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1.
J Cell Sci ; 137(10)2024 May 15.
Article En | MEDLINE | ID: mdl-38770683

Membrane trafficking, a fundamental cellular process encompassing the transport of molecules to specific organelles, endocytosis at the plasma membrane and protein secretion, is crucial for cellular homeostasis and signalling. Cancer cells adapt membrane trafficking to enhance their survival and metabolism, and understanding these adaptations is vital for improving patient responses to therapy and identifying therapeutic targets. In this Review, we provide a concise overview of major membrane trafficking pathways and detail adaptations in these pathways, including COPII-dependent endoplasmic reticulum (ER)-to-Golgi vesicle trafficking, COPI-dependent retrograde Golgi-to-ER trafficking and endocytosis, that have been found in cancer. We explore how these adaptations confer growth advantages or resistance to cell death and conclude by discussing the potential for utilising this knowledge in developing new treatment strategies and overcoming drug resistance for cancer patients.


Carcinogenesis , Cell Membrane , Neoplasms , Humans , Neoplasms/metabolism , Neoplasms/pathology , Carcinogenesis/metabolism , Carcinogenesis/pathology , Animals , Cell Membrane/metabolism , Endoplasmic Reticulum/metabolism , Endocytosis , Protein Transport , Golgi Apparatus/metabolism
2.
Nat Commun ; 15(1): 3978, 2024 May 10.
Article En | MEDLINE | ID: mdl-38729926

A key mechanism employed by plants to adapt to salinity stress involves maintaining ion homeostasis via the actions of ion transporters. While the function of cation transporters in maintaining ion homeostasis in plants has been extensively studied, little is known about the roles of their anion counterparts in this process. Here, we describe a mechanism of salt adaptation in plants. We characterized the chloride channel (CLC) gene AtCLCf, whose expression is regulated by WRKY transcription factor under salt stress in Arabidopsis thaliana. Loss-of-function atclcf seedlings show increased sensitivity to salt, whereas AtCLCf overexpression confers enhanced resistance to salt stress. Salt stress induces the translocation of GFP-AtCLCf fusion protein to the plasma membrane (PM). Blocking AtCLCf translocation using the exocytosis inhibitor brefeldin-A or mutating the small GTPase gene AtRABA1b/BEX5 (RAS GENES FROM RAT BRAINA1b homolog) increases salt sensitivity in plants. Electrophysiology and liposome-based assays confirm the Cl-/H+ antiport function of AtCLCf. Therefore, we have uncovered a mechanism of plant adaptation to salt stress involving the NaCl-induced translocation of AtCLCf to the PM, thus facilitating Cl- removal at the roots, and increasing the plant's salinity tolerance.


Arabidopsis Proteins , Arabidopsis , Cell Membrane , Chloride Channels , Golgi Apparatus , Salt Stress , Arabidopsis/genetics , Arabidopsis/metabolism , Arabidopsis/physiology , Arabidopsis/drug effects , Cell Membrane/metabolism , Arabidopsis Proteins/metabolism , Arabidopsis Proteins/genetics , Golgi Apparatus/metabolism , Chloride Channels/metabolism , Chloride Channels/genetics , Gene Expression Regulation, Plant , Protein Transport/drug effects , Salt Tolerance/genetics , Sodium Chloride/pharmacology , Plants, Genetically Modified
3.
Commun Biol ; 7(1): 596, 2024 May 18.
Article En | MEDLINE | ID: mdl-38762629

Apicomplexan parasites harbor a complex endomembrane system as well as unique secretory organelles. These complex cellular structures require an elaborate vesicle trafficking system, which includes Rab GTPases and their regulators, to assure the biogenesis and secretory of the organelles. Here we exploit the model apicomplexan organism Toxoplasma gondii that encodes a family of Rab GTPase Activating Proteins, TBC (Tre-2/Bub2/Cdc16) domain-containing proteins. Functional profiling of these proteins in tachyzoites reveals that TBC9 is the only essential regulator, which is localized to the endoplasmic reticulum (ER) in T. gondii strains. Detailed analyses demonstrate that TBC9 is required for normal distribution of proteins targeting to the ER, and the Golgi apparatus in the parasite, as well as for the normal formation of daughter inner membrane complexes (IMCs). Pull-down assays show a strong protein interaction between TBC9 and specific Rab GTPases (Rab11A, Rab11B, and Rab2), supporting the role of TBC9 in daughter IMC formation and early vesicular transport. Thus, this study identifies the only essential TBC domain-containing protein TBC9 that regulates early vesicular transport and IMC formation in T. gondii and potentially in closely related protists.


