21 results on '"Rukmini Mukherjee"'
Search Results
2. TBC1D15 potentiates lysosomal regeneration from damaged membranes
- Author
-
Anshu Bhattacharya, Rukmini Mukherjee, Santosh Kumar Kuncha, Melinda Brunstein, Rajeshwari Rathore, Stephan Junek, Christian Münch, and Ivan Dikic
- Abstract
Acute lysosomal membrane damage reduces the cellular population of functional lysosomes. However, these damaged lysosomes have a remarkable recovery potential independent of lysosomal biogenesis and remain unaffected in TFEB/TFE3-depleted cells. We combined proximity labelling based proteomics, biochemistry and high-resolution microscopy to unravel a new lysosomal membrane regeneration pathway which is dependent on ATG8, lysosomal membrane protein LIMP2, the Rab7 GAP TBC1D15, and proteins required for autophagic lysosomal reformation (ALR) including Dynamin2, Kinesin5B and Clathrin. Upon lysosomal damage, LIMP2 act as a lysophagy receptor to bind ATG8, which in turn recruits TBC1D15 to damaged membranes. TBC1D15 hydrolyses Rab7-GTP to segregate the damaged lysosomal mass and provides a scaffold to assemble and stabilize the ALR machinery, potentiating the formation of lysosomal tubules and subsequent Dynamin2-dependent scission. TBC1D15-mediated lysosome regeneration was also observed in a cell culture model of oxalate nephropathy.
- Published
- 2022
3. Regulation of Host-Pathogen Interactions via the Ubiquitin System
- Author
-
Rukmini Mukherjee and Ivan Dikic
- Subjects
Bacteria ,Ubiquitin ,Virulence Factors ,Ubiquitin-Protein Ligases ,Host-Pathogen Interactions ,Ubiquitination ,Microbiology ,Immunity, Innate - Abstract
Ubiquitination is a posttranslational modification that regulates a multitude of cellular functions. Pathogens, such as bacteria and viruses, have evolved sophisticated mechanisms that evade or counteract ubiquitin-dependent host responses, or even exploit the ubiquitin system to their own advantage. This is largely done by numerous pathogen virulence factors that encode E3 ligases and deubiquitinases, which are often used as weapons in pathogen–host cell interactions. Moreover, upon pathogen attack, host cellular signaling networks undergo major ubiquitin-dependent changes to protect the host cell, including coordination of innate immunity, remodeling of cellular organelles, reorganization of the cytoskeleton, and reprogramming of metabolic pathways to restrict growth of the pathogen. Here we provide mechanistic insights into ubiquitin regulation of host-pathogen interactions and how it affects bacterial and viral pathogenesis and the organization and response of the host cell.
- Published
- 2022
4. RETREG1/FAM134B mediated autophagosomal degradation of AMFR/GP78 and OPA1 —a dual organellar turnover mechanism
- Author
-
Rukmini Mukherjee, Subhrangshu Das, Swadhin Chandra Jana, Manindra Bera, Debdatto Mookherjee, Oishee Chakrabarti, and Saikat Chakrabarti
- Subjects
0301 basic medicine ,Mitochondrion ,Biology ,Real-Time Polymerase Chain Reaction ,GTP Phosphohydrolases ,03 medical and health sciences ,Microscopy, Electron, Transmission ,Cell Line, Tumor ,Chlorocebus aethiops ,Organelle ,Animals ,Humans ,Molecular Biology ,Microscopy, Confocal ,030102 biochemistry & molecular biology ,Mechanism (biology) ,Endoplasmic reticulum ,Autophagy ,Autophagosomes ,Intracellular Signaling Peptides and Proteins ,Membrane Proteins ,Cell Biology ,DUAL (cognitive architecture) ,Cell biology ,Receptors, Autocrine Motility Factor ,030104 developmental biology ,Mitoplast ,Gene Knockdown Techniques ,COS Cells ,Degradation (geology) ,Lysosomes ,HeLa Cells ,Research Paper - Abstract
