Regulation Of Trafficking Research Articles

Control and Regulation of Human Trafficking in Nigeria: A Legal Framework Analysis

Human trafficking is a pervasive and complex issue affecting millions worldwide. Despite international efforts to combat trafficking, the scourge persists, necessitating a critical examination of the existing legal framework as it relates to Nigeria. This article undertakes a study of Nigeria's legal framework and the various measures adopted by the Nigerian government to curb the menace of human trafficking, with a view to identifying best practices and areas for improvement. This article employs the analytical approach to Nigeria's Trafficking in Persons (Prohibition) Enforcement and Administration Act 2015. The article examines the definition of trafficking, the prosecution and punishment of offenders, the protection of victims, and prevention strategies employed by the Nigerian government. The findings reveal that while Nigeria has made significant strides in combating human trafficking, there are still gaps to be filled with respect to penalties for offenders. Nigeria's legislation, although well-intentioned, is often criticized for its limited scope and inadequate enforcement mechanisms. This article contributes to the existing literature on human trafficking by providing a nuanced understanding of the control measures employed in Nigeria. The article highlights the need for a more coordinated and effective approach to combating human trafficking, emphasizing the importance of international cooperation, capacity building, and community engagement. Ultimately, this article aims to inform policy and legislative reforms, promoting a more robust response to the scourge of human trafficking

Neutrophils restricted contribution of CCRL2 genetic variants to COVID-19 severity.

The 3p21.31 locus is the most robust genomic region associated with COVID-19 severity. This locus contains a main chemokine receptor (CKR) cluster. We tested expression quantitative trait loci (eQTL) targeting the 3p21.31 CKR cluster linked to COVID-19 hospitalization in Europeans from the COVID-19 HGI meta-analysis. Among these, CCRL2, a key regulator of neutrophil trafficking, was targeted by neutrophil-restricted eQTLs. We confirmed these eQTLs in an Italian COVID-19 cohort. Haplotype analysis revealed a link between an increased CCRL2 expression and COVID-19 severity and hospitalization. By the exposure of neutrophils to a TLR8 ligand, reflecting a viral infection, we revealed specific chromatin domains within the 3p21.31 locus exclusive to neutrophils. In addition, the identified variants mapped within these regions altered the binding motif of neutrophils-expressed transcription factors. These results support that CCRL2 eQTL variants contribute to the risk of severe COVID-19 by selectively affecting neutrophil functions.

TAT-1, a phosphatidylserine flippase, affects molting and regulates membrane trafficking in the epidermis of C. elegans.

Membrane trafficking is a conserved process required for import, export, movement, and distribution of proteins and other macromolecules within cells. The Caenorhabditis elegans NIMA-related kinases NEKL-2 (human NEK8/9) and NEKL-3 (human NEK6/7) are conserved regulators of membrane trafficking and are required for the completion of molting. Using a genetic approach we identified reduction-of-function mutations in tat-1 that suppress nekl-associated molting defects. tat-1 encodes the C. elegans ortholog of mammalian ATP8A1/2, a phosphatidylserine (PS) flippase that promotes the asymmetric distribution of PS on the cytosolic leaflet of lipid membrane bilayers. CHAT-1 (human CDC50), a conserved chaperone, was required for the correct localization of TAT-1, and chat-1 inhibition strongly suppressed nekl defects. Using a PS sensor, we found that TAT-1 was required for the normal localization of PS at apical endosomes and that loss of TAT-1 led to aberrant endosomal morphologies. Consistent with these data, TAT-1 localized to early endosomes and to recycling endosomes marked with RME-1, the C. elegans ortholog of the human EPS15 homology (EH) domain-containing protein, EHD1. TAT-1, PS biosynthesis, and the PS-binding protein RFIP-2 (human RAB11-FIP2) were all required for the normal localization of RME-1 to apical endosomes. Consistent with these proteins functioning together, inhibition of RFIP-2 or RME-1 led to the partial suppression of nekl molting defects, as did inhibition of PS biosynthesis. We propose that TAT-1 flippase activity, in conjunction with RFIP-2, promotes the recruitment of RME-1 to apical recycling endosomes and that inhibition of TAT-1-RFIP-2-RME-1 can compensate for a reduction in NEKL activities.

Age-associated accumulation of RAB9 disrupts oocyte meiosis.

