have further uncovered exciting new snapshots of reconstituted retromer structures. These new structures reveal retromer assembles into an arch-shaped scaffold and suggest the scaffold may be flexible and adaptable in cells. Interactions with cargo adaptors, particularly SNXs, likely orient the scaffold with respect to phosphatidylinositol-3-phosphate (PtdIns3P)-enriched membranes. Pharmacological small molecule chaperones have further been shown to stabilize retromer in cultured cell and mouse models, but mechanisms by which these molecules bind remain unknown. This review will emphasize recent structural and biophysical advances in understanding retromer structure as the field moves towards a molecular view of retromer assembly and regulation on membranes.
Collapse
|
23
|
Rondelli CM, Perfetto M, Danoff A, Bergonia H, Gillis S, O'Neill L, Jackson L, Nicolas G, Puy H, West R, Phillips JD, Yien YY. The ubiquitous mitochondrial protein unfoldase CLPX regulates erythroid heme synthesis by control of iron utilization and heme synthesis enzyme activation and turnover. J Biol Chem 2021; 297:100972. [PMID: 34280433 PMCID: PMC8361296 DOI: 10.1016/j.jbc.2021.100972] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Revised: 07/13/2021] [Accepted: 07/15/2021] [Indexed: 11/19/2022] Open
Abstract
Heme plays a critical role in catalyzing life-essential redox reactions in all cells, and its synthesis must be tightly balanced with cellular requirements. Heme synthesis in eukaryotes is tightly regulated by the mitochondrial AAA+ unfoldase CLPX (caseinolytic mitochondrial matrix peptidase chaperone subunit X), which promotes heme synthesis by activation of δ-aminolevulinate synthase (ALAS/Hem1) in yeast and regulates turnover of ALAS1 in human cells. However, the specific mechanisms by which CLPX regulates heme synthesis are unclear. In this study, we interrogated the mechanisms by which CLPX regulates heme synthesis in erythroid cells. Quantitation of enzyme activity and protein degradation showed that ALAS2 stability and activity were both increased in the absence of CLPX, suggesting that CLPX primarily regulates ALAS2 by control of its turnover, rather than its activation. However, we also showed that CLPX is required for PPOX (protoporphyrinogen IX oxidase) activity and maintenance of FECH (ferrochelatase) levels, which are the terminal enzymes in heme synthesis, likely accounting for the heme deficiency and porphyrin accumulation observed in Clpx−/− cells. Lastly, CLPX is required for iron utilization for hemoglobin synthesis during erythroid differentiation. Collectively, our data show that the role of CLPX in yeast ALAS/Hem1 activation is not conserved in vertebrates as vertebrates rely on CLPX to regulate ALAS turnover as well as PPOX and FECH activity. Our studies reveal that CLPX mutations may cause anemia and porphyria via dysregulation of ALAS, FECH, and PPOX activities, as well as of iron metabolism.
Collapse
Affiliation(s)
- Catherine M Rondelli
- Department of Biological Sciences, University of Delaware, Newark, Delaware, USA
| | - Mark Perfetto
- Department of Biological Sciences, University of Delaware, Newark, Delaware, USA; Pittsburgh Heart, Lung and Blood Vascular Medicine Institute and Department of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Aidan Danoff
- Department of Biological Sciences, University of Delaware, Newark, Delaware, USA
| | - Hector Bergonia
- Division of Hematology, University of Utah School of Medicine, Salt Lake City, Utah, USA
| | - Samantha Gillis
- Department of Biological Sciences, University of Delaware, Newark, Delaware, USA
| | - Leah O'Neill
- Department of Biological Sciences, University of Delaware, Newark, Delaware, USA
| | - Laurie Jackson
- Division of Hematology, University of Utah School of Medicine, Salt Lake City, Utah, USA
| | - Gael Nicolas
- Centre de Recherche sur l'inflammation, Université Paris Diderot, Site Bichat, Sorbonne Paris Cité, Paris, France
| | - Herve Puy
- Centre de Recherche sur l'inflammation, Université Paris Diderot, Site Bichat, Sorbonne Paris Cité, Paris, France; Centre Français des Porphyries, Hôpital Louis Mourier, APHP, Colombes, France
| | - Richard West
- Delaware Biotechnology Institute, University of Delaware, Newark, Delaware, USA
| | - John D Phillips
- Division of Hematology, University of Utah School of Medicine, Salt Lake City, Utah, USA
| | - Yvette Y Yien
- Department of Biological Sciences, University of Delaware, Newark, Delaware, USA; Pittsburgh Heart, Lung and Blood Vascular Medicine Institute and Department of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, USA.
| |
Collapse
|
24
|
Lu J, Xu S, Huo Y, Sun D, Hu Y, Wang J, Zhang X, Wang P, Li Z, Liang M, Wu Z, Liu P. Sorting nexin 3 induces heart failure via promoting retromer-dependent nuclear trafficking of STAT3. Cell Death Differ 2021; 28:2871-2887. [PMID: 33947971 DOI: 10.1038/s41418-021-00789-w] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2020] [Revised: 04/08/2021] [Accepted: 04/15/2021] [Indexed: 12/18/2022] Open
Abstract
Sorting nexins (SNXs), the retromer-associated cargo binding proteins, have emerged as critical regulators of the trafficking of proteins involved in the pathogenesis of diverse diseases. However, studies of SNXs in the development of cardiovascular diseases, especially cardiac hypertrophy and heart failure, are lacking. Here, we ask whether SNX3, the simplest structured isoform in the SNXs family, may act as a key inducer of myocardial injury. An increased level of SNX3 was observed in failing hearts from human patients and mice. Cardiac-specific Snx3 knockout (Snx3-cKO) mice and Snx3 transgenic (Snx3-cTg) mice were generated to evaluate the role of Snx3 in myocardial hypertrophy, fibrosis, and heart function by morphology, echocardiography, histological staining, and hypertrophic biomarkers. We report that Snx3-cKO in mice significantly protected against isoproterenol (ISO)-induced cardiac hypertrophy at 12 weeks. Conversely, Snx3-cTg mice were more susceptible to ISO-induced cardiac hypertrophy at 12 weeks and showed aggravated cardiac injury even heart failure at 24 weeks. Immunoprecipitation-based mass spectrometry, immunofluorescent staining, co-immunoprecipitation, localized surface plasmon resonance, and proximity ligation assay were performed to examine the direct interaction of SNX3-retromer with signal transducer and activator of transcription 3 (STAT3). We discovered that STAT3 was a new interacting partner of SNX3-retromer, and SNX3-retromer served as an essential platform for assembling gp130/JAK2/STAT3 complexes and subsequent phosphorylation of STAT3 by direct combination at EE. SNX3-retromer and STAT3 complexes were transiently imported into the nucleus after hypertrophic stimuli. The pharmacological inhibition or knockdown of STAT3 reversed SNX3 overexpression-induced myocardial injury. STAT3 overexpression blunts the beneficial function of SNX3 knockdown on hypertrophic cardiomyocytes. We show that SNX3-retromer promoted importin α3-mediated STAT3 nuclear trafficking and ultimately leading to cardiac injury. Taken together, our study reveals that SNX3 plays a key role in cardiac function and implicates SNX3 as a potential therapeutic target for cardiac hypertrophy and heart failure.