Endoplasmic Reticulum , GTPase-Activating Proteins , Protozoan Proteins , Toxoplasma , rab GTP-Binding Proteins , Toxoplasma/metabolism , Toxoplasma/genetics , Protozoan Proteins/metabolism , Protozoan Proteins/genetics , Endoplasmic Reticulum/metabolism , rab GTP-Binding Proteins/metabolism , rab GTP-Binding Proteins/genetics , GTPase-Activating Proteins/metabolism , GTPase-Activating Proteins/genetics , Golgi Apparatus/metabolism , Protein Transport , Animals , Transport Vesicles/metabolism
4.
Sci Rep ; 14(1): 10160, 2024 05 03.
Article En | MEDLINE | ID: mdl-38698045

How information flow is coordinated for managing transit of 1/3 of the genome through endomembrane pathways by the coat complex II (COPII) system in response to human variation remains an enigma. By examining the interactome of the COPII cage-assembly component Sec13, we show that it is simultaneously associated with multiple protein complexes that facilitate different features of a continuous program of chromatin organization, transcription, translation, trafficking, and degradation steps that are differentially sensitive to Sec13 levels. For the trafficking step, and unlike other COPII components, reduction of Sec13 expression decreased the ubiquitination and degradation of wild-type (WT) and F508del variant cargo protein cystic fibrosis transmembrane conductance regulator (CFTR) leading to a striking increase in fold stability suggesting that the events differentiating export from degradation are critically dependent on COPII cage assembly at the ER Golgi intermediate compartment (ERGIC) associated recycling and degradation step linked to COPI exchange. Given Sec13's multiple roles in protein complex assemblies that change in response to its expression, we suggest that Sec13 serves as an unanticipated master regulator coordinating information flow from the genome to the proteome to facilitate spatial covariant features initiating and maintaining design and function of membrane architecture in response to human variation.


COP-Coated Vesicles , Carrier Proteins , Cystic Fibrosis Transmembrane Conductance Regulator , Protein Transport , Vesicular Transport Proteins , Humans , COP-Coated Vesicles/metabolism , Vesicular Transport Proteins/metabolism , Vesicular Transport Proteins/genetics , Cystic Fibrosis Transmembrane Conductance Regulator/metabolism , Cystic Fibrosis Transmembrane Conductance Regulator/genetics , Golgi Apparatus/metabolism , Endoplasmic Reticulum/metabolism , Ubiquitination , Proteolysis
5.
Mol Cell Biol ; 44(4): 123-137, 2024.
Article En | MEDLINE | ID: mdl-38747374

SREBP transcription factors are central regulators of lipid metabolism. Their proteolytic activation requires ER to the Golgi translocation and subsequent cleavage by site-1-protease (S1P). Produced as a proprotein, S1P undergoes autocatalytic cleavage from its precursor S1PA to mature S1PC form. Here, we report that SPRING (previously C12ORF29) and S1P interact through their ectodomains, and that this facilitates the autocatalytic cleavage of S1PA into its mature S1PC form. Reciprocally, we identified a S1P recognition-motif in SPRING and demonstrate that S1P-mediated cleavage leads to secretion of the SPRING ectodomain in cells, and in liver-specific Spring knockout (LKO) mice transduced with AAV-mSpring. By reconstituting SPRING variants into SPRINGKO cells we show that the SPRING ectodomain supports proteolytic maturation of S1P and SREBP signaling, but that S1P-mediated SPRING cleavage is not essential for these processes. Absence of SPRING modestly diminishes proteolytic maturation of S1PA→C and trafficking of S1PC to the Golgi. However, despite reaching the Golgi in SPRINGKO cells, S1PC fails to rescue SREBP signaling. Remarkably, whereas SREBP signaling was severely attenuated in SPRINGKO cells and LKO mice, that of ATF6, another S1P substrate, was unaffected in these models. Collectively, our study positions SPRING as a dedicated licensing factor for SREBP-specific activation by S1P.