The critical role of some RAB family members in oocyte meiosis has been extensively studied, but their role in oocyte aging remains poorly understood. Here, we report that the vesicle trafficking regulator, RAB9 GTPase, is essential for oocyte meiosis and aging in humans and mice. RAB9 was mainly located at the meiotic spindle periphery and cortex during oocyte meiosis. In humans and mice, we found that the RAB9 protein level were significantly increased in old oocytes. Age-related accumulation of RAB9 inhibits first polar body extrusion and reduces the developmental potential of oocytes. Further studies showed that increased Rab9 disrupts spindle formation and chromosome alignment. In addition, Rab9 overexpression disrupts the actin cap formation and reduces the cortical actin levels. Mechanically, Rab9-OE increases ROS levels, decreases mitochondrial membrane potential, ATP content and the mtDNA/nDNA ratio. Further studies showed that Rab9-OE activates the PINK1-PARKIN mitophagy pathway. Importantly, we found that reducing RAB9 protein expression in old oocytes could partially improve the rate of old oocyte maturation, ameliorate the accumulation of age-related ROS levels and spindle abnormalities, and partially rescue ATP levels, mtDNA/nDNA ratio, and PINK1 and PARKIN expression. In conclusion, our results suggest that RAB9 is required to maintain the balance between mitochondrial function and meiosis, and that reducing RAB9 expression is a potential strategy to ameliorate age-related deterioration of oocyte quality.

An RNAi screen of Rab GTPase genes in C. elegans reveals that somatic cells of the reproductive system depend on rab-1 for morphogenesis but not stem cell niche maintenance.

Membrane trafficking is a crucial function of all cells and is regulated at multiple levels from vesicle formation, packaging, and localization to fusion, exocytosis, and endocytosis. Rab GTPase proteins are core regulators of eukaryotic membrane trafficking, but developmental roles of specific Rab GTPases are less well characterized, potentially because of their essentiality for basic cellular function. C. elegans gonad development entails the coordination of cell growth, proliferation, and migration-processes in which membrane trafficking is known to be required. Here we take an organ-focused approach to Rab GTPase function in vivo to assess the roles of Rab genes in reproductive system development. We performed a whole-body RNAi screen of the entire Rab family in C. elegans to uncover Rabs essential for gonad development. Notable gonad defects resulted from RNAi knockdown of rab-1, the key regulator of ER-Golgi trafficking. We then examined the effects of tissue-specific RNAi knockdown of rab-1 in somatic reproductive system and germline cells. We interrogated the dual functions of the distal tip cell (DTC) as both a leader cell of gonad organogenesis and the germline stem cell niche. We find that rab-1 functions cell-autonomously and non-cell-autonomously to regulate both somatic gonad and germline development. Gonad migration, elongation, and gamete differentiation-but surprisingly not germline stem niche function-are highly sensitive to rab-1 RNAi.

Lipid Droplet Accumulation in Cancer: Targeting Lipophagy as a Therapeutic Strategy

Lipid droplets (LDs) are dynamic organelles involved in cellular lipid storage, trafficking, and metabolic regulation. Recent studies highlight their altered accumulation in various cancer types, correlating with tumorigenesis, progression, and metastasis. The accumulation of LDs in cancer cells contributes to oncogenic lipid metabolism, which promotes cell proliferation, resistance to apoptosis, and adaptation to tumor microenvironment stresses, including hypoxia and nutrient deprivation. Lipophagy, a specialized form of autophagy responsible for the selective degradation of LDs, has emerged as a potential target for cancer therapy due to its role in modulating cellular lipid reserves and maintaining energy balance. This review explores the molecular mechanisms underlying LD accumulation in cancer and the regulation of lipophagy, examining the implications of lipid storage modulation on cancer cell survival and metabolic adaptation. We also discuss therapeutic strategies aimed at targeting lipophagy pathways, such as inhibition of key lipophagic regulators and combination approaches with established chemotherapies, to improve cancer treatment efficacy. Understanding the intersection of lipid metabolism, LD biogenesis, and lipophagy may offer novel therapeutic avenues, providing more personalized and effective interventions for lipid-metabolism-driven cancers. Keywords: Lipid droplets; Lipophagy; Cancer metabolism; Autophagy; Lipid metabolism; Therapeutic targets in cancer; Lipid accumulation in tumors

Classification and functional characterization of regulators of intracellular STING trafficking identified by genome-wide optical pooled screening.