Turnover of cellular organelles, including endoplasmic reticulum (ER) and mitochondria, is orchestrated by an efficient cellular surveillance system. We have identified a mechanism for dual regulation of ER and mitochondria under stress. It is known that AMFR, an ER E3 ligase and ER-associated degradation (ERAD) regulator, degrades outer mitochondrial membrane (OMM) proteins, MFNs (mitofusins), via the proteasome and triggers mitophagy. We show that destabilized mitochondria are almost devoid of the OMM and generate “mitoplasts”. This brings the inner mitochondrial membrane (IMM) in the proximity of the ER. When AMFR levels are high and the mitochondria are stressed, the reticulophagy regulatory protein RETREG1 participates in the formation of the mitophagophore by interacting with OPA1. Interestingly, OPA1 and other IMM proteins exhibit similar RETREG1-dependent autophagosomal degradation as AMFR, unlike most of the OMM proteins. The “mitoplasts” generated are degraded by reticulo-mito-phagy – simultaneously affecting dual organelle turnover. Abbreviations: AMFR/GP78: autocrine motility factor receptor; BAPTA: 1,2-bis(o-aminophenoxy)ethane-N,N,N′,N′-tetraacetic acid; BFP: blue fluorescent protein; CCCP: carbonyl cyanide m-chlorophenyl hydrazone; CNBr: cyanogen bromide; ER: endoplasmic reticulum; ERAD: endoplasmic-reticulum-associated protein degradation; FL: fluorescence, GFP: green fluorescent protein; HA: hemagglutinin; HEPES: 4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid; IMM: inner mitochondrial membrane; LIR: LC3-interacting region; MAP1LC3/LC3: microtubule associated protein 1 light chain 3; MFN: mitofusin, MGRN1: mahogunin ring finger 1; NA: numerical aperature; OMM: outer mitochondrial membrane; OPA1: OPA1 mitochondrial dynamin like GTPase; PRNP/PrP: prion protein; RER: rough endoplasmic reticulum; RETREG1/FAM134B: reticulophagy regulator 1; RFP: red fluorescent protein; RING: really interesting new gene; ROI: region of interest; RTN: reticulon; SEM: standard error of the mean; SER: smooth endoplasmic reticulum; SIM: structured illumination microscopy; SQSTM1/p62: sequestosome 1; STED: stimulated emission depletion; STOML2: stomatin like 2; TOMM20: translocase of outer mitochondrial membrane 20; UPR: unfolded protein response.
- Published
- 2020
5. Serine-ubiquitination regulates Golgi morphology and the secretory pathway upon Legionella infection
- Author
-
Thomas Colby, Mike Heilemann, Marius Glogger, Florian Bonn, Ivan Dikic, Rukmini Mukherjee, Yaobin Liu, and Ivan Matic
- Subjects
Legionella ,medicine.medical_treatment ,Golgi Apparatus ,Vacuole ,Biochemistry ,Article ,Serine ,03 medical and health sciences ,symbols.namesake ,0302 clinical medicine ,Ubiquitin ,ddc:570 ,medicine ,Humans ,ddc:610 ,Fragmentation (cell biology) ,Molecular Biology ,Secretory pathway ,Host protein ,030304 developmental biology ,0303 health sciences ,biology ,Effector ,Chemistry ,Ubiquitination ,Cell Biology ,Golgi apparatus ,biology.organism_classification ,Cell biology ,Cytokine ,symbols ,biology.protein ,030217 neurology & neurosurgery - Abstract
SidE family of Legionella effectors catalyze non-canonical phosphoribosyl-linked ubiquitination (PR-ubiquitination) of host proteins during bacterial infection. SdeA localizes predominantly to ER and partially to the Golgi apparatus, and mediates serine ubiquitination of multiple ER and Golgi proteins. Here we show that SdeA causes disruption of Golgi integrity due to its ubiquitin ligase activity. The Golgi linking proteins GRASP55 and GRASP65 are PR-ubiquitinated on multiple serine residues, thus preventing their ability to cluster and form oligomeric structures. In addition, we found that the functional consequence of Golgi disruption is not linked to the recruitment of Golgi membranes to the growing Legionella-containing vacuoles. Instead, it affects the secretory pathway, including cytokine release in cells. Taken together, our study sheds light on the Golgi manipulation strategy by which Legionella hijacks the secretory pathway and promotes bacterial infection.