Golgi Apparatus , Mice, Knockout , Proprotein Convertases , Animals , Mice , Golgi Apparatus/metabolism , Humans , Proprotein Convertases/metabolism , Proprotein Convertases/genetics , Serine Endopeptidases/metabolism , Serine Endopeptidases/genetics , Signal Transduction , HEK293 Cells , Liver/metabolism , Proteolysis , Endoplasmic Reticulum/metabolism , Sterol Regulatory Element Binding Proteins/metabolism , Sterol Regulatory Element Binding Proteins/genetics
6.
Sci Adv ; 10(19): eadh0798, 2024 May 10.
Article En | MEDLINE | ID: mdl-38718107

Mutations in the LMNA gene encoding lamins A/C cause an array of tissue-selective diseases, with the heart being the most commonly affected organ. Despite progress in understanding the perturbations emanating from LMNA mutations, an integrative understanding of the pathogenesis underlying cardiac dysfunction remains elusive. Using a novel conditional deletion model capable of translatome profiling, we observed that cardiomyocyte-specific Lmna deletion in adult mice led to rapid cardiomyopathy with pathological remodeling. Before cardiac dysfunction, Lmna-deleted cardiomyocytes displayed nuclear abnormalities, Golgi dilation/fragmentation, and CREB3-mediated stress activation. Translatome profiling identified MED25 activation, a transcriptional cofactor that regulates Golgi stress. Autophagy is disrupted in the hearts of these mice, which can be recapitulated by disrupting the Golgi. Systemic administration of modulators of autophagy or ER stress significantly delayed cardiac dysfunction and prolonged survival. These studies support a hypothesis wherein stress responses emanating from the perinuclear space contribute to the LMNA cardiomyopathy development.


Cardiomyopathies , Lamin Type A , Myocytes, Cardiac , Nuclear Envelope , Animals , Lamin Type A/metabolism , Lamin Type A/genetics , Mice , Nuclear Envelope/metabolism , Cardiomyopathies/metabolism , Cardiomyopathies/etiology , Cardiomyopathies/pathology , Cardiomyopathies/genetics , Myocytes, Cardiac/metabolism , Myocytes, Cardiac/pathology , Autophagy , Stress, Physiological , Disease Models, Animal , Endoplasmic Reticulum Stress , Golgi Apparatus/metabolism , Mice, Knockout
7.
J Cell Biol ; 223(7)2024 Jul 01.
Article En | MEDLINE | ID: mdl-38578286

The AP-1 adaptor complex is found in all eukaryotes, but it has been implicated in different pathways in different organisms. To look directly at AP-1 function, we generated stably transduced HeLa cells coexpressing tagged AP-1 and various tagged membrane proteins. Live cell imaging showed that AP-1 is recruited onto tubular carriers trafficking from the Golgi apparatus to the plasma membrane, as well as onto transferrin-containing early/recycling endosomes. Analysis of single AP-1 vesicles showed that they are a heterogeneous population, which starts to sequester cargo 30 min after exit from the ER. Vesicle capture showed that AP-1 vesicles contain transmembrane proteins found at the TGN and early/recycling endosomes, as well as lysosomal hydrolases, but very little of the anterograde adaptor GGA2. Together, our results support a model in which AP-1 retrieves proteins from post-Golgi compartments back to the TGN, analogous to COPI's role in the early secretory pathway. We propose that this is the function of AP-1 in all eukaryotes.


Golgi Apparatus , Membrane Proteins , Protein Transport , Transcription Factor AP-1 , Humans , Adaptor Proteins, Vesicular Transport/metabolism , Cell Membrane/metabolism , Endosomes/genetics , Endosomes/metabolism , Golgi Apparatus/genetics , Golgi Apparatus/metabolism , HeLa Cells , Membrane Proteins/metabolism , trans-Golgi Network/metabolism , Transcription Factor AP-1/genetics , Transcription Factor AP-1/metabolism
8.
J Cell Biol ; 223(5)2024 May 06.
Article En | MEDLINE | ID: mdl-38558237

The p24 family of proteins have been regarded as cargo receptors for endoplasmic reticulum (ER) to Golgi transport; however, their precise functions have yet to be revealed. In this issue, Pastor-Pareja and colleagues (https://doi.org/10.1083/jcb.202309045) show that the interaction of these proteins with Tango1 is critical for their localization at the ER exit site (ERES) and efficient transport of secretory proteins in Drosophila.