Stimulator of interferon genes (STING) traffics across intracellular compartments to trigger innate responses. Mutations in factors regulating this process lead to inflammatory disorders. To systematically identify factors involved in STING trafficking, we performed a genome-wide optical pooled screen (OPS). Based on the subcellular localization of STING in 45 million cells, we defined 464 clusters of gene perturbations based on their cellular phenotypes. A secondary, higher-dimensional OPS identified 73 finer clusters. We show that the loss of the gene of unknown function C19orf25, which clustered with USE1, a protein involved in Golgi-to-endoplasmic reticulum (ER) transport, enhances STING signaling. Additionally, HOPS deficiency delayed STING degradation and consequently increased signaling. Similarly, GARP/RIC1-RGP1 loss increased STING signaling by delaying STING Golgi exit. Our findings demonstrate that genome-wide genotype-phenotype maps based on high-content cell imaging outperform other screening approaches and provide a community resource for mining factors that impact STING trafficking and other cellular processes.

Hijacking host cell vesicular transport: New insights into the nutrient acquisition mechanism of Chlamydia.

Chlamydia infection is an important cause of public health diseases, and no effective vaccine is currently available. Owing to its unique intracellular lifestyle, Chlamydia requires a variety of nutrients and substrates from host cells, particularly sphingomyelin, cholesterol, iron, amino acids, and the mannose-6-phosphate receptor, which are essential for inclusion development. Here, we summarize the recent advances in Chlamydia nutrient acquisition mechanism by hijacking host cell vesicular transport, which plays an important role in chlamydial growth and development. Chlamydia obtains the components necessary to complete its intracellular developmental cycle by recruiting Rab proteins (major vesicular trafficking regulators) and Rab effector proteins to the inclusion, interfering with Rab-mediated multivesicular trafficking, reorienting the nutrition of host cells, and reconstructing the intracellular niche environment. Consequently, exploring the role of vesicular transport in nutrient acquisition offers a novel perspective on new approaches for preventing and treating Chlamydia infection.

Disruption of Iqsec1 in mice leads to embryonic lethality with reduced large apical vacuoles in the visceral endoderm.

Iqsec1 (IQ motif and Sec7 domain-containing protein 1), also known as BRAG2 (Brefeldin A-resistant Arf-GEF 2), is a guanine nucleotide exchange factor that regulates membrane trafficking, cytoskeletal organization, and signal transduction by activating class II and III ADP-ribosylation factors. To investigate the physiological role of Iqsec1 at the whole animal level, we generated Iqsec1-deficient mice using CRISPR/Cas9-mediated gene editing. Nearly all Iqsec1-/- mice (99%) exhibited embryonic lethality with severe growth retardation. Electron microscopy revealed that Iqsec1-/- embryos at embryonic day 8.5 lacked large apical vacuoles in visceral endoderm cells of the yolk sac, compared with controls. These findings suggest that Iqsec1 plays a critical role in embryogenesis, likely through regulation of membrane trafficking in visceral endoderm cells.

Pharmacokinetics and Pharmacodynamics of Rusfertide, a Hepcidin Mimetic, Following Subcutaneous Administration of a Lyophilized Powder Formulation in Healthy Volunteers.

Hepcidin, an endogenous peptide hormone, binds to ferroportin and is the master regulator of iron trafficking. Rusfertide, a synthetic peptide, is a potent hepcidin mimetic. Clinical studies suggest rusfertide may be effective in the treatment of polycythemia vera. This study investigated the dose-ranging pharmacokinetics, pharmacodynamics, and safety of a lyophilized formulation of rusfertide. A randomized open-label crossover study was conducted in two groups of healthy adult subjects to evaluate the safety, tolerability, pharmacokinetics, and pharmacodynamics of subcutaneous rusfertide doses that ranged from 10 to 60 mg of a lyophilized formulation and 20 mg of an aqueous prefilled syringe formulation that were used in clinical trials. Rusfertide showed a rapid initial absorption. Median time to peak plasma concentrations for the lyophilized formulation was 24h for doses of 10-30 mg and 2-4 h for doses of 45 and 60 mg. Mean terminal half-life ranged from 19.6 to 57.1 h. Rusfertide peak concentration and area under the concentration-time curve increased with an increasing dose, but in a less than dose-proportional manner. Metabolites M4 and M9 were identified as major metabolites. At the rusfertide 20-mg dose, the lyophilized formulation had an area under the concentration-time curve from time zero to infinity approximately 1.5-fold higher than the aqueous formulation. The elimination half-life was comparable for the two formulations. Dose-related decreases in serum iron and transferrin-iron saturation were seen following rusfertide treatment. The majority of treatment-emergent adverse events were mild; treatment-related treatment-emergent adverse events seen in ≥10% of subjects were injection-site erythema and injection-site pruritus. Rusfertide was well tolerated; the pharmacokinetic and pharmacodynamic results indicate that lyophilized rusfertide is suitable for once-weekly or twice-weekly administration.