Collapse
Affiliation(s)
- Jing Lu
- School of Pharmaceutical Sciences, National and Local United Engineering Lab of Druggability and New Drugs Evaluation, Sun Yat-sen University, Guangzhou, P. R. China
| | - Suowen Xu
- Aab Cardiovascular Research Institute, University of Rochester School of Medicine and Dentistry, Rochester, NY, USA.,Department of Endocrinology, the First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, P. R. China
| | - Yuqing Huo
- Department of Cellular Biology and Anatomy, Medical College of Georgia, Vascular Biology Center, Augusta University, Augusta, GA, USA
| | - Duanping Sun
- Center for Drug Research and Development, Guangdong Pharmaceutical University, Guangzhou, P.R. China
| | - Yuehuai Hu
- School of Pharmaceutical Sciences, National and Local United Engineering Lab of Druggability and New Drugs Evaluation, Sun Yat-sen University, Guangzhou, P. R. China
| | - Junjian Wang
- School of Pharmaceutical Sciences, National and Local United Engineering Lab of Druggability and New Drugs Evaluation, Sun Yat-sen University, Guangzhou, P. R. China
| | - Xiaolei Zhang
- School of Pharmaceutical Sciences, National and Local United Engineering Lab of Druggability and New Drugs Evaluation, Sun Yat-sen University, Guangzhou, P. R. China
| | - Panxia Wang
- School of Pharmaceutical Sciences, National and Local United Engineering Lab of Druggability and New Drugs Evaluation, Sun Yat-sen University, Guangzhou, P. R. China
| | - Zhuoming Li
- School of Pharmaceutical Sciences, National and Local United Engineering Lab of Druggability and New Drugs Evaluation, Sun Yat-sen University, Guangzhou, P. R. China
| | - Mengya Liang
- Department of Cardiac Surgery, First Affiliated Hospital, Sun Yat-sen University, Guangzhou, P.R. China
| | - Zhongkai Wu
- Department of Cardiac Surgery, First Affiliated Hospital, Sun Yat-sen University, Guangzhou, P.R. China.
| | - Peiqing Liu
- School of Pharmaceutical Sciences, National and Local United Engineering Lab of Druggability and New Drugs Evaluation, Sun Yat-sen University, Guangzhou, P. R. China.
| |
Collapse
|
25
|
Canesin G, Janovicova L, Wegiel B. Measurement of labile and protein-bound heme in fixed prostate cancer cells and in cellular fractions. STAR Protoc 2021; 2:100491. [PMID: 33997811 PMCID: PMC8091920 DOI: 10.1016/j.xpro.2021.100491] [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] [Indexed: 02/06/2023] Open
Abstract
Labile heme is present in the cells at very low concentrations, either unbound or loosely bound to molecules, and accessible for signaling as alarmin. Our recent work suggests that extracellular heme can be taken up and detected in the nuclei of cancer cells. Here, we describe the detailed protocol for detection of labile and total heme in prostate cancer cells and its measurement in subcellular compartments in vitro. The protocol can be adapted to be used for other cell types. For complete details on the use and execution of this protocol, please refer to Canesin et al. (2020). Preparation of heme and treatment of cells with heme Detection of labile and total heme in prostate cancer cells Measurement of heme in subcellular compartments in prostate cancer cells Detection of heme in fixed cells
Collapse
Affiliation(s)
- Giacomo Canesin
- Department of Surgery, Division of Surgical Oncology, Cancer Research Institute, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02214, USA
| | - Lubica Janovicova
- Department of Surgery, Division of Surgical Oncology, Cancer Research Institute, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02214, USA
| | - Barbara Wegiel
- Department of Surgery, Division of Surgical Oncology, Cancer Research Institute, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02214, USA
| |
Collapse
|
26
|
Wang X, Wu H, Zhao L, Liu Z, Qi M, Jin Y, Liu W. FLCN regulates transferrin receptor 1 transport and iron homeostasis. J Biol Chem 2021; 296:100426. [PMID: 33609526 PMCID: PMC7995610 DOI: 10.1016/j.jbc.2021.100426] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Revised: 01/19/2021] [Accepted: 02/12/2021] [Indexed: 11/30/2022] Open
Abstract
Birt–Hogg–Dubé (BHD) syndrome is a multiorgan disorder caused by inactivation of the folliculin (FLCN) protein. Previously, we identified FLCN as a binding protein of Rab11A, a key regulator of the endocytic recycling pathway. This finding implies that the abnormal localization of specific proteins whose transport requires the FLCN-Rab11A complex may contribute to BHD. Here, we used human kidney-derived HEK293 cells as a model, and we report that FLCN promotes the binding of Rab11A with transferrin receptor 1 (TfR1), which is required for iron uptake through continuous trafficking between the cell surface and the cytoplasm. Loss of FLCN attenuated the Rab11A–TfR1 interaction, resulting in delayed recycling transport of TfR1. This delay caused an iron deficiency condition that induced hypoxia-inducible factor (HIF) activity, which was reversed by iron supplementation. In a Drosophila model of BHD syndrome, we further demonstrated that the phenotype of BHD mutant larvae was substantially rescued by an iron-rich diet. These findings reveal a conserved function of FLCN in iron metabolism and may help to elucidate the mechanisms driving BHD syndrome.
Collapse
Affiliation(s)
- Xiaojuan Wang
- College of Veterinary Medicine, Northwest A&F University, Yangling, Shanxi, China
| | - Hanjie Wu
- College of Veterinary Medicine, Northwest A&F University, Yangling, Shanxi, China
| | - Lingling Zhao
- College of Veterinary Medicine, Northwest A&F University, Yangling, Shanxi, China
| | - Zeyao Liu
- College of Veterinary Medicine, Northwest A&F University, Yangling, Shanxi, China
| | - Maozhen Qi
- College of Veterinary Medicine, Northwest A&F University, Yangling, Shanxi, China
| | - Yaping Jin
- College of Veterinary Medicine, Northwest A&F University, Yangling, Shanxi, China.
| | - Wei Liu
- College of Veterinary Medicine, Northwest A&F University, Yangling, Shanxi, China.
| |
Collapse
|
27
|
Hanley SE, Cooper KF. Sorting Nexins in Protein Homeostasis. Cells 2020; 10:cells10010017. [PMID: 33374212 PMCID: PMC7823608 DOI: 10.3390/cells10010017] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2020] [Revised: 12/15/2020] [Accepted: 12/18/2020] [Indexed: 12/11/2022] Open
Abstract
Protein homeostasis is maintained by removing misfolded, damaged, or excess proteins and damaged organelles from the cell by three major pathways; the ubiquitin-proteasome system, the autophagy-lysosomal pathway, and the endo-lysosomal pathway. The requirement for ubiquitin provides a link between all three pathways. Sorting nexins are a highly conserved and diverse family of membrane-associated proteins that not only traffic proteins throughout the cells but also provide a second common thread between protein homeostasis pathways. In this review, we will discuss the connections between sorting nexins, ubiquitin, and the interconnected roles they play in maintaining protein quality control mechanisms. Underlying their importance, genetic defects in sorting nexins are linked with a variety of human diseases including neurodegenerative, cardiovascular diseases, viral infections, and cancer. This serves to emphasize the critical roles sorting nexins play in many aspects of cellular function.
Collapse
|
28
|
Gammella E, Lomoriello IS, Conte A, Freddi S, Alberghini A, Poli M, Sigismund S, Cairo G, Recalcati S. Unconventional endocytosis and trafficking of transferrin receptor induced by iron. Mol Biol Cell 2020; 32:98-108. [PMID: 33236955 PMCID: PMC8120689 DOI: 10.1091/mbc.e20-02-0129] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
The posttranslational regulation of transferrin receptor (TfR1) is largely unknown. We investigated whether iron availability affects TfR1 endocytic cycle and protein stability in HepG2 hepatoma cells exposed to ferric ammonium citrate (FAC). NH4Cl and bafilomycin A1, but not the proteasomal inhibitor MG132, prevented the FAC-mediated decrease in TfR1 protein levels, thus indicating lysosomal involvement. Knockdown experiments showed that TfR1 lysosomal degradation is independent of 1) endocytosis mediated by the clathrin adaptor AP2; 2) Tf, which was suggested to facilitate TfR1 internalization; 3) H-ferritin; and 4) MARCH8, previously implicated in TfR1 degradation. Notably, FAC decreased the number of TfR1 molecules at the cell surface and increased the Tf endocytic rate. Colocalization experiments confirmed that, upon FAC treatment, TfR1 was endocytosed in an AP2- and Tf-independent pathway and trafficked to the lysosome for degradation. This unconventional endocytic regulatory mechanism aimed at reducing surface TfR1 may represent an additional posttranslational control to prevent iron overload. Our results show that iron is a key regulator of the trafficking of TfR1, which has been widely used to study endocytosis, often not considering its function in iron homeostasis.