- Published
- 2021
- Full Text
- View/download PDF
6. Characterization of protease activity of Nsp3 from SARS-CoV-2 and its in vitro inhibition by nanobodies
- Author
-
Stephen P. Matthews, Ivan Dikic, Sven M. Lange, Anthony G. Hope, Lee A. Armstrong, David W. Gray, Denisa Bojkova, Rukmini Mukherjee, Fraser Cunningham, Virginia De Cesare, Paul G. Wyatt, Yogesh Kulathu, Isobel Cole, Jindrich Cinatl, Paul Davies, Rachel Toth, Raja Sekar Nirujogi, and Franz S. Gruber
- Subjects
Protease ,Chemistry ,Viral protein ,viruses ,medicine.medical_treatment ,medicine.disease_cause ,ISG15 ,Interactome ,In vitro ,Transmembrane protein ,Cell biology ,Viral life cycle ,medicine ,Binding site - Abstract
Of the 16 non-structural proteins (Nsps) encoded by SARS CoV-2, Nsp3 is the largest and plays important roles in the viral life cycle. Being a large, multidomain, transmembrane protein, Nsp3 has been the most challenging Nsp to characterize. Encoded within Nsp3 is the papain-like protease PLpro domain that cleaves not only the viral protein but also polyubiquitin and the ubiquitin-like modifier ISG15 from host cells. We here compare the interactors of PLpro and Nsp3 and find a largely overlapping interactome. Intriguingly, we find that near full length Nsp3 is a more active protease compared to the minimal catalytic domain of PLpro. Using a MALDI-TOF based assay, we screen 1971 approved clinical compounds and identify five compounds that inhibit PLpro with IC50s in the low micromolar range but showed cross reactivity with other human deubiquitinases and had no significant antiviral activity in cellular SARS-CoV-2 infection assays. We therefore looked for alternative methods to block PLpro activity and engineered competitive nanobodies that bind to PLpro at the substrate binding site with nanomolar affinity thus inhibiting the enzyme. Our work highlights the importance of studying Nsp3 and provides tools and valuable insights to investigate Nsp3 biology during the viral infection cycle.
- Published
- 2020
7. Inhibition of papain-like protease PLpro blocks SARS-CoV-2 spread and promotes anti-viral immunity
- Author
-
Marek Widera, Sandra Ciesek, Huib Ovaa, Ivan Dikic, Gerbrand J. van der Heden van Noort, Krishnaraj Rajalingam, Donghyuk Shin, Diana Grewe, Ahmad Reza Mehdipour, Laura Schulz, Georg Tascher, Anshu Bhattacharya, Jindrich Cinatl, Klaus-Peter Knobeloch, Denisa Bojkova, Kheewoong Baek, Gerhard Hummer, Paul P. Geurink, Rukmini Mukherjee, and Brenda A. Schulman
- Subjects
Papain ,chemistry.chemical_compound ,Protease ,chemistry ,Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) ,medicine.medical_treatment ,medicine ,Anti viral immunity ,Virology - Abstract
Main protease and papain-like protease (PLpro) are essential coronaviral enzymes required for polypeptide processing during viral maturation. PLpro additionally cleaves proteinous post-translational modifications from host proteins to evade anti-viral immune responses. Here, we provide biochemical, structural and functional characterizations of PLpro from SARS-CoV-2 (PLproCoV2) and reveal differences to that of SARS (PLproSARS) in controlling interferon (IFN) and NF-kB pathways. PLproCoV2 and PLproSARS share 83% sequence identity, yet they differ in their host substrate preferences: PLproCoV2 predominantly cleaves the ubiquitin-like protein ISG15 off from host proteins, while PLproSARS preferentially targets ubiquitin chains. The crystal structure of PLproCoV2 in complex with ISG15 explains the affinity and higher specificity through distinctive binding to ISG15’s unique amino-terminal ubiquitin-like domain, and enabled the identification of GRL-0617 as a non-covalent candidate inhibitor for PLproCoV2. In human cells, PLproCoV2 cleaves ISG15 from interferon responsive factor 3 (IRF3), blocks its nuclear translocation, and reduces type I interferon responses, whereas PLproSARS preferentially mediates deubiquitination of critical components of the NF-kB pathway. Pharmacological inhibition of PLproCoV2 blocks the virus-induced cytopathogenic effect upon infection with SARS-CoV-2, fosters the anti- viral interferon pathway and reduces viral release from infected cells. We propose that therapeutic targeting of PLproCoV2 can suppress SARS-CoV-2 infection and promote anti-viral immunity.