Aryl Hydrocarbon Receptor Nuclear Translocator , Drosophila , Endoplasmic Reticulum , Animals , Aryl Hydrocarbon Receptor Nuclear Translocator/metabolism , COP-Coated Vesicles/metabolism , Drosophila/cytology , Drosophila/metabolism , Endoplasmic Reticulum/metabolism , Golgi Apparatus/metabolism , Protein Transport/physiology , Vesicular Transport Proteins/genetics , Vesicular Transport Proteins/metabolism
9.
Anal Chim Acta ; 1304: 342572, 2024 May 22.
Article En | MEDLINE | ID: mdl-38637042

BACKGROUND: Adenosine 5'-triphosphate (ATP) plays an important role in cell metabolism and has been regarded as an indicator of cell survival and damage. Golgi apparatus participates in the signal transduction processes of substance transport, ion homeostasis and stress when extracellular substances enter cells. Till now, there is no fluorescent probe for monitoring Golgi ATP level fluctuation and visualizing the configuration change of the Golgi apparatus during the inhibition of glycolysis. RESULTS: Herein, we report the synthesis of a novel water-soluble cationic polythiophene derivative (PEMTEA) that can be employed as a fluorescent sensor for measuring ATP in the Golgi apparatus. PEMTEA self-assembles into PT-NP nanoparticles in aqueous solution with a diameter of approximately 2 nm. PT-NP displays high sensitivity and superb selectivity towards ATP with a detection limit of 90 nM and a linear detection range from 0 to 3.0 µM. The nanoparticles show low toxicity to HepG2 cells and good photostability in the Golgi apparatus. With the stimulation of Ca2+, PT-NP was practically applied to real-time monitor of endogenous ATP levels in the Golgi apparatus through fluorescence microscopy. Finally, we studied the relationship between the concentration of ATP and configuration of the Golgi apparatus during the inhibition of glycolysis using PT-NP. SIGNIFICANCE: We have demonstrated that PT-NP can not only indicate the fluctuation and distribution of ATP in the Golgi apparatus, but also give the information of the configuration change of the Golgi apparatus at the single-cell level during the inhibition of glycolysis.


Fluorescent Dyes , Nanoparticles , Fluorescent Dyes/metabolism , Water/metabolism , Golgi Apparatus/metabolism , Adenosine Triphosphate/metabolism , Polymers , Glycolysis
10.
Proc Natl Acad Sci U S A ; 121(15): e2321759121, 2024 Apr 09.
Article En | MEDLINE | ID: mdl-38579009

Adjacent plant cells are connected by specialized cell wall regions, called middle lamellae, which influence critical agricultural characteristics, including fruit ripening and organ abscission. Middle lamellae are enriched in pectin polysaccharides, specifically homogalacturonan (HG). Here, we identify a plant-specific Arabidopsis DUF1068 protein, called NKS1/ELMO4, that is required for middle lamellae integrity and cell adhesion. NKS1 localizes to the Golgi apparatus and loss of NKS1 results in changes to Golgi structure and function. The nks1 mutants also display HG deficient phenotypes, including reduced seedling growth, changes to cell wall composition, and tissue integrity defects. These phenotypes are comparable to qua1 and qua2 mutants, which are defective in HG biosynthesis. Notably, genetic interactions indicate that NKS1 and the QUAs work in a common pathway. Protein interaction analyses and modeling corroborate that they work together in a stable protein complex with other pectin-related proteins. We propose that NKS1 is an integral part of a large pectin synthesis protein complex and that proper function of this complex is important to support Golgi structure and function.


Arabidopsis Proteins , Arabidopsis , Arabidopsis/metabolism , Arabidopsis Proteins/genetics , Arabidopsis Proteins/metabolism , Cell Adhesion/genetics , Pectins/metabolism , Golgi Apparatus/genetics , Golgi Apparatus/metabolism , Cell Wall/metabolism
11.
Cell Mol Biol Lett ; 29(1): 54, 2024 Apr 16.
Article En | MEDLINE | ID: mdl-38627612

BACKGROUND: The trafficking of cargoes from endosomes to the trans-Golgi network requires numerous sequential and coordinated steps. Cargoes are sorted into endosomal-derived carriers that are transported, tethered, and fused to the trans-Golgi network. The tethering step requires several complexes, including the Golgi-associated retrograde protein complex, whose localization at the trans-Golgi network is determined by the activity of small GTPases of the Arl and Rab family. However, how the Golgi-associated retrograde protein complex recognizes the endosome-derived carriers that will fuse with the trans-Golgi network is still unknown. METHODS: We studied the retrograde trafficking to the trans-Golgi network by using fluorescent cargoes in cells overexpressing Rab4b or after Rab4b knocked-down by small interfering RNA in combination with the downregulation of subunits of the Golgi-associated retrograde protein complex. We used immunofluorescence and image processing (Super Resolution Radial Fluctuation and 3D reconstruction) as well as biochemical approaches to characterize the consequences of these interventions on cargo carriers trafficking. RESULTS: We reported that the VPS52 subunit of the Golgi-associated retrograde protein complex is an effector of Rab4b. We found that overexpression of wild type or active Rab4b increased early endosomal to trans-Golgi network retrograde trafficking of the cation-independent mannose-6-phosphate receptor in a Golgi-associated retrograde protein complex-dependent manner. Conversely, overexpression of an inactive Rab4b or Rab4b knockdown attenuated this trafficking. In the absence of Rab4b, the internalized cation-independent mannose 6 phosphate receptor did not have access to VPS52-labeled structures that look like endosomal subdomains and/or endosome-derived carriers, and whose subcellular distribution is Rab4b-independent. Consequently, the cation-independent mannose-6-phosphate receptor was blocked in early endosomes and no longer had access to the trans-Golgi network. CONCLUSION: Our results support that Rab4b, by controlling the sorting of the cation-independent mannose-6-phosphate receptor towards VPS52 microdomains, confers a directional specificity for cargo carriers en route to the trans-Golgi network. Given the importance of the endocytic recycling in cell homeostasis, disruption of the Rab4b/Golgi-associated retrograde protein complex-dependent step could have serious consequences in pathologies.