Single-cell RNA-sequencing of human spleens reveals an IDO-1+ tolerogenic dendritic cell subset in pancreatic cancer patients that is absent in normal individuals

Local and systemic immunosuppression are prominent features of pancreatic cancer, rendering anti-tumor effector cells inactive and immunotherapeutic approaches ineffective. The spleen, an understudied point of antigen-presentation and T cell priming in humans, holds particular importance in pancreatic cancer due to its proximity to the developing tumor. As main effectors of antigen presentation, dendritic cells display antigens to lymphocytes, thereby bridging the innate and adaptive immune response. While tumor-infiltrating anti-inflammatory dendritic cells have been described, splenic dendritic cells have historically just been considered to stimulate the anti-tumor immune response. Here, we describe, for the first time, the presence of an immunosuppressive, tolerogenic IDO1+ dendritic cell subset in the spleens of pancreatic cancer patients that likely contributes to systemic immunosuppression that is associated with pancreatic ductal adenocarcinoma. Network analysis of scRNA seq data reveals extensive communication networks between the identified tolerogenic DC cluster and numerous immune cell populations in the spleen. Interactions with innate and adaptive immune cells suggest a broad influence on leukocyte trafficking and immune regulation within the spleen microenvironment. The identification of signaling pathways involving AHR and IDO-1, CCL19, NECTIN2, CLEC2D, and others elucidates potential mechanisms underlying the immunosuppressive functions of this cell type.

New insights into the mechanisms of red blood cell enucleation: From basics to clinical applications.

Red blood cell (RBC) enucleation is a crucial step in the process of erythropoiesis. By removing the nucleus, RBCs gain greater flexibility, enabling them to traverse narrow capillaries with ease, thereby enhancing the efficiency of oxygen and carbon dioxide transport. This transformation underscores the intricate balance between cellular structure and function essential for maintaining homeostasis. This review delves into the multifaceted enucleation process, outlining its complex steps that encompass protein sorting, vesicle trafficking, cytoskeletal remodeling, and apoptosis regulation, while also exploring the potential of enhancing the enucleation rate of RBCs in vitro. We emphasize the intricate regulation of this process, which is orchestrated by multiple factors. This includes transcription factors that meticulously guide protein synthesis and sorting through the modulation of gene expression, as well as non-coding RNAs that play a pivotal role in post-transcriptional regulation during various stages of RBC enucleation. Additionally, macrophages participate in the enucleation process by engulfing and clearing the extruded nuclei, further ensuring the proper development of RBCs. Although many studies have deeply explored the molecular mechanisms of enucleation, the roles of apoptosis and anti-apoptotic processes in RBC enucleation remain incompletely understood. In this review, we aim to comprehensively summarize the RBC enucleation process and explore the progress made in ex vivo RBC generation. In the future, a deeper understanding of the enucleation process could provide significant benefits to patients suffering from anemia and other related conditions.

Evaluation of Suppressor of Cytokine Signaling 1, Interleukin-29 and Lysosomal Trafficking Regulator in Severe COVID-19

Background: The pathogenesis of Severe SARS-CoV-2 is closely linked to severe immune responses and inflammation caused by the SARS-CoV-2 virus. In this context, the suppressor of cytokine signaling 1 (SOCS1) has a crucial role in inhibiting cytokine-induced immune responses. On the other hand, interleukin-29 (IL-29) and lysosomal trafficking regulator (LYST) are important molecules involved in inducing immune responses. Objectives: This study aimed to assess the mRNA levels of SOCS1, IL-29, and LYST in the SARS-CoV-2-infected patients with severe symptoms. Methods: In this cross-sectional study, 70 SARS-CoV-2 infected patients with severe symptoms and 70 healthy controls were evaluated. RNA was extracted from peripheral blood and after cDNA synthesis, the mRNA levels of SOCS1, IL-29, and LYST were assessed by Real-Time PCR technique Results: The study revealed that severe COVID-19 patients exhibited a significant increase in mRNA levels of IL-29 compared to healthy individuals. However, there were no observed alterations in the mRNA levels of SOCS1 and LYST in the patient group. Conclusions: The results emphasize the importance of IL-29 as a potential biomarker or therapeutic target for severe COVID-19 cases. Further research is needed to investigate the specific mechanisms through which IL-29 influences immune responses and contributes to the development of severe disease. Additionally, exploring other factors that may regulate SOCS1 and LYST expression could provide a more comprehensive understanding of their roles in COVID-19 pathogenesis.