- Published
- 2020
8. Calmodulin regulates MGRN1‐GP78 interaction mediated ubiquitin proteasomal degradation system
- Author
-
Samita Basu, Oishee Chakrabarti, Saikat Chakrabarti, Abhishek Sau, Rukmini Mukherjee, and Anshu Bhattacharya
- Subjects
0301 basic medicine ,Proteasome Endopeptidase Complex ,Cell biology ,Calmodulin ,Ubiquitin-Protein Ligases ,Protein degradation ,Biochemistry ,Mice ,03 medical and health sciences ,0302 clinical medicine ,Endocrinology ,Ubiquitin ,Mitophagy ,Genetics ,Animals ,Humans ,Calcium Signaling ,Molecular Biology ,Internal medicine ,Neurons ,biology ,Proteasome ,Chemistry ,Endoplasmic reticulum ,Signal transducing adaptor protein ,Ubiquitin ligase ,Molecular Docking Simulation ,Receptors, Autocrine Motility Factor ,030104 developmental biology ,Proteolysis ,biology.protein ,Calcium ,030217 neurology & neurosurgery ,HeLa Cells ,Biotechnology - Abstract
The mechanism by which the endoplasmic reticulum (ER) ubiquitin ligases sense stress to potentiate their activity is poorly understood. GP78, an ER E3 ligase, is best known for its role in ER-associated protein degradation, although its activity is also linked to mitophagy, ER-mitochondria junctions, and MAPK signaling, thus highlighting the importance of understanding its regulation. In healthy cells, Mahogunin really interesting new gene (RING) finger 1 (MGRN1) interacts with GP78 and proteasomally degrades it to alleviate mitophagy. Here, we identify calmodulin (CaM) as the adapter protein that senses fluctuating cytosolic Ca2+ levels and modulates the Ca2+-dependent MGRN1-GP78 interactions. When stress elevates cytosolic Ca2+ levels in cultured and primary neuronal cells, CaM binds to both E3 ligases and inhibits their interaction. Molecular docking, simulation, and biophysical studies show that CaM interacts with both proteins with different affinities and binding modes. The physiological impact of this interaction switch manifests in the regulation of ER-associated protein degradation, ER-mitochondria junctions, and relative distribution of smooth ER and rough ER.-Mukherjee, R., Bhattacharya, A., Sau, A., Basu, S., Chakrabarti, S., Chakrabarti, O. Calmodulin regulates MGRN1-GP78 interaction mediated ubiquitin proteasomal degradation system.
- Published
- 2018
- Full Text
- View/download PDF
9. NIPSNAP Beacons in Mitophagy
- Author
-
Rukmini Mukherjee and Ivan Dikic
- Subjects
0303 health sciences ,biology ,Autophagy ,Mitophagy ,Cell Biology ,Mitochondrion ,biology.organism_classification ,General Biochemistry, Genetics and Molecular Biology ,Mitochondria ,Cell biology ,Selective autophagy ,03 medical and health sciences ,0302 clinical medicine ,Receptor ,Molecular Biology ,Zebrafish ,030217 neurology & neurosurgery ,030304 developmental biology ,Developmental Biology - Abstract
In healthy cells, dysfunctional mitochondria are removed by selective autophagy (mitophagy), impairment of which causes disease. In this issue of Developmental Cell, Princely Abudu et al. (2019) delineate the function of NIPSNAP1 and NIPSNAP2 in recruiting mitophagy receptors to depolarized mitochondria, highlighting their importance in the zebrafish brain.
- Published
- 2019
10. MGRN1-mediated ubiquitination ofα-tubulin regulates microtubule dynamics and intracellular transport
- Author
-
Rukmini Mukherjee, Priyanka Majumder, and Oishee Chakrabarti
- Subjects
0301 basic medicine ,Genetically modified mouse ,Endosome ,Ubiquitin-Protein Ligases ,Mutant ,Biology ,Mitochondrion ,Microtubules ,Biochemistry ,03 medical and health sciences ,Ubiquitin ,Tubulin ,Structural Biology ,Microtubule ,Genetics ,medicine ,Humans ,Molecular Biology ,Mitosis ,Endosomal Sorting Complexes Required for Transport ,Neurodegeneration ,Ubiquitination ,Biological Transport ,Cell Biology ,medicine.disease ,Mitochondria ,Cell biology ,DNA-Binding Proteins ,030104 developmental biology ,biology.protein ,HeLa Cells - Abstract
MGRN1-mediated ubiquitination of α-tubulin regulates microtubule stability and mitotic spindle positioning in mitotic cells. This study elucidates the effect of MGRN1-mediated ubiquitination of α-tubulin in interphase cells. Here, we show that MGRN1-mediated ubiquitination regulates dynamics of EB1-labeled plus ends of microtubules. Intracellular transport of mitochondria and endosomes are affected in cultured cells where functional MGRN1 is depleted. Defects in microtubule-dependent organellar transport are evident in cells where noncanonical K6-mediated ubiquitination of α-tubulin by MGRN1 is compromised. Loss of MGRN1 has been previously correlated with late-onset spongiform neurodegeneration. Mislocalised cytosolically exposed PrP (Ctm PrP) interacts with MGRN1 leading to its loss of function. Expression of Ctm PrP generating mutants of PrP[PrP(A117V) and PrP(KHII)] lead to decrease in MGRN1-mediated ubiquitination of α-tubulin and intracellular transport defects. Brain lysates from PrP(A117V) transgenic mice also indicate loss of tubulin polymerization as compared to non-transgenic controls. Depletion of MGRN1 activity may hamper physiologically important processes like mitochondrial movement in neuronal processes and intracellular transport of ligands through the endosomal pathway thereby contributing to the pathogenesis of neurodegeneration in certain types of prion diseases.