Receptor, IGF Type 2 , trans-Golgi Network , Cations/metabolism , Endosomes/metabolism , Golgi Apparatus/metabolism , Protein Transport/physiology , Receptor, IGF Type 2/metabolism , trans-Golgi Network/metabolism
12.
Biochim Biophys Acta Gen Subj ; 1868(6): 130617, 2024 Jun.
Article En | MEDLINE | ID: mdl-38614280

BACKGROUND: Sialylation of glycoproteins, including integrins, is crucial in various cancers and diseases such as immune disorders. These modifications significantly impact cellular functions and are associated with cancer progression. Sialylation, catalyzed by specific sialyltransferases (STs), has traditionally been considered to be regulated at the mRNA level. SCOPE OF REVIEW: Recent research has expanded our understanding of sialylation, revealing ST activity changes beyond mRNA level variations. This includes insights into COPI vesicle formation and Golgi apparatus maintenance and identifying specific target proteins of STs that are not predictable through recombinant enzyme assays. MAJOR CONCLUSIONS: This review summarizes that Golgi-associated pathways largely influence the regulation of STs. GOLPH3, GORAB, PI4K, and FAK have become critical elements in sialylation regulation. Some STs have been revealed to possess specificity for specific target proteins, suggesting the presence of additional, enzyme-specific regulatory mechanisms. GENERAL SIGNIFICANCE: This study enhances our understanding of the molecular interplay in sialylation regulation, mainly focusing on the role of integrin and FAK. It proposes a bidirectional system where sialylations might influence integrins and vice versa. The diversity of STs and their specific linkages offer new perspectives in cancer research, potentially broadening our understanding of cellular mechanisms and opening avenues for new therapeutic approaches in targeting sialylation pathways.


Integrins , Polysaccharides , Sialyltransferases , Humans , Integrins/metabolism , Sialyltransferases/metabolism , Polysaccharides/metabolism , Focal Adhesion Protein-Tyrosine Kinases/metabolism , Animals , Golgi Apparatus/metabolism
13.
Toxins (Basel) ; 16(4)2024 Apr 16.
Article En | MEDLINE | ID: mdl-38668619

Cholera toxoid is an established tool for use in cellular tracing in neuroscience and cell biology. We use a sortase labeling approach to generate site-specific N-terminally modified variants of both the A2-B5 heterohexamer and B5 pentamer forms of the toxoid. Both forms of the toxoid are endocytosed by GM1-positive mammalian cells, and while the heterohexameric toxoid was principally localized in the ER, the B5 pentamer showed an unexpectedly specific localization in the medial/trans-Golgi. This study suggests a future role for specifically labeled cholera toxoids in live-cell imaging beyond their current applications in neuronal tracing and labeling of lipid rafts in fixed cells.


Cholera Toxin , Cysteine Endopeptidases , Golgi Apparatus , Humans , Cholera Toxin/metabolism , Cysteine Endopeptidases/metabolism , Golgi Apparatus/metabolism , Animals , Bacterial Proteins/metabolism , Bacterial Proteins/genetics , Aminoacyltransferases/metabolism , Aminoacyltransferases/genetics , Endocytosis
14.
PLoS Pathog ; 20(4): e1012141, 2024 Apr.
Article En | MEDLINE | ID: mdl-38626263