Collapse
Affiliation(s)
- Elena Gammella
- Department of Biomedical Sciences for Health, University of Milan, 20133 Milan, Italy
| | | | - Alexia Conte
- IEO, Istituto Europeo di Oncologia IRCCS, 20141 Milan, Italy
| | - Stefano Freddi
- IEO, Istituto Europeo di Oncologia IRCCS, 20141 Milan, Italy
| | - Alessandra Alberghini
- Department of Biomedical Sciences for Health, University of Milan, 20133 Milan, Italy
| | - Maura Poli
- Department of Molecular and Translational Medicine, University of Brescia, 25123 Brescia, Italy
| | - Sara Sigismund
- IEO, Istituto Europeo di Oncologia IRCCS, 20141 Milan, Italy.,Department of Oncology and Hematology-Oncology, Università degli Studi di Milano, 20122, Milan, Italy
| | - Gaetano Cairo
- Department of Biomedical Sciences for Health, University of Milan, 20133 Milan, Italy
| | - Stefania Recalcati
- Department of Biomedical Sciences for Health, University of Milan, 20133 Milan, Italy
| |
Collapse
|
29
|
Brown HM, Murray SA, Northrup H, Au KS, Niswander LA. Snx3 is important for mammalian neural tube closure via its role in canonical and non-canonical WNT signaling. Development 2020; 147:147/22/dev192518. [PMID: 33214242 DOI: 10.1242/dev.192518] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2020] [Accepted: 10/09/2020] [Indexed: 12/26/2022]
Abstract
Disruptions in neural tube (NT) closure result in neural tube defects (NTDs). To understand the molecular processes required for mammalian NT closure, we investigated the role of Snx3, a sorting nexin gene. Snx3-/- mutant mouse embryos display a fully-penetrant cranial NTD. In vivo, we observed decreased canonical WNT target gene expression in the cranial neural epithelium of the Snx3-/- embryos and a defect in convergent extension of the neural epithelium. Snx3-/- cells show decreased WNT secretion, and live cell imaging reveals aberrant recycling of the WNT ligand-binding protein WLS and mis-trafficking to the lysosome for degradation. The importance of SNX3 in WNT signaling regulation is demonstrated by rescue of NT closure in Snx3-/- embryos with a WNT agonist. The potential for SNX3 to function in human neurulation is revealed by a point mutation identified in an NTD-affected individual that results in functionally impaired SNX3 that does not colocalize with WLS and the degradation of WLS in the lysosome. These data indicate that Snx3 is crucial for NT closure via its role in recycling WLS in order to control levels of WNT signaling.
Collapse
Affiliation(s)
- Heather Mary Brown
- Cell Biology, Stem Cells, and Developmental Biology Graduate Program, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA.,Department of Molecular, Cellular, and Developmental Biology, University of Colorado Boulder, Boulder, CO 80309, USA
| | | | - Hope Northrup
- Department of Pediatrics, McGovern Medical School, University of Texas Health Science Center at Houston, Houston, TX 77030, USA
| | - Kit Sing Au
- Department of Pediatrics, McGovern Medical School, University of Texas Health Science Center at Houston, Houston, TX 77030, USA
| | - Lee A Niswander
- Department of Molecular, Cellular, and Developmental Biology, University of Colorado Boulder, Boulder, CO 80309, USA
| |
Collapse
|
30
|
Crispin A, Guo C, Chen C, Campagna DR, Schmidt PJ, Lichtenstein D, Cao C, Sendamarai AK, Hildick-Smith GJ, Huston NC, Boudreaux J, Bottomley SS, Heeney MM, Paw BH, Fleming MD, Ducamp S. Mutations in the iron-sulfur cluster biogenesis protein HSCB cause congenital sideroblastic anemia. J Clin Invest 2020; 130:5245-5256. [PMID: 32634119 PMCID: PMC7524500 DOI: 10.1172/jci135479] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2019] [Accepted: 06/24/2020] [Indexed: 01/15/2023] Open
Abstract
The congenital sideroblastic anemias (CSAs) can be caused by primary defects in mitochondrial iron-sulfur (Fe-S) cluster biogenesis. HSCB (heat shock cognate B), which encodes a mitochondrial cochaperone, also known as HSC20 (heat shock cognate protein 20), is the partner of mitochondrial heat shock protein A9 (HSPA9). Together with glutaredoxin 5 (GLRX5), HSCB and HSPA9 facilitate the transfer of nascent 2-iron, 2-sulfur clusters to recipient mitochondrial proteins. Mutations in both HSPA9 and GLRX5 have previously been associated with CSA. Therefore, we hypothesized that mutations in HSCB could also cause CSA. We screened patients with genetically undefined CSA and identified a frameshift mutation and a rare promoter variant in HSCB in a female patient with non-syndromic CSA. We found that HSCB expression was decreased in patient-derived fibroblasts and K562 erythroleukemia cells engineered to have the patient-specific promoter variant. Furthermore, gene knockdown and deletion experiments performed in K562 cells, zebrafish, and mice demonstrate that loss of HSCB results in impaired Fe-S cluster biogenesis, a defect in RBC hemoglobinization, and the development of siderocytes and more broadly perturbs hematopoiesis in vivo. These results further affirm the involvement of Fe-S cluster biogenesis in erythropoiesis and hematopoiesis and define HSCB as a CSA gene.
Collapse
Affiliation(s)
- Andrew Crispin
- Department of Pathology, Boston Children’s Hospital, Boston, Massachusetts, USA
| | - Chaoshe Guo
- Department of Pathology, Boston Children’s Hospital, Boston, Massachusetts, USA
| | - Caiyong Chen
- Division of Hematology, Brigham and Women’s Hospital, Boston, Massachusetts, USA
| | - Dean R. Campagna
- Department of Pathology, Boston Children’s Hospital, Boston, Massachusetts, USA
| | - Paul J. Schmidt
- Department of Pathology, Boston Children’s Hospital, Boston, Massachusetts, USA
| | - Daniel Lichtenstein
- Department of Pathology, Boston Children’s Hospital, Boston, Massachusetts, USA
| | - Chang Cao
- Department of Pathology, Boston Children’s Hospital, Boston, Massachusetts, USA
| | - Anoop K. Sendamarai
- Department of Pathology, Boston Children’s Hospital, Boston, Massachusetts, USA
| | | | - Nicholas C. Huston
- Division of Hematology, Brigham and Women’s Hospital, Boston, Massachusetts, USA
| | - Jeanne Boudreaux
- Aflac Cancer and Blood Disorders Center, Children’s Healthcare of Atlanta and Department of Pediatrics, Emory University, Atlanta, Georgia, USA
| | - Sylvia S. Bottomley
- Department of Medicine, University of Oklahoma College of Medicine, Oklahoma City, Oklahoma, USA
| | - Matthew M. Heeney
- Dana-Farber/Boston Children’s Cancer and Blood Disorders Center, Boston, Massachusetts, USA
| | - Barry H. Paw
- Division of Hematology, Brigham and Women’s Hospital, Boston, Massachusetts, USA
| | - Mark D. Fleming
- Department of Pathology, Boston Children’s Hospital, Boston, Massachusetts, USA
| | - Sarah Ducamp
- Department of Pathology, Boston Children’s Hospital, Boston, Massachusetts, USA
| |
Collapse
|
31
|
Sobh A, Loguinov A, Zhou J, Jenkitkasemwong S, Zeidan R, El Ahmadie N, Tagmount A, Knutson M, Fraenkel PG, Vulpe CD. Genetic screens reveal CCDC115 as a modulator of erythroid iron and heme trafficking. Am J Hematol 2020; 95:1085-1098. [PMID: 32510613 DOI: 10.1002/ajh.25899] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2020] [Revised: 05/27/2020] [Accepted: 05/31/2020] [Indexed: 12/26/2022]
Abstract
Transferrin-bound iron (TBI), the physiological circulating iron form, is acquired by cells through the transferrin receptor (TfR1) by endocytosis. In erythroid cells, most of the acquired iron is incorporated into heme in the mitochondria. Cellular trafficking of heme is indispensable for erythropoiesis and many other essential biological processes. Comprehensive elucidation of molecular pathways governing and regulating cellular iron acquisition and heme trafficking is required to better understand physiological and pathological processes affecting erythropoiesis. Here, we report the first genome-wide clustered regularly interspaced short palindromic repeats (CRISPR) screens in human erythroid cells to identify determinants of iron and heme uptake, as well as heme-mediated erythroid differentiation. We identified several candidate modulators of TBI acquisition including TfR1, indicating that our approach effectively revealed players mechanistically relevant to the process. Interestingly, components of the endocytic pathway were also revealed as potential determinants of transferrin acquisition. We deciphered a role for the vacuolar-type H+ - ATPase (V- ATPase) assembly factor coiled-coil domain containing 115 (CCDC115) in TBI uptake and validated this role in CCDC115 deficient K562 cells. Our screen in hemin-treated cells revealed perturbations leading to cellular adaptation to heme, including those corresponding to trafficking mechanisms and transcription factors potentiating erythroid differentiation. Pathway analysis indicated that endocytosis and vesicle acidification are key processes for heme trafficking in erythroid precursors. Furthermore, we provided evidence that CCDC115, which we identified as required for TBI uptake, is also involved in cellular heme distribution. This work demonstrates a previously unappreciated common intersection in trafficking of transferrin iron and heme in the endocytic pathway of erythroid cells.