- Published
- 2017
11. Calcium dependent regulation of protein ubiquitination – Interplay between E3 ligases and calcium binding proteins
- Author
-
Oishee Chakrabarti, Aneesha Das, Rukmini Mukherjee, and Saikat Chakrabarti
- Subjects
0301 basic medicine ,Ubiquitin-Protein Ligases ,chemistry.chemical_element ,NEDD4 ,Calcium ,Calcium in biology ,03 medical and health sciences ,SCF complex ,Calmodulin ,Calcium-binding protein ,Animals ,Humans ,Calcium Signaling ,Protein Interaction Maps ,Molecular Biology ,Calcium signaling ,biology ,Ubiquitination ,Cell Biology ,Protein ubiquitination ,Ubiquitin ligase ,Cell biology ,030104 developmental biology ,chemistry ,Biochemistry ,biology.protein - Abstract
The ubiquitination status of proteins and intracellular calcium levels are two factors which keep changing inside any living cell. These two events appear to be independent of each other but recent experimental evidences show that ubiquitination of cellular proteins are influenced by calcium, Calmodulin, Calmodulin-dependent kinase II and other proteins of calcium dependent pathways. E3 ligases like Nedd4, SCF complex, APC, GP78 and ITCH are important regulators of calcium mediated processes. A bioinformatics analysis to inspect sequences and interacting partners of 242 candidate E3 ligases show the presence of calcium and/or Calmodulin binding motifs/domains within their sequences. Building a protein-protein interaction (PPI) network of human E3 ligase proteins identifies Ca2+ related proteins as direct interacting partners of E3 ligases. Review of literature, analysis of E3 ligase sequences and their interactome suggests an interconnectivity between calcium signaling and the overall UPS system, especially emphasizing that a subset of E3 ligases have importance in physiological pathways modulated by calcium.
- Published
- 2017
12. Regulation of Mitofusin1 by Mahogunin Ring Finger-1 and the proteasome modulates mitochondrial fusion
- Author
-
Rukmini Mukherjee and Oishee Chakrabarti
- Subjects
0301 basic medicine ,Proteasome Endopeptidase Complex ,Ubiquitin-Protein Ligases ,PINK1 ,Biology ,Mitochondrion ,Mitochondrial Dynamics ,Mitochondrial Membrane Transport Proteins ,GTP Phosphohydrolases ,Mice ,03 medical and health sciences ,Cell Line, Tumor ,Animals ,Humans ,MFN1 ,Molecular Biology ,Neurons ,Ubiquitination ,Cell Biology ,Fibroblasts ,beta Karyopherins ,Mitochondria ,Cell biology ,Ubiquitin ligase ,030104 developmental biology ,Gene Expression Regulation ,Proteasome ,mitochondrial fusion ,Biochemistry ,Proteolysis ,biology.protein ,MUL1 ,Melanocytes ,Mitochondrial fission ,Protein Multimerization ,HeLa Cells ,Signal Transduction - Abstract
Health and homoeostasis are maintained by a dynamic balance between mitochondrial fission and fusion. Mitochondrial fusion machinery is largely unknown in mammals. Only a few reports have illustrated the role of Fzo1 in mitochondrial fusion known in Saccharomyces cerevisiae. We demonstrate that the ubiquitin ligase Mahogunin Ring Finger-1 (MGRN1) interacts with and constitutively ubiquitinates the mammalian homolog, Mitofusin1 (Mfn1) via K63 linkages. In mice models, loss of Mgrn1 function leads to severe developmental defects and adult-onset spongiform neurodegeneration, similar to prion diseases. The tethering of mitochondria to form the ~180kDa Mfn1 complex is independent of MGRN1-mediated ubiquitination. However, successful mitochondrial fusion requires formation of higher oligomers of Mfn1 which in turn needs GTPase activity, intact heptad repeats of Mfn1 and ubiquitination by MGRN1. Following ubiquitination, proteasomal processing of Mfn1 completes the mitochondrial fusion process. This step requires functional p97 activity. These findings suggest a sequence of events where GTPase activity of Mfn1 and tethering of adjacent mitochondria precedes its MGRN1-mediated ubiquitination and proteasomal degradation culminating in mitochondrial fusion.