Kaposi's sarcoma-associated herpesvirus (KSHV) is a double-stranded DNA virus etiologically associated with multiple malignancies. Both latency and sporadic lytic reactivation contribute to KSHV-associated malignancies, however, the specific roles of many KSHV lytic gene products in KSHV replication remain elusive. In this study, we report that ablation of ORF55, a late gene encoding a tegument protein, does not impact KSHV lytic reactivation but significantly reduces the production of progeny virions. We found that cysteine 10 and 11 (C10 and C11) of pORF55 are palmitoylated, and the palmytoilation is essential for its Golgi localization and secondary envelope formation. Palmitoylation-defective pORF55 mutants are unstable and undergo proteasomal degradation. Notably, introduction of a putative Golgi localization sequence to these palmitoylation-defective pORF55 mutants restores Golgi localization and fully reinstates KSHV progeny virion production. Together, our study provides new insight into the critical role of pORF55 palmitoylation in KSHV progeny virion production and offers potential therapeutic targets for the treatment of related malignancies.


Golgi Apparatus , Herpesvirus 8, Human , Lipoylation , Viral Proteins , Virion , Virus Replication , Herpesvirus 8, Human/physiology , Herpesvirus 8, Human/metabolism , Golgi Apparatus/metabolism , Golgi Apparatus/virology , Humans , Virion/metabolism , Viral Proteins/metabolism , Viral Proteins/genetics , Virus Replication/physiology , HEK293 Cells
15.
J Cell Sci ; 137(8)2024 Apr 15.
Article En | MEDLINE | ID: mdl-38668719

Clathrin assembles into honeycomb-like lattices at the plasma membrane but also on internal membranes, such as at the Golgi and tubular endosomes. Clathrin assemblies primarily regulate the intracellular trafficking of different cargoes, but clathrin also has non-endocytic functions in cell adhesion through interactions with specific integrins, contributes to intraluminal vesicle formation by forming flat bilayered coats on endosomes and even assembles on kinetochore k-fibers during mitosis. In this Cell Science at a Glance article and the accompanying poster, we review our current knowledge on the different types of canonical and non-canonical membrane-associated clathrin assemblies in mammalian cells, as observed by thin-section or platinum replica electron microscopy in various cell types, and discuss how the structural plasticity of clathrin contributes to its functional diversity.


Clathrin , Animals , Humans , Cell Membrane/metabolism , Clathrin/metabolism , Endosomes/metabolism , Golgi Apparatus/metabolism
16.
Int J Biol Macromol ; 267(Pt 1): 131417, 2024 May.
Article En | MEDLINE | ID: mdl-38582457

Bone morphogenetic protein 15 (BMP15) plays a crucial role in the porcine follicular development. However, its exact functions in the in vitro maturation (IVM) of porcine oocytes remain largely unknown. Here, through cytoplasmic injection of a preassembled crRNA-tracrRNA-Cas9 ribonucleoprotein complex, we achieved BMP15 disruption in approximately 54 % of the cultured porcine oocytes. Editing BMP15 impaired the IVM of porcine oocytes, as indicated by the significantly increased abnormal spindle assembly and reduced first polar body (PB1) extrusion. The editing also impaired cytoplasmic maturation of porcine oocytes, as reflected by reduced abundant of Golgi apparatus and impaired functions of mitochondria. The impaired IVM of porcine oocytes by editing BMP15 possibly was associated with the attenuated SMAD1/5 and EGFR-ERK1/2 signaling in the cumulus granulosa cells (CGCs) and the inhibited MOS/ERK1/2 signaling in oocytes. The attenuated MOS/ERK1/2 signaling may contribute to the inactivation of maturation promoting factor (MPF) and the increased abnormal spindle assembly, leading to reduced PB1 extrusion. It also may contribute to reduced Golgi apparatus formation, and impaired functions of mitochondria. These findings expand our understanding of the regulatory role of BMP15 in the IVM of porcine oocytes and provide a basis for manipulation of porcine reproductive performance.


Bone Morphogenetic Protein 15 , Oocytes , Spindle Apparatus , Animals , Oocytes/metabolism , Bone Morphogenetic Protein 15/genetics , Bone Morphogenetic Protein 15/metabolism , Swine , Female , Spindle Apparatus/metabolism , MAP Kinase Signaling System , Mitochondria/metabolism , In Vitro Oocyte Maturation Techniques , Golgi Apparatus/metabolism , Organelles/metabolism , Organelles/genetics , Signal Transduction
17.
Int J Mol Sci ; 25(8)2024 Apr 20.
Article En | MEDLINE | ID: mdl-38674111