Collapse
Affiliation(s)
- Amin Sobh
- Department of Nutritional Sciences & Toxicology, Comparative Biochemistry Program University of California Berkeley Berkeley California
- Department of Physiological Sceinces University of Florida Gainesville Florida
| | - Alex Loguinov
- Department of Physiological Sceinces University of Florida Gainesville Florida
| | - Jie Zhou
- Department of Physiological Sceinces University of Florida Gainesville Florida
- Department of Food Science and Human Nutrition University of Florida Gainesville Florida
| | - Supak Jenkitkasemwong
- Department of Food Science and Human Nutrition University of Florida Gainesville Florida
| | - Rola Zeidan
- Department of Physiological Sceinces University of Florida Gainesville Florida
| | - Nader El Ahmadie
- Department of Physiological Sceinces University of Florida Gainesville Florida
| | | | - Mitchell Knutson
- Department of Food Science and Human Nutrition University of Florida Gainesville Florida
| | - Paula G. Fraenkel
- Division of Hematology/Oncology and Cancer Research Institute Beth Israel Deaconess Medical Center Boston Massachusetts
- Department of Medicine Harvard Medical School Boston Massachusetts
- Oncology Research and Development, Sanofi Cambridge Massachusetts
| | | |
Collapse
|
32
|
Deatherage CL, Nikolaus J, Karatekin E, Burd CG. Retromer forms low order oligomers on supported lipid bilayers. J Biol Chem 2020; 295:12305-12316. [PMID: 32651229 PMCID: PMC7443500 DOI: 10.1074/jbc.ra120.013672] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2020] [Revised: 07/03/2020] [Indexed: 12/18/2022] Open
Abstract
Retromer orchestrates the selection and export of integral membrane proteins from the endosome via retrograde and plasma membrane recycling pathways. Long-standing hypotheses regarding the retromer sorting mechanism posit that oligomeric interactions between retromer and associated accessory factors on the endosome membrane drives clustering of retromer-bound integral membrane cargo prior to its packaging into a nascent transport carrier. To test this idea, we examined interactions between components of the sorting nexin 3 (SNX3)-retromer sorting pathway using quantitative single particle fluorescence microscopy in a reconstituted system. This system includes a supported lipid bilayer, fluorescently labeled retromer, SNX3, and two model cargo proteins, RAB7, and retromer-binding segments of the WASHC2C subunit of the WASH complex. We found that the distribution of membrane-associated retromer is predominantly comprised of monomer (∼18%), dimer (∼35%), trimer (∼24%), and tetramer (∼13%). Unexpectedly, neither the presence of membrane-associated cargo nor accessory factors substantially affected this distribution. The results indicate that retromer has an intrinsic propensity to form low order oligomers on a supported lipid bilayer and that neither membrane association nor accessory factors potentiate oligomerization. The results support a model whereby SNX3-retromer is a minimally concentrative coat protein complex adapted to bulk membrane trafficking from the endosomal system.
Collapse
Affiliation(s)
| | - Joerg Nikolaus
- Department of Cellular and Molecular Physiology, Yale School of Medicine, New Haven, Connecticut, USA
| | - Erdem Karatekin
- Department of Cellular and Molecular Physiology, Yale School of Medicine, New Haven, Connecticut, USA; Nanobiology Institute, Yale University, West Haven, Connecticut, USA; Department of Molecular Biophysics and Biochemistry, Yale School of Medicine, New Haven, Connecticut, USA; Saints-Pères Paris Institute for the Neurosciences (SPPIN), CNRS, Université de Paris, Paris, France.
| | - Christopher G Burd
- Department of Cell Biology, Yale School of Medicine, New Haven, Connecticut, USA.
| |
Collapse
|
33
|
Over 60 Years of Experimental Hematology (without a License). Exp Hematol 2020; 89:1-12. [PMID: 32798645 DOI: 10.1016/j.exphem.2020.08.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2020] [Revised: 08/06/2020] [Accepted: 08/07/2020] [Indexed: 11/21/2022]
Abstract
I am deeply honored to receive the International Society for Experimental Hematology (ISEH) 2020 Donald Metcalf Lecture Award. Although I am not a physician and have had no formal training in hematology, I have had the privilege of working with some of the top hematologists in the world, beginning in 1970 when Dr. David Nathan was a sabbatical visitor in my laboratory and introduced me to hematological diseases. And I take this award to be given not just to me but to an exceptional group of MD and PhD trainees and visitors in my laboratory who have cloned and characterized many proteins and RNAs important for red cell development and function. Many of these projects involved taking exceptionally large risks in developing and employing novel experimental technologies. Unsurprisingly, all of these trainees have gone on to become leaders in hematology and, more broadly, in molecular cell biology and molecular medicine. To illustrate some of the challenges we have faced and the technologies we had to develop, I have chosen several of our multiyear projects to describe in some detail: elucidating the regulation of translation of α- and β-globin mRNAs and the defect in beta thalassemia in the 1970s; cloning the Epo receptor and several red cell membrane proteins in the 1980s and 1990s; and more recently, determining the function of many microRNAs and long noncoding RNAs in red cell development. I summarize how we are currently utilizing single-cell transcriptomics (scRNAseq) to understand how dividing transit-amplifying burst-forming unit erythroid progenitors balance the need for more progenitor cells with the need for terminally differentiated erythroid cells, and to identify drugs potentially useful in treating Epo-resistant anemias such as Diamond Blackfan anemia. I hope that the lessons I learned in managing these diverse fellows and projects, initially without having grants to support them, will be helpful to others who would like to undertake ambitious and important lines of research in hematology.
Collapse
|
34
|
Macías-Calvio V, Fuentealba LM, Marzolo MP. An update on cellular and molecular determinants of Parkinson's disease with emphasis on the role of the retromer complex. J Neurosci Res 2020; 99:163-179. [PMID: 32633426 DOI: 10.1002/jnr.24675] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2019] [Revised: 05/25/2020] [Accepted: 05/26/2020] [Indexed: 12/15/2022]
Abstract
Parkinson's disease (PD) is a highly prevalent neurodegenerative condition. The disease involves the progressive degeneration of dopaminergic neurons located in the substantia nigra pars compacta. Among late-onset, familial forms of Parkinson are cases with mutations in the PARK17 locus encoding the vacuolar protein sorting 35 (Vps35), a subunit of the retromer complex. The retromer complex is composed of a heterotrimeric protein core (Vps26-Vps35-Vps29). The best-known role of retromer is the retrieval of cargoes from endosomes to the Golgi complex or the plasma membrane. However, recent literature indicates that retromer performs roles associated with lysosomal and mitochondrial functions and degradative pathways such as autophagy. A common point mutation affecting the retromer subunit Vps35 is D620N, which has been linked to the alterations in the aforementioned cellular processes as well as with neurodegeneration. Here, we review the main aspects of the malfunction of the retromer complex and its implications for PD pathology. Besides, we highlight several controversies still awaiting clarification.
Collapse
Affiliation(s)
- Vania Macías-Calvio
- Laboratorio de Tráfico Intracelular y Señalización, Departamento de Biología Celular y Molecular, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Luz-María Fuentealba
- Laboratorio de Tráfico Intracelular y Señalización, Departamento de Biología Celular y Molecular, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - María-Paz Marzolo
- Laboratorio de Tráfico Intracelular y Señalización, Departamento de Biología Celular y Molecular, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
| |
Collapse
|
35
|
Regulation of Iron Homeostasis and Related Diseases. Mediators Inflamm 2020; 2020:6062094. [PMID: 32454791 PMCID: PMC7212278 DOI: 10.1155/2020/6062094] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2020] [Accepted: 03/23/2020] [Indexed: 12/18/2022] Open
Abstract
The liver is the organ for iron storage and regulation; it senses circulating iron concentrations in the body through the BMP-SMAD pathway and regulates the iron intake from food and erythrocyte recovery into the bloodstream by secreting hepcidin. Under iron deficiency, hypoxia, and hemorrhage, the liver reduces the expression of hepcidin to ensure the erythropoiesis but increases the excretion of hepcidin during infection and inflammation to reduce the usage of iron by pathogens. Excessive iron causes system iron overload; it accumulates in never system and damages neurocyte leading to neurodegenerative diseases such as Parkinson's syndrome. When some gene mutations affect the perception of iron and iron regulation ability in the liver, then they decrease the expression of hepcidin, causing hereditary diseases such as hereditary hemochromatosis. This review summarizes the source and utilization of iron in the body, the liver regulates systemic iron homeostasis by sensing the circulating iron concentration, and the expression of hepcidin regulated by various signaling pathways, thereby understanding the pathogenesis of iron-related diseases.