- Published
- 2016
13. Metamorphosis of Ruthenium-Doped Carbon Dots: In Search of the Origin of Photoluminescence and Beyond
- Author
-
Samita Basu, Amaresh Metya, Debdatto Mookherjee, Rukmini Mukherjee, Asish K. Kundu, Debranjan Mandal, Biswarup Satpati, Pritiranjan Mondal, Abhishek Sau, Kallol Bera, and Oishee Chakrabarti
- Subjects
Photoluminescence ,Materials science ,Dopant ,General Chemical Engineering ,Thermal decomposition ,Doping ,chemistry.chemical_element ,Nanotechnology ,02 engineering and technology ,General Chemistry ,Conjugated system ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Photochemistry ,01 natural sciences ,0104 chemical sciences ,Ruthenium ,chemistry ,Materials Chemistry ,Molecule ,Nanodot ,0210 nano-technology - Abstract
Carbon dots (CDs) are known to have a wide range of applications, yet our understanding of their structures and chemistry remains uncertain because of their highly complex nanostructured framework. Here we attempt to elucidate the molecular structure and intrinsic mechanisms governing photoluminescence (PL) of CDs by trapping seven visibly distinct colored intermediates that evolved during pyrolytic metamorphosis of citric acid with dopant Ru(III). The “excitation-dependent” PL of doped CDs, Ru:CDs, can be tuned by ethylenediamine (EDA), yielding “excitation-independent” highly fluorescent nanodots, Ru:CNDEDAs. To mimic the optical and chemical properties of CDs, we devise a unique model cocktail comprising multiple fluorogenic molecules that truly supports the existence of chemically switchable conjugated moieties in CDs. We propose a plausible molecular level framework of CDs on the basis of spectroscopic findings and existing literature regarding thermal decomposition of CA. The PL of chemically engine...
- Published
- 2016
14. Author response for 'Cytosolic aggregates in presence of nontranslocated proteins perturb endoplasmic reticulum structure and dynamics'
- Author
-
Debdatto Mookherjee, Rukmini Mukherjee, Priyanka Majumder, Subhrangshu Das, Rachid Sougrat, Debmita Chatterjee, Zenia Kaul, Oishee Chakrabarti, and Saikat Chakrabarti
- Subjects
Cytosol ,Chemistry ,Endoplasmic reticulum ,Dynamics (mechanics) ,Biophysics - Published
- 2019
15. Cytosolic aggregates in presence of non-translocated proteins perturb endoplasmic reticulum structure and dynamics
- Author
-
Rachid Sougrat, Priyanka Majumder, Debdatto Mookherjee, Debmita Chatterjee, Subhrangshu Das, Saikat Chakrabarti, Zenia Kaul, Oishee Chakrabarti, and Rukmini Mukherjee
- Subjects
Signal peptide ,Huntingtin ,Nogo Proteins ,Golgi Apparatus ,Chromosomal translocation ,Protein aggregation ,Biology ,Protein Sorting Signals ,Endoplasmic Reticulum ,Biochemistry ,Receptors, Corticotropin-Releasing Hormone ,Prion Proteins ,03 medical and health sciences ,Protein Aggregates ,0302 clinical medicine ,Structural Biology ,Genetics ,Humans ,Protein Precursors ,Molecular Biology ,030304 developmental biology ,0303 health sciences ,Endoplasmic reticulum ,Membrane Proteins ,Cell Biology ,Transmembrane protein ,Cell biology ,Cytosol ,Protein Transport ,Membrane ,030217 neurology & neurosurgery ,HeLa Cells ,Protein Binding - Abstract
Presence of cytosolic protein aggregates and membrane damage are two common attributes of neurodegenerative diseases. These aggregates delay degradation of non-translocated protein precursors leading to their persistence and accumulation in the cytosol. Here, we find that cells with intracellular protein aggregates (of cytosolic prion protein or huntingtin) destabilize the endoplasmic reticulum (ER) morphology and dynamics when non-translocated protein load is high. This affects trafficking of proteins out from the ER, relative distribution of the rough and smooth ER and three-way junctions that are essential for the structural integrity of the membrane network. The changes in ER membranes may be due to high aggregation tendency of the ER structural proteins-reticulons, and altered distribution of those associated with the three-way ER junctions-Lunapark. Reticulon4 is seen to be enriched in the aggregate fractions in presence of non-translocated protein precursors. This could be mitigated by improving signal sequence efficiencies of the proteins targeted to the ER. These were observed using PrP variants and the seven-pass transmembrane protein (CRFR1) with different signal sequences that led to diverse translocation efficiencies. This identifies a previously unappreciated consequence of cytosolic aggregates on non-translocated precursor proteins-their persistent presence affects ER morphology and dynamics. This may be one of the ways in which cytosolic aggregates can affect endomembranes during neurodegenerative disease.