Coatomer Protein Complex-II (COPII) mediates anterograde vesicle transport from the endoplasmic reticulum (ER) to the Golgi apparatus. Here, we report that the COPII coatomer complex is constructed dependent on a small GTPase, Sar1, in spermatocytes before and during Drosophila male meiosis. COPII-containing foci co-localized with transitional endoplasmic reticulum (tER)-Golgi units. They showed dynamic distribution along astral microtubules and accumulated around the spindle pole, but they were not localized on the cleavage furrow (CF) sites. The depletion of the four COPII coatomer subunits, Sec16, or Sar1 that regulate COPII assembly resulted in multinucleated cell production after meiosis, suggesting that cytokinesis failed in both or either of the meiotic divisions. Although contractile actomyosin and anilloseptin rings were formed once plasma membrane ingression was initiated, they were frequently removed from the plasma membrane during furrowing. We explored the factors conveyed toward the CF sites in the membrane via COPII-mediated vesicles. DE-cadherin-containing vesicles were formed depending on Sar1 and were accumulated in the cleavage sites. Furthermore, COPII depletion inhibited de novo plasma membrane insertion. These findings suggest that COPII vesicles supply the factors essential for the anchoring and/or constriction of the contractile rings at cleavage sites during male meiosis in Drosophila.


COP-Coated Vesicles , Cytokinesis , Drosophila Proteins , Meiosis , Vesicular Transport Proteins , Animals , Male , Cadherins/metabolism , Cell Membrane/metabolism , COP-Coated Vesicles/metabolism , Cytokinesis/physiology , Drosophila/metabolism , Drosophila melanogaster/metabolism , Drosophila Proteins/metabolism , Drosophila Proteins/genetics , Endoplasmic Reticulum/metabolism , Golgi Apparatus/metabolism , Meiosis/physiology , Monomeric GTP-Binding Proteins/metabolism , Monomeric GTP-Binding Proteins/genetics , Spermatocytes/metabolism , Vesicular Transport Proteins/genetics , Vesicular Transport Proteins/metabolism
18.
Mol Microbiol ; 121(5): 1063-1078, 2024 May.
Article En | MEDLINE | ID: mdl-38558112

Metalloprotease-gp63 is a virulence factor secreted by Leishmania. However, secretory pathway in Leishmania is not well defined. Here, we cloned and expressed the GRASP homolog from Leishmania. We found that Leishmania expresses one GRASP homolog of 58 kDa protein (LdGRASP) which localizes in LdRab1- and LPG2-positive Golgi compartment in Leishmania. LdGRASP was found to bind with COPII complex, LdARF1, LdRab1 and LdRab11 indicating its role in ER and Golgi transport in Leishmania. To determine the function of LdGRASP, we generated LdGRASP knockout parasites using CRISPR-Cas9. We found fragmentation of Golgi in Ld:GRASPKO parasites. Our results showed enhanced transport of non-GPI-anchored gp63 to the cell surface leading to higher secretion of this form of gp63 in Ld:GRASPKO parasites in comparison to Ld:WT cells. In contrast, we found that transport of GPI-anchored gp63 to the cell surface is blocked in Ld:GRASPKO parasites and thereby inhibits its secretion. The overexpression of dominant-negative mutant of LdRab1 or LdSar1 in Ld:GRASPKO parasites significantly blocked the secretion of non-GPI-anchored gp63. Interestingly, we found that survival of transgenic parasites overexpressing Ld:GRASP-GFP is significantly compromised in macrophages in comparison to Ld:WT and Ld:GRASPKO parasites. These results demonstrated that LdGRASP differentially regulates Ldgp63 secretory pathway in Leishmania.


Metalloendopeptidases , Protozoan Proteins , Virulence Factors , Virulence Factors/metabolism , Virulence Factors/genetics , Protozoan Proteins/metabolism , Protozoan Proteins/genetics , Metalloendopeptidases/metabolism , Metalloendopeptidases/genetics , Golgi Apparatus/metabolism , Endoplasmic Reticulum/metabolism , Macrophages/parasitology , Macrophages/metabolism , Animals , Leishmania/metabolism , Leishmania/genetics , Protein Transport , CRISPR-Cas Systems , Golgi Matrix Proteins/metabolism , Golgi Matrix Proteins/genetics
19.
Proc Natl Acad Sci U S A ; 121(18): e2318619121, 2024 Apr 30.
Article En | MEDLINE | ID: mdl-38657050