Collapse
|
36
|
Wdr26 regulates nuclear condensation in developing erythroblasts. Blood 2020; 135:208-219. [PMID: 31945154 DOI: 10.1182/blood.2019002165] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2019] [Accepted: 11/04/2019] [Indexed: 02/07/2023] Open
Abstract
Mammalian red blood cells lack nuclei. The molecular mechanisms underlying erythroblast nuclear condensation and enucleation, however, remain poorly understood. Here we show that Wdr26, a gene upregulated during terminal erythropoiesis, plays an essential role in regulating nuclear condensation in differentiating erythroblasts. Loss of Wdr26 induces anemia in zebrafish and enucleation defects in mouse erythroblasts because of impaired erythroblast nuclear condensation. As part of the glucose-induced degradation-deficient ubiquitin ligase complex, Wdr26 regulates the ubiquitination and degradation of nuclear proteins, including lamin B. Failure of lamin B degradation blocks nuclear opening formation leading to impaired clearance of nuclear proteins and delayed nuclear condensation. Collectively, our study reveals an unprecedented role of an E3 ubiquitin ligase in regulating nuclear condensation and enucleation during terminal erythropoiesis. Our results provide mechanistic insights into nuclear protein homeostasis and vertebrate red blood cell development.
Collapse
|
37
|
Identification of Host Trafficking Genes Required for HIV-1 Virological Synapse Formation in Dendritic Cells. J Virol 2020; 94:JVI.01597-19. [PMID: 32075937 PMCID: PMC7163131 DOI: 10.1128/jvi.01597-19] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2019] [Accepted: 02/04/2020] [Indexed: 01/15/2023] Open
Abstract
The lentivirus human immunodeficiency virus (HIV) targets and destroys CD4+ T cells, leaving the host vulnerable to life-threatening opportunistic infections associated with AIDS. Dendritic cells (DCs) form a virological synapse (VS) with CD4+ T cells, enabling the efficient transfer of virus between the two cells. We have identified cellular factors that are critical in the induction of the VS. We show that ADP-ribosylation factor 1 (ARF1), bridging integrator 1 (BIN1), and Rab GTPases RAB7L1 and RAB8A are important regulators of HIV-1 trafficking to the VS and therefore the infection of CD4+ T cells. We found these cellular factors were essential for endosomal protein trafficking and formation of the VS and that depletion of target proteins prevented virus trafficking to the plasma membrane by retaining virus in intracellular vesicles. Identification of key regulators in HIV-1 trans-infection between DC and CD4+ T cells has the potential for the development of targeted therapy to reduce trans-infection of HIV-1 in vivo. Dendritic cells (DCs) are one of the earliest targets of HIV-1 infection acting as a “Trojan horse,” concealing the virus from the innate immune system and delivering it to T cells via virological synapses (VS). To explicate how the virus is trafficked through the cell to the VS and evades degradation, a high-throughput small interfering RNA screen targeting membrane trafficking proteins was performed in monocyte-derived DCs. We identified several proteins including BIN-1 and RAB7L1 that share common roles in transport from endosomal compartments. Depletion of target proteins resulted in an accumulation of virus in intracellular compartments and significantly reduced viral trans-infection via the VS. By targeting endocytic trafficking and retromer recycling to the plasma membrane, we were able to reduce the virus’s ability to accumulate at budding microdomains and the VS. Thus, we identify key genes involved in a pathway within DCs that is exploited by HIV-1 to traffic to the VS. IMPORTANCE The lentivirus human immunodeficiency virus (HIV) targets and destroys CD4+ T cells, leaving the host vulnerable to life-threatening opportunistic infections associated with AIDS. Dendritic cells (DCs) form a virological synapse (VS) with CD4+ T cells, enabling the efficient transfer of virus between the two cells. We have identified cellular factors that are critical in the induction of the VS. We show that ADP-ribosylation factor 1 (ARF1), bridging integrator 1 (BIN1), and Rab GTPases RAB7L1 and RAB8A are important regulators of HIV-1 trafficking to the VS and therefore the infection of CD4+ T cells. We found these cellular factors were essential for endosomal protein trafficking and formation of the VS and that depletion of target proteins prevented virus trafficking to the plasma membrane by retaining virus in intracellular vesicles. Identification of key regulators in HIV-1 trans-infection between DC and CD4+ T cells has the potential for the development of targeted therapy to reduce trans-infection of HIV-1 in vivo.
Collapse
|
38
|
Neonatal lethality and recycling defect of transferrin receptor in mice with Syntaxin12/13 disruption. Protein Cell 2019; 10:67-71. [PMID: 29511932 PMCID: PMC6321817 DOI: 10.1007/s13238-018-0519-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
|
39
|
Wright Muelas M, Mughal F, O'Hagan S, Day PJ, Kell DB. The role and robustness of the Gini coefficient as an unbiased tool for the selection of Gini genes for normalising expression profiling data. Sci Rep 2019; 9:17960. [PMID: 31784565 PMCID: PMC6884504 DOI: 10.1038/s41598-019-54288-7] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2019] [Accepted: 11/08/2019] [Indexed: 12/13/2022] Open
Abstract
We recently introduced the Gini coefficient (GC) for assessing the expression variation of a particular gene in a dataset, as a means of selecting improved reference genes over the cohort ('housekeeping genes') typically used for normalisation in expression profiling studies. Those genes (transcripts) that we determined to be useable as reference genes differed greatly from previous suggestions based on hypothesis-driven approaches. A limitation of this initial study is that a single (albeit large) dataset was employed for both tissues and cell lines. We here extend this analysis to encompass seven other large datasets. Although their absolute values differ a little, the Gini values and median expression levels of the various genes are well correlated with each other between the various cell line datasets, implying that our original choice of the more ubiquitously expressed low-Gini-coefficient genes was indeed sound. In tissues, the Gini values and median expression levels of genes showed a greater variation, with the GC of genes changing with the number and types of tissues in the data sets. In all data sets, regardless of whether this was derived from tissues or cell lines, we also show that the GC is a robust measure of gene expression stability. Using the GC as a measure of expression stability we illustrate its utility to find tissue- and cell line-optimised housekeeping genes without any prior bias, that again include only a small number of previously reported housekeeping genes. We also independently confirmed this experimentally using RT-qPCR with 40 candidate GC genes in a panel of 10 cell lines. These were termed the Gini Genes. In many cases, the variation in the expression levels of classical reference genes is really quite huge (e.g. 44 fold for GAPDH in one data set), suggesting that the cure (of using them as normalising genes) may in some cases be worse than the disease (of not doing so). We recommend the present data-driven approach for the selection of reference genes by using the easy-to-calculate and robust GC.
Collapse
Affiliation(s)
- Marina Wright Muelas
- Department of Biochemistry, Institute of Integrative Biology, Faculty of Health and Life Sciences, University of Liverpool, Crown Street, Liverpool, L69 7ZB, UK.
| | - Farah Mughal
- Department of Biochemistry, Institute of Integrative Biology, Faculty of Health and Life Sciences, University of Liverpool, Crown Street, Liverpool, L69 7ZB, UK
| | - Steve O'Hagan
- School of Chemistry, Department of Chemistry, The Manchester Institute of Biotechnology 131, Princess Street, Manchester, M1 7DN, UK
- The Manchester Institute of Biotechnology, 131, Princess Street, Manchester, M1 7DN, UK
| | - Philip J Day
- The Manchester Institute of Biotechnology, 131, Princess Street, Manchester, M1 7DN, UK.
- Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, M13 9PL, UK.
| | - Douglas B Kell
- Department of Biochemistry, Institute of Integrative Biology, Faculty of Health and Life Sciences, University of Liverpool, Crown Street, Liverpool, L69 7ZB, UK.