- Published
- 2019
16. Regulation of Phosphoribosyl-Linked Serine Ubiquitination by Deubiquitinases DupA and DupB
- Author
-
Gerhard Hummer, Marcel Heinz, Vladimir V. Rogov, Florian Bonn, Yaobin Liu, Donghyuk Shin, Sagar Bhogaraju, Volker Dötsch, Rukmini Mukherjee, Alexis Gonzalez, Alexandra Stolz, Zhao-Qing Luo, Yan Liu, and Ivan Dikic
- Subjects
Mutant ,Biology ,Endoplasmic Reticulum ,Legionella pneumophila ,Article ,SdeA ,Cell Line ,Deubiquitinating enzyme ,Serine ,03 medical and health sciences ,0302 clinical medicine ,Bacterial Proteins ,Ubiquitin ,Catalytic Domain ,Cell Line, Tumor ,ER-fragmentation ,Humans ,phosphoribosyl serine ubiquitination ,deubiquitination ,Molecular Biology ,030304 developmental biology ,chemistry.chemical_classification ,0303 health sciences ,DNA ligase ,Deubiquitinating Enzymes ,Endoplasmic reticulum ,Ubiquitination ,Cell Biology ,biology.organism_classification ,3. Good health ,Cell biology ,deubiquitinase ,HEK293 Cells ,chemistry ,A549 Cells ,Host-Pathogen Interactions ,Vacuoles ,biology.protein ,Legionnaires' Disease ,phosphodiesterase ,030217 neurology & neurosurgery ,ADP-ribosylation ,HeLa Cells ,Deubiquitination - Abstract
Summary The family of bacterial SidE enzymes catalyzes non-canonical phosphoribosyl-linked (PR) serine ubiquitination and promotes infectivity of Legionella pneumophila. Here, we describe identification of two bacterial effectors that reverse PR ubiquitination and are thus named deubiquitinases for PR ubiquitination (DUPs; DupA and DupB). Structural analyses revealed that DupA and SidE ubiquitin ligases harbor a highly homologous catalytic phosphodiesterase (PDE) domain. However, unlike SidE ubiquitin ligases, DupA displays increased affinity to PR-ubiquitinated substrates, which allows DupA to cleave PR ubiquitin from substrates. Interfering with DupA-ubiquitin binding switches its activity toward SidE-type ligase. Given the high affinity of DupA to PR-ubiquitinated substrates, we exploited a catalytically inactive DupA mutant to trap and identify more than 180 PR-ubiquitinated host proteins in Legionella-infected cells. Proteins involved in endoplasmic reticulum (ER) fragmentation and membrane recruitment to Legionella-containing vacuoles (LCV) emerged as major SidE targets. The global map of PR-ubiquitinated substrates provides critical insights into host-pathogen interactions during Legionella infection., Graphical Abstract, Highlights • Phosphoribosyl serine ubiquitination can be reverted by DupA and DupB • DUP specifically binds to and cleaves PR-ubiquitin from serine on substrates • Catalytically inactive DupA mutants can capture PR-ubiquitinated proteins • PR ubiquitination on multiple ER structural proteins causes ER fragmentation, Shin et al. show that phosphoribosyl serine ubiquitination can be reversed by two deubiquitinases (DupA and DupB) from Legionella. Two DUPs specifically cleave PR-ubiquitin from serine on substrates. Catalytically inactive DupA-based proteomics approach reveals PR-ubiquitinated proteins and their roles in endoplasmic reticulum (ER) remodeling.
- Published
- 2020
17. Mitochondrial Quality Control: Decommissioning Power Plants in Neurodegenerative Diseases
- Author
-
Rukmini Mukherjee and Oishee Chakrabarti
- Subjects
Programmed cell death ,Mitochondrial Turnover ,Cell ,lcsh:Medicine ,Review Article ,Mitochondrion ,Biology ,medicine.disease_cause ,lcsh:Technology ,General Biochemistry, Genetics and Molecular Biology ,Mitochondrial Proteins ,medicine ,Animals ,Humans ,lcsh:Science ,General Environmental Science ,lcsh:T ,Endoplasmic reticulum ,lcsh:R ,Neurodegeneration ,Ubiquitination ,Neurodegenerative Diseases ,General Medicine ,medicine.disease ,Mitochondria ,Cell biology ,Oxidative Stress ,Cytosol ,medicine.anatomical_structure ,Proteolysis ,lcsh:Q ,Oxidative stress - Abstract
The cell has an intricate quality control system to protect its mitochondria from oxidative stress. This surveillance system is multi-tiered and comprises molecules that are present inside the mitochondria, in the cytosol, and in other organelles like the nucleus and endoplasmic reticulum. These molecules cross talk with each other and protect the mitochondria from oxidative stress. Oxidative stress is a fundamental part of early disease pathogenesis of neurodegenerative diseases. These disorders also damage the cellular quality control machinery that protects the cell against oxidative stress. This exacerbates the oxidative damage and causes extensive neuronal cell death that is characteristic of neurodegeneration.