Nonalcoholic fatty liver disease, recently renamed metabolic dysfunction-associated steatotic liver disease (MASLD), is a progressive metabolic disorder that begins with aberrant triglyceride accumulation in the liver and can lead to cirrhosis and cancer. A common variant in the gene PNPLA3, encoding the protein PNPLA3-I148M, is the strongest known genetic risk factor for MASLD. Despite its discovery 20 y ago, the function of PNPLA3, and now the role of PNPLA3-I148M, remain unclear. In this study, we sought to dissect the biogenesis of PNPLA3 and PNPLA3-I148M and characterize changes induced by endogenous expression of the disease-causing variant. Contrary to bioinformatic predictions and prior studies with overexpressed proteins, we demonstrate here that PNPLA3 and PNPLA3-I148M are not endoplasmic reticulum-resident transmembrane proteins. To identify their intracellular associations, we generated a paired set of isogenic human hepatoma cells expressing PNPLA3 and PNPLA3-I148M at endogenous levels. Both proteins were enriched in lipid droplet, Golgi, and endosomal fractions. Purified PNPLA3 and PNPLA3-I148M proteins associated with phosphoinositides commonly found in these compartments. Despite a similar fractionation pattern as the wild-type variant, PNPLA3-I148M induced morphological changes in the Golgi apparatus, including increased lipid droplet-Golgi contact sites, which were also observed in I148M-expressing primary human patient hepatocytes. In addition to lipid droplet accumulation, PNPLA3-I148M expression caused significant proteomic and transcriptomic changes that resembled all stages of liver disease. Cumulatively, we validate an endogenous human cellular system for investigating PNPLA3-I148M biology and identify the Golgi apparatus as a central hub of PNPLA3-I148M-driven cellular change.


Acyltransferases , Golgi Apparatus , Lipid Droplets , Phospholipases A2, Calcium-Independent , Humans , Acyltransferases/metabolism , Golgi Apparatus/metabolism , Lipase/metabolism , Lipase/genetics , Lipid Droplets/metabolism , Membrane Proteins/metabolism , Membrane Proteins/genetics , Non-alcoholic Fatty Liver Disease/genetics , Non-alcoholic Fatty Liver Disease/metabolism , Non-alcoholic Fatty Liver Disease/pathology , Phospholipases A2, Calcium-Independent/metabolism
20.
Int Immunopharmacol ; 133: 112103, 2024 May 30.
Article En | MEDLINE | ID: mdl-38648713

BACKGROUND: Sepsis is often accompanied by multiple organ dysfunction, in which the incidence of cardiac injury is about 60%, and is closely related to high mortality. Recent studies have shown that Golgi stress is involved in liver injury, kidney injury, and lung injury in sepsis. However, whether it is one of the key mechanisms of sepsis-induced cardiomyopathy (SIC) is still unclear. The aim of this study is to investigate whether Golgi stress mediates SIC and the specific mechanism. METHODS: Sepsis model of male C57BL/6J mice was established by cecal ligation and puncture. To observe the effect of Golgi stress on SIC, mice were injected with Golgi stimulant (Brefeldin A) or Golgi inhibitor (Glutathione), respectively. The 7-day survival rate of mice were recorded, and myocardial injury indicators including cardiac function, myocardial enzymes, myocardial pathological tissue score, myocardial inflammatory factors, and apoptosis were detected. The morphology of Golgi was observed by immunofluorescence, and the Golgi stress indices including GM-130, GOLPH3 and Goligin97 were detected by WB and qPCR. RESULTS: After CLP, the cardiac function of mice was impaired and the levels of myocardial enzymes were significantly increased. Golgi stress was accompanied by increased myocardial inflammation and apoptosis. Moreover, the expressions of morphological proteins GM-130 and Golgin97 were decreased, and the expression of stress protein GOLPH3 was increased. In addition, Brefeldin A increased 7-day mortality and the above indicators in mice. The use of glutathione improves all of the above indicators. CONCLUSION: Golgi stress mediates SIC, and the inhibition of Golgi stress can improve SIC by inhibiting apoptosis and inflammation.


Apoptosis , Brefeldin A , Cardiomyopathies , Golgi Apparatus , Mice, Inbred C57BL , Sepsis , Animals , Apoptosis/drug effects , Male , Sepsis/complications , Sepsis/drug therapy , Golgi Apparatus/metabolism , Golgi Apparatus/drug effects , Cardiomyopathies/etiology , Cardiomyopathies/drug therapy , Mice , Brefeldin A/pharmacology , Inflammation/drug therapy , Disease Models, Animal , Glutathione/metabolism , Myocardium/pathology , Myocardium/metabolism , Membrane Proteins/metabolism , Membrane Proteins/genetics , Humans
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