- Novo Nordisk Foundation Centre for Biosustainability, Technical University of Denmark, 10 Building 220, Kemitorvet, 2800, Kgs. Lyngby, Denmark.
| |
Collapse
|
40
|
Ma M, Burd CG. Retrograde trafficking and plasma membrane recycling pathways of the budding yeast Saccharomyces cerevisiae. Traffic 2019; 21:45-59. [PMID: 31471931 DOI: 10.1111/tra.12693] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2019] [Revised: 08/23/2019] [Accepted: 08/27/2019] [Indexed: 02/06/2023]
Abstract
The endosomal system functions as a network of protein and lipid sorting stations that receives molecules from endocytic and secretory pathways and directs them to the lysosome for degradation, or exports them from the endosome via retrograde trafficking or plasma membrane recycling pathways. Retrograde trafficking pathways describe endosome-to-Golgi transport while plasma membrane recycling pathways describe trafficking routes that return endocytosed molecules to the plasma membrane. These pathways are crucial for lysosome biogenesis, nutrient acquisition and homeostasis and for the physiological functions of many types of specialized cells. Retrograde and recycling sorting machineries of eukaryotic cells were identified chiefly through genetic screens using the budding yeast Saccharomyces cerevisiae system and discovered to be highly conserved in structures and functions. In this review, we discuss advances regarding retrograde trafficking and recycling pathways, including new discoveries that challenge existing ideas about the organization of the endosomal system, as well as how these pathways intersect with cellular homeostasis pathways.
Collapse
Affiliation(s)
- Mengxiao Ma
- Department of Cell Biology, Yale School of Medicine, New Haven, Connecticut
| | - Christopher G Burd
- Department of Cell Biology, Yale School of Medicine, New Haven, Connecticut
| |
Collapse
|
41
|
Chen K, Healy MD, Collins BM. Towards a molecular understanding of endosomal trafficking by Retromer and Retriever. Traffic 2019; 20:465-478. [DOI: 10.1111/tra.12649] [Citation(s) in RCA: 92] [Impact Index Per Article: 18.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2019] [Revised: 04/15/2019] [Accepted: 04/15/2019] [Indexed: 12/16/2022]
Affiliation(s)
- Kai‐En Chen
- Institute for Molecular Bioscience University of Queensland St. Lucia Queensland Australia
| | - Michael D. Healy
- Institute for Molecular Bioscience University of Queensland St. Lucia Queensland Australia
| | - Brett M. Collins
- Institute for Molecular Bioscience University of Queensland St. Lucia Queensland Australia
| |
Collapse
|
42
|
Qian ZM, Ke Y. Brain iron transport. Biol Rev Camb Philos Soc 2019; 94:1672-1684. [PMID: 31190441 DOI: 10.1111/brv.12521] [Citation(s) in RCA: 69] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2018] [Revised: 04/22/2019] [Accepted: 04/24/2019] [Indexed: 12/19/2022]
Abstract
Brain iron is a crucial participant and regulator of normal physiological activity. However, excess iron is involved in the formation of free radicals, and has been associated with oxidative damage to neuronal and other brain cells. Abnormally high brain iron levels have been observed in various neurodegenerative diseases, including neurodegeneration with brain iron accumulation, Alzheimer's disease, Parkinson's disease and Huntington's disease. However, the key question of why iron levels increase in the relevant regions of the brain remains to be answered. A full understanding of the homeostatic mechanisms involved in brain iron transport and metabolism is therefore critical not only for elucidating the pathophysiological mechanisms responsible for excess iron accumulation in the brain but also for developing pharmacological interventions to disrupt the chain of pathological events occurring in these neurodegenerative diseases. Numerous studies have been conducted, but to date no effort to synthesize these studies and ideas into a systematic and coherent summary has been made, especially concerning iron transport across the luminal (apical) membrane of the capillary endothelium and the membranes of different brain cell types. Herein, we review key findings on brain iron transport, highlighting the mechanisms involved in iron transport across the luminal (apical) as well as the abluminal (basal) membrane of the blood-brain barrier, the blood-cerebrospinal fluid barrier, and iron uptake and release in neurons, oligodendrocytes, astrocytes and microglia within the brain. We offer suggestions for addressing the many important gaps in our understanding of this important topic, and provide new insights into the potential causes of abnormally increased iron levels in regions of the brain in neurodegenerative disorders.
Collapse
Affiliation(s)
- Zhong-Ming Qian
- Institute of Translational & Precision Medicine, Nantong University, Nantong, 226019, China.,Laboratory of Neuropharmacology, School of Pharmacy, & National Clinical Research Center for Aging and Medicine, Huashan Hospital, Fudan University, Shanghai, 201203, China
| | - Ya Ke
- School of Biomedical Sciences and Gerald Choa Neuroscience Centre, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, Hong Kong
| |
Collapse
|
43
|
Patel D, Xu C, Nagarajan S, Liu Z, Hemphill WO, Shi R, Uversky VN, Caldwell GA, Caldwell KA, Witt SN. Alpha-synuclein inhibits Snx3-retromer-mediated retrograde recycling of iron transporters in S. cerevisiae and C. elegans models of Parkinson's disease. Hum Mol Genet 2019; 27:1514-1532. [PMID: 29452354 DOI: 10.1093/hmg/ddy059] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2017] [Accepted: 02/12/2018] [Indexed: 01/31/2023] Open
Abstract
We probed the role of alpha-synuclein (α-syn) in modulating sorting nexin 3 (Snx3)-retromer-mediated recycling of iron transporters in Saccharomyces cerevisiae and Caenorhabditis elegans. In yeast, the membrane-bound heterodimer Fet3/Ftr1 is the high affinity iron importer. Fet3 is a membrane-bound multicopper ferroxidase, whose ferroxidase domain is orthologous to human ceruloplasmin (Cp), that oxidizes external Fe+2 to Fe+3; the Fe+3 ions then channel through the Ftr1 permease into the cell. When the concentration of external iron is low (<1 µM), Fet3/Ftr1 is maintained on the plasma membrane by retrograde endocytic-recycling; whereas, when the concentration of external iron is high (>10 µM), Fet3/Ftr1 is endocytosed and shunted to the vacuole for degradation. We discovered that α-syn expression phenocopies the high iron condition: under the low iron condition (<1 µM), α-syn inhibits Snx3-retromer-mediated recycling of Fet3/Ftr1 and instead shunts Fet3/Ftr1 into the multivesicular body pathway to the vacuole. α-Syn inhibits recycling by blocking the association of Snx3-mCherry molecules with endocytic vesicles, possibly by interfering with the binding of Snx3 to phosphatidylinositol-3-monophosphate. In C. elegans, transgenic worms expressing α-syn exhibit an age-dependent degeneration of dopaminergic neurons that is partially rescued by the iron chelator desferoxamine. This implies that α-syn-expressing dopaminergic neurons are susceptible to changes in iron neurotoxicity with age, whereby excess iron enhances α-syn-induced neurodegeneration. In vivo genetic analysis indicates that α-syn dysregulates iron homeostasis in worm dopaminergic neurons, possibly by inhibiting SNX-3-mediated recycling of a membrane-bound ortholog of Cp (F21D5.3), the iron exporter ferroportin (FPN1.1), or both.
Collapse
Affiliation(s)
- Dhaval Patel
- Department of Biochemistry and Molecular Biology, Louisiana State University Health Sciences Center, Shreveport, LA 71130, USA
| | - Chuan Xu
- Department of Biological Sciences, The University of Alabama, Tuscaloosa, AL 35487, USA
| | - Sureshbabu Nagarajan
- Department of Biochemistry and Molecular Biology, Louisiana State University Health Sciences Center, Shreveport, LA 71130, USA
| | - Zhengchang Liu
- Department of Biological Sciences, The University of New Orleans, New Orleans, LA 70148, USA
| | - Wayne O Hemphill
- Department of Biochemistry and Molecular Biology, Louisiana State University Health Sciences Center, Shreveport, LA 71130, USA
| | - Runhua Shi
- Department of Medicine, Feist-Weiller Cancer Center, Louisiana State University Health Sciences Center, Shreveport, LA 71130, USA
| | - Vladimir N Uversky
- Department of Molecular Medicine, USF Health Byrd Alzheimer's Research Institute, Morsani College of Medicine, University of South Florida, Tampa, FL 33612, USA
| | - Guy A Caldwell
- Department of Biological Sciences, The University of Alabama, Tuscaloosa, AL 35487, USA
| | - Kim A Caldwell
- Department of Biological Sciences, The University of Alabama, Tuscaloosa, AL 35487, USA
| | - Stephan N Witt
- Department of Biochemistry and Molecular Biology, Louisiana State University Health Sciences Center, Shreveport, LA 71130, USA.,Pharmacology, Toxicology and Neuroscience, Louisiana State University Health Sciences Center, Shreveport, LA 71130, USA
| |
Collapse
|
44
|
A promising new approach to cancer therapy: Targeting iron metabolism in cancer stem cells. Semin Cancer Biol 2018; 53:125-138. [DOI: 10.1016/j.semcancer.2018.07.009] [Citation(s) in RCA: 63] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2018] [Revised: 07/24/2018] [Accepted: 07/25/2018] [Indexed: 12/15/2022]
|
45
|
Cullen PJ, Steinberg F. To degrade or not to degrade: mechanisms and significance of endocytic recycling. Nat Rev Mol Cell Biol 2018; 19:679-696. [PMID: 30194414 DOI: 10.1038/s41580-018-0053-7] [Citation(s) in RCA: 314] [Impact Index Per Article: 52.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Newly endocytosed integral cell surface proteins are typically either directed for degradation or subjected to recycling back to the plasma membrane. The sorting of integral cell surface proteins, including signalling receptors, nutrient transporters, ion channels, adhesion molecules and polarity markers, within the endolysosomal network for recycling is increasingly recognized as an essential feature in regulating the complexities of physiology at the cell, tissue and organism levels. Historically, endocytic recycling has been regarded as a relatively passive process, where the majority of internalized integral proteins are recycled via a nonspecific sequence-independent 'bulk membrane flow' pathway. Recent work has increasingly challenged this view. The discovery of sequence-specific sorting motifs and the identification of cargo adaptors and associated coat complexes have begun to uncover the highly orchestrated nature of endosomal cargo recycling, thereby providing new insight into the function and (patho)physiology of this process.