- Published
- 2013
18. Ubiquitin mediated regulation of the E3 ligase GP78 by Mahogunin in trans affects mitochondrial homeostasis
- Author
-
Rukmini Mukherjee and Oishee Chakrabarti
- Subjects
0301 basic medicine ,biology ,Mitochondrial Turnover ,Endoplasmic reticulum ,Neurodegeneration ,Mitochondrial Degradation ,Cell Biology ,Mitochondrion ,medicine.disease ,Ubiquitin ligase ,Cell biology ,03 medical and health sciences ,030104 developmental biology ,Ubiquitin ,Biochemistry ,Mitophagy ,biology.protein ,medicine - Abstract
Cellular quality control provides an efficient surveillance system to regulate mitochondrial turnover. This study elucidates a new interaction between the cytosolic E3 ligase mahogunin RING finger 1 (MGRN1) and the endoplasmic reticulum (ER) ubiquitin E3 ligase GP78 (also known as AMFR). Loss of Mgrn1 function has been implicated in late-onset spongiform neurodegeneration and congenital heart defects, among several developmental defects. Here, we show that MGRN1 ubiquitylates GP78 in trans through non-canonical K11 linkages. This helps maintain constitutively low levels of GP78 in healthy cells, in turn downregulating mitophagy. GP78, however, does not regulate MGRN1. When mitochondria are stressed, cytosolic Ca(2+) increases. This leads to a reduced interaction between MGRN1 and GP78 and its compromised ubiquitylation. Chelating Ca(2+) restores association between the two ligases and the in trans ubiquitylation. Catalytic inactivation of MGRN1 results in elevated levels of GP78 and a consequential increase in the initiation of mitophagy. This is important because functional depletion of MGRN1 by the membrane-associated disease-causing prion protein (Ctm)PrP affects polyubiquitylation and degradation of GP78, also leading to an increase in mitophagy events. This suggests that MGRN1 participates in mitochondrial quality control and could contribute to neurodegeneration in a subset of (Ctm)PrP-mediated prion diseases.
- Published
- 2016
19. Ubiquitin-mediated regulation of the E3 ligase GP78 by MGRN1 in trans affects mitochondrial homeostasis
- Author
-
Rukmini, Mukherjee and Oishee, Chakrabarti
- Subjects
Receptors, Autocrine Motility Factor ,Mice ,Proteasome Endopeptidase Complex ,Ubiquitin ,Ubiquitin-Protein Ligases ,Proteolysis ,Mitophagy ,Ubiquitination ,Animals ,Homeostasis ,Humans ,HeLa Cells ,Mitochondria - Abstract
Cellular quality control provides an efficient surveillance system to regulate mitochondrial turnover. This study elucidates a new interaction between the cytosolic E3 ligase mahogunin RING finger 1 (MGRN1) and the endoplasmic reticulum (ER) ubiquitin E3 ligase GP78 (also known as AMFR). Loss of Mgrn1 function has been implicated in late-onset spongiform neurodegeneration and congenital heart defects, among several developmental defects. Here, we show that MGRN1 ubiquitylates GP78 in trans through non-canonical K11 linkages. This helps maintain constitutively low levels of GP78 in healthy cells, in turn downregulating mitophagy. GP78, however, does not regulate MGRN1. When mitochondria are stressed, cytosolic Ca(2+) increases. This leads to a reduced interaction between MGRN1 and GP78 and its compromised ubiquitylation. Chelating Ca(2+) restores association between the two ligases and the in trans ubiquitylation. Catalytic inactivation of MGRN1 results in elevated levels of GP78 and a consequential increase in the initiation of mitophagy. This is important because functional depletion of MGRN1 by the membrane-associated disease-causing prion protein (Ctm)PrP affects polyubiquitylation and degradation of GP78, also leading to an increase in mitophagy events. This suggests that MGRN1 participates in mitochondrial quality control and could contribute to neurodegeneration in a subset of (Ctm)PrP-mediated prion diseases.
- Published
- 2015
20. Impact of MRT on Peri-Urban Development Case Application of New Garia Terminal Area, Kolkata
- Author
-
Rukmini Mukherjee
- Subjects
Geography ,Terminal (electronics) ,Urban planning ,Peri ,Socioeconomics - Published
- 2014
21. Temporary Architecture as Cultural Heritage: Durga Puja Festival in Kolkata, India
- Author
-
Rukmini Mukherjee
- Subjects
Cultural heritage ,Geography ,Anthropology ,Ancient history ,Architecture - Published
- 2013
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.