Collapse
Affiliation(s)
- Peter J Cullen
- School of Biochemistry, Biomedical Sciences Building, University of Bristol, Bristol, UK.
| | - Florian Steinberg
- Center for Biological Systems Analysis, Albert Ludwigs Universitaet Freiburg, Freiburg im Breisgau, Germany.
| |
Collapse
|
46
|
Yien YY, Shi J, Chen C, Cheung JTM, Grillo AS, Shrestha R, Li L, Zhang X, Kafina MD, Kingsley PD, King MJ, Ablain J, Li H, Zon LI, Palis J, Burke MD, Bauer DE, Orkin SH, Koehler CM, Phillips JD, Kaplan J, Ward DM, Lodish HF, Paw BH. FAM210B is an erythropoietin target and regulates erythroid heme synthesis by controlling mitochondrial iron import and ferrochelatase activity. J Biol Chem 2018; 293:19797-19811. [PMID: 30366982 DOI: 10.1074/jbc.ra118.002742] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2018] [Revised: 09/11/2018] [Indexed: 01/01/2023] Open
Abstract
Erythropoietin (EPO) signaling is critical to many processes essential to terminal erythropoiesis. Despite the centrality of iron metabolism to erythropoiesis, the mechanisms by which EPO regulates iron status are not well-understood. To this end, here we profiled gene expression in EPO-treated 32D pro-B cells and developing fetal liver erythroid cells to identify additional iron regulatory genes. We determined that FAM210B, a mitochondrial inner-membrane protein, is essential for hemoglobinization, proliferation, and enucleation during terminal erythroid maturation. Fam210b deficiency led to defects in mitochondrial iron uptake, heme synthesis, and iron-sulfur cluster formation. These defects were corrected with a lipid-soluble, small-molecule iron transporter, hinokitiol, in Fam210b-deficient murine erythroid cells and zebrafish morphants. Genetic complementation experiments revealed that FAM210B is not a mitochondrial iron transporter but is required for adequate mitochondrial iron import to sustain heme synthesis and iron-sulfur cluster formation during erythroid differentiation. FAM210B was also required for maximal ferrochelatase activity in differentiating erythroid cells. We propose that FAM210B functions as an adaptor protein that facilitates the formation of an oligomeric mitochondrial iron transport complex, required for the increase in iron acquisition for heme synthesis during terminal erythropoiesis. Collectively, our results reveal a critical mechanism by which EPO signaling regulates terminal erythropoiesis and iron metabolism.
Collapse
Affiliation(s)
- Yvette Y Yien
- From the Department of Biological Sciences, University of Delaware, Newark, Delaware 19716, .,the Division of Hematology, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts 02115
| | - Jiahai Shi
- the Whitehead Institute and Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139
| | - Caiyong Chen
- the Division of Hematology, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts 02115
| | - Jesmine T M Cheung
- the Department of Chemistry and Biochemistry, UCLA, Los Angeles, California 90095
| | - Anthony S Grillo
- the Department of Chemistry and Biochemistry, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801
| | - Rishna Shrestha
- the Department of Pathology, University of Utah School of Medicine, Salt Lake City, Utah 84112
| | - Liangtao Li
- the Department of Pathology, University of Utah School of Medicine, Salt Lake City, Utah 84112
| | - Xuedi Zhang
- From the Department of Biological Sciences, University of Delaware, Newark, Delaware 19716
| | - Martin D Kafina
- the Division of Hematology, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts 02115
| | - Paul D Kingsley
- the Center for Pediatric Biomedical Research, Department of Pediatrics, University of Rochester Medical Center, Rochester, New York 14642
| | - Matthew J King
- the Division of Hematology, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts 02115
| | - Julien Ablain
- the Division of Hematology-Oncology, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts 02115
| | - Hojun Li
- the Whitehead Institute and Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139
| | - Leonard I Zon
- the Division of Hematology-Oncology, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts 02115.,the Department of Pediatric Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, Massachusetts 02115, and
| | - James Palis
- the Center for Pediatric Biomedical Research, Department of Pediatrics, University of Rochester Medical Center, Rochester, New York 14642
| | - Martin D Burke
- the Department of Chemistry and Biochemistry, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801
| | - Daniel E Bauer
- the Division of Hematology-Oncology, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts 02115.,the Department of Pediatric Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, Massachusetts 02115, and
| | - Stuart H Orkin
- the Division of Hematology-Oncology, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts 02115.,the Department of Pediatric Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, Massachusetts 02115, and
| | - Carla M Koehler
- the Department of Chemistry and Biochemistry, UCLA, Los Angeles, California 90095
| | - John D Phillips
- the Division of Hematology and Hematologic Malignancy, University of Utah School of Medicine, Salt Lake City, Utah 84112
| | - Jerry Kaplan
- the Department of Pathology, University of Utah School of Medicine, Salt Lake City, Utah 84112
| | - Diane M Ward
- the Department of Pathology, University of Utah School of Medicine, Salt Lake City, Utah 84112
| | - Harvey F Lodish
- the Whitehead Institute and Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139
| | - Barry H Paw
- the Division of Hematology, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts 02115.,the Division of Hematology-Oncology, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts 02115.,the Department of Pediatric Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, Massachusetts 02115, and
| |
Collapse
|
47
|
Lin G, Lee PT, Chen K, Mao D, Tan KL, Zuo Z, Lin WW, Wang L, Bellen HJ. Phospholipase PLA2G6, a Parkinsonism-Associated Gene, Affects Vps26 and Vps35, Retromer Function, and Ceramide Levels, Similar to α-Synuclein Gain. Cell Metab 2018; 28:605-618.e6. [PMID: 29909971 DOI: 10.1016/j.cmet.2018.05.019] [Citation(s) in RCA: 118] [Impact Index Per Article: 19.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/18/2017] [Revised: 03/23/2018] [Accepted: 05/22/2018] [Indexed: 11/16/2022]
Abstract
Mutations in PLA2G6 (PARK14) cause neurodegenerative disorders in humans, including autosomal recessive neuroaxonal dystrophy and early-onset parkinsonism. We show that loss of iPLA2-VIA, the fly homolog of PLA2G6, reduces lifespan, impairs synaptic transmission, and causes neurodegeneration. Phospholipases typically hydrolyze glycerol phospholipids, but loss of iPLA2-VIA does not affect the phospholipid composition of brain tissue but rather causes an elevation in ceramides. Reducing ceramides with drugs, including myriocin or desipramine, alleviates lysosomal stress and suppresses neurodegeneration. iPLA2-VIA binds the retromer subunits Vps35 and Vps26 and enhances retromer function to promote protein and lipid recycling. Loss of iPLA2-VIA impairs retromer function, leading to a progressive increase in ceramide. This induces a positive feedback loop that affects membrane fluidity and impairs retromer function and neuronal function. Similar defects are observed upon loss of vps26 or vps35 or overexpression of α-synuclein, indicating that these defects may be common in Parkinson disease.
Collapse
Affiliation(s)
- Guang Lin
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA; Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX 77030, USA
| | - Pei-Tseng Lee
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA; Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX 77030, USA
| | - Kuchuan Chen
- Program in Developmental Biology, Baylor College of Medicine, Houston, TX 77030, USA; Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX 77030, USA
| | - Dongxue Mao
- Program in Developmental Biology, Baylor College of Medicine, Houston, TX 77030, USA; Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX 77030, USA
| | - Kai Li Tan
- Program in Developmental Biology, Baylor College of Medicine, Houston, TX 77030, USA; Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX 77030, USA
| | - Zhongyuan Zuo
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA; Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX 77030, USA
| | - Wen-Wen Lin
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA; Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX 77030, USA
| | - Liping Wang
- Program in Developmental Biology, Baylor College of Medicine, Houston, TX 77030, USA; Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX 77030, USA
| | - Hugo J Bellen
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA; Program in Developmental Biology, Baylor College of Medicine, Houston, TX 77030, USA; Howard Hughes Medical Institute, Baylor College of Medicine, Houston, TX 77030, USA; Department of Neuroscience, Baylor College of Medicine, Houston, TX 77030, USA; Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX 77030, USA.
| |
Collapse
|
48
|
Hrg1 promotes heme-iron recycling during hemolysis in the zebrafish kidney. PLoS Genet 2018; 14:e1007665. [PMID: 30248094 PMCID: PMC6171960 DOI: 10.1371/journal.pgen.1007665] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2018] [Revised: 10/04/2018] [Accepted: 08/28/2018] [Indexed: 12/16/2022] Open
Abstract
Heme-iron recycling from senescent red blood cells (erythrophagocytosis) accounts for the majority of total body iron in humans. Studies in cultured cells have ascribed a role for HRG1/SLC48A1 in heme-iron transport but the in vivo function of this heme transporter is unclear. Here we present genetic evidence in a zebrafish model that Hrg1 is essential for macrophage-mediated heme-iron recycling during erythrophagocytosis in the kidney. Furthermore, we show that zebrafish Hrg1a and its paralog Hrg1b are functional heme transporters, and genetic ablation of both transporters in double knockout (DKO) animals shows lower iron accumulation concomitant with higher amounts of heme sequestered in kidney macrophages. RNA-seq analyses of DKO kidney revealed large-scale perturbation in genes related to heme, iron metabolism and immune functions. Taken together, our results establish the kidney as the major organ for erythrophagocytosis and identify Hrg1 as an important regulator of heme-iron recycling by macrophages in the adult zebrafish. Total body iron stores in mammals is a composite of iron absorption from diet and iron recycled by macrophages from dying red blood cells (RBCs). Upon erythrophagocytosis of RBCs, the hemoglobin is degraded and heme is imported from the phagosomal compartment into the cytoplasm so that the iron can be released from heme. Defects in these pathways can lead to aberrant iron homeostasis. The Heme Responsive Gene-1 (HRG1, SLC48A1) was identified previously as a heme importer in the intestine of the roundworm, Caenorhabditis elegans. In cell culture studies, HRG1 was demonstrated to mobilize heme from the erythrophagosome of mouse macrophages into the cytosol. However, the in vivo function of HRG1 remains to be elucidated. The zebrafish is a powerful genetic animal model for studying vertebrate development and ontogeny of hematopoiesis. In zebrafish, the kidney marrow is the adult hematopoietic organ that is functionally analogous to the mammalian bone marrow. In this study, we show that Hrg1 plays an essential in vivo role in recycling of damaged RBCs, and that the kidney macrophages are primarily responsible for recycling heme-iron in the adult zebrafish.
Collapse
|
49
|
McGough IJ, de Groot REA, Jellett AP, Betist MC, Varandas KC, Danson CM, Heesom KJ, Korswagen HC, Cullen PJ. SNX3-retromer requires an evolutionary conserved MON2:DOPEY2:ATP9A complex to mediate Wntless sorting and Wnt secretion. Nat Commun 2018; 9:3737. [PMID: 30213940 PMCID: PMC6137200 DOI: 10.1038/s41467-018-06114-3] [Citation(s) in RCA: 49] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2017] [Accepted: 08/13/2018] [Indexed: 12/28/2022] Open
Abstract
Wntless transports Wnt morphogens to the cell surface and is required for Wnt secretion and morphogenic gradients formation. Recycling of endocytosed Wntless requires the sorting nexin-3 (SNX3)-retromer-dependent endosome-to-Golgi transport pathway. Here we demonstrate the essential role of SNX3-retromer assembly for Wntless transport and report that SNX3 associates with an evolutionary conserved endosome-associated membrane re-modelling complex composed of MON2, DOPEY2 and the putative aminophospholipid translocase, ATP9A. In vivo suppression of Ce-mon-2, Ce-pad-1 or Ce-tat-5 (respective MON2, DOPEY2 and ATP9A orthologues) phenocopy a loss of SNX3-retromer function, leading to enhanced lysosomal degradation of Wntless and a Wnt phenotype. Perturbed Wnt signalling is also observed upon overexpression of an ATPase-inhibited TAT-5(E246Q) mutant, suggesting a role for phospholipid flippase activity during SNX3-retromer-mediated Wntless sorting. Together, these findings provide in vitro and in vivo mechanistic details to describe SNX3-retromer-mediated transport during Wnt secretion and the formation of Wnt-morphogenic gradients.
Collapse
Affiliation(s)
- Ian J McGough
- School of Biochemistry, University of Bristol, Bristol, BS8 1TD, UK
- The Francis Crick Institute, 1 Midland Rd, London, NW1 1AT, UK
| | - Reinoud E A de Groot
- Hubrecht Institute, Royal Netherlands Academy of Arts and Sciences and University Medical Center Utrecht, Uppsalalaan 8, Utrecht, 3584 CT, The Netherlands
| | - Adam P Jellett
- School of Biochemistry, University of Bristol, Bristol, BS8 1TD, UK
| | - Marco C Betist
- Hubrecht Institute, Royal Netherlands Academy of Arts and Sciences and University Medical Center Utrecht, Uppsalalaan 8, Utrecht, 3584 CT, The Netherlands
| | - Katherine C Varandas
- Program in Cell Biology, University of California, San Francisco, 16th Street, San Francisco, CA, 94158, USA
- Laboratory of Developmental Genetics, The Rockefeller University, 1230 York Avenue, New York, NY, 10065, USA
| | - Chris M Danson
- School of Biochemistry, University of Bristol, Bristol, BS8 1TD, UK
| | - Kate J Heesom
- Proteomics Facility, School of Biochemistry, University of Bristol, Bristol, BS8 1TD, UK
| | - Hendrik C Korswagen
- Hubrecht Institute, Royal Netherlands Academy of Arts and Sciences and University Medical Center Utrecht, Uppsalalaan 8, Utrecht, 3584 CT, The Netherlands.
| | - Peter J Cullen
- School of Biochemistry, University of Bristol, Bristol, BS8 1TD, UK.
| |
Collapse
|
50
|
Naslavsky N, Caplan S. The enigmatic endosome - sorting the ins and outs of endocytic trafficking. J Cell Sci 2018; 131:131/13/jcs216499. [PMID: 29980602 DOI: 10.1242/jcs.216499] [Citation(s) in RCA: 199] [Impact Index Per Article: 33.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
The early endosome (EE), also known as the sorting endosome (SE) is a crucial station for the sorting of cargoes, such as receptors and lipids, through the endocytic pathways. The term endosome relates to the receptacle-like nature of this organelle, to which endocytosed cargoes are funneled upon internalization from the plasma membrane. Having been delivered by the fusion of internalized vesicles with the EE or SE, cargo molecules are then sorted to a variety of endocytic pathways, including the endo-lysosomal pathway for degradation, direct or rapid recycling to the plasma membrane, and to a slower recycling pathway that involves a specialized form of endosome known as a recycling endosome (RE), often localized to the perinuclear endocytic recycling compartment (ERC). It is striking that 'the endosome', which plays such essential cellular roles, has managed to avoid a precise description, and its characteristics remain ambiguous and heterogeneous. Moreover, despite the rapid advances in scientific methodologies, including breakthroughs in light microscopy, overall, the endosome remains poorly defined. This Review will attempt to collate key characteristics of the different types of endosomes and provide a platform for discussion of this unique and fascinating collection of organelles. Moreover, under-developed, poorly understood and important open questions will be discussed.
Collapse
Affiliation(s)
- Naava Naslavsky
- The Department of Biochemistry and Molecular Biology, The University of Nebraska Medical Center, Omaha, NE 68198, USA
| | - Steve Caplan
- The Department of Biochemistry and Molecular Biology, The University of Nebraska Medical Center, Omaha, NE 68198, USA .,The Fred and Pamela Buffett Cancer Center, The University of Nebraska Medical Center, Omaha, NE 68198, USA
| |
Collapse
|