A unique symbiosome in an anaerobic single-celled eukaryote

Symbiotic relationships between eukaryotes and prokaryotes played pivotal roles in the evolution of life and drove the emergence of specialized symbiotic structures in animals, plants and fungi. The host-evolved symbiotic structures of microbial eukaryotes – the vast majority of such hosts in nature – remain largely unstudied. Here we describe highly structured symbiosomes within three free-living anaerobic protists (Anaeramoeba spp.). We dissect this symbiosis using complete genome sequencing and transcriptomics of host and symbiont cells coupled with fluorescence in situ hybridization, and 3D reconstruction using focused-ion-beam scanning electron microscopy. The emergence of the symbiosome is underpinned by expansion of gene families encoding regulators of membrane trafficking and phagosomal maturation and extensive bacteria-to-eukaryote lateral transfer. The symbionts reside deep within a symbiosomal membrane network that enables metabolic syntrophy by precisely positioning sulfate-reducing bacteria alongside host hydrogenosomes. Importantly, the symbionts maintain connections to the Anaeramoeba plasma membrane, blurring traditional boundaries between ecto- and endosymbiosis.

Rab2A-mediated Golgi-lipid droplet interactions support very-low-density lipoprotein secretion in hepatocytes

Lipid droplets (LDs) serve as crucial hubs for lipid trafficking and metabolic regulation through their numerous interactions with various organelles. While the interplay between LDs and the Golgi apparatus has been recognized, their roles and underlying mechanisms remain poorly understood. Here, we reveal the role of Ras-related protein Rab-2A (Rab2A) in mediating LD-Golgi interactions, thereby contributing to very-low-density lipoprotein (VLDL) lipidation and secretion in hepatocytes. Mechanistically, our findings identify a selective interaction between Golgi-localized Rab2A and 17-beta-hydroxysteroid dehydrogenase 13 (HSD17B13) protein residing on LDs. This complex facilitates dynamic organelle communication between the Golgi apparatus and LDs, thus contributing to lipid transfer from LDs to the Golgi apparatus for VLDL2 lipidation and secretion. Attenuation of Rab2A activity via AMP-activated protein kinase (AMPK) suppresses the Rab2A-HSD17B13 complex formation, impairing LD-Golgi interactions and subsequent VLDL secretion. Furthermore, genetic inhibition of Rab2A and HSD17B13 in the liver reduces the serum triglyceride and cholesterol levels. Collectively, this study provides a new perspective on the interactions between the Golgi apparatus and LDs.

NADPH oxidases regulation of vesicular trafficking during zebrafish epiboly.

NADPH oxidases regulation of vesicular trafficking during zebrafish epiboly.

Dysfunctional atrial fibroblast processing of filamin A in atrial fibrillation

Abstract Background/Introduction Atrial fibrillation (AF), the most common sustained cardiac arrhythmia, is associated with atrial structural remodelling, hallmarked by fibrosis. Atrial fibrosis is instigated by atrial fibroblasts (AFBs). It was previously uncovered the hormone calcitonin (CT) is produced in the heart and, via binding to the CT-receptors (CTR), inhibits atrial fibrogenesis and fibroblast profibrotic activity. [1] In AF, abnormally increased CTR internalisation causes loss of physiological surface CTR and prevents fibroblast activation by CT. The molecular mechanisms of this phenomenon in ACFs are unknown. Aim To explore the role of filamin A (FLNa), an actin cross-linking protein that was previously shown to interact with CTR, [2] in the regulation of CTR trafficking. Methods AFBs were enzymatically isolated from left atrial appendage biopsies collected from 30 patients in persistent AF or normal sinus rhythm (SR, controls) undergoing elective heart surgery. Immunostaining assessed the localisation of CTR and its overlap with the nucleus (stained with DAPI) and FLNa in AFBs. Co-localisation was quantified by the JACoP BIOP plugin for ImageJ. Target mRNA expression was assessed by RT-qPCR and protein levels by immunoblot. Immunoprecipitation (IP) then immunoblot (IB) validated protein-protein interactions. Calpain activity was assessed with a fluorescence-based assay. The effects of calpains on FLNa proteolytic processing was examined with calpain inhibitor calpeptin (10nM–100nM vs DMSO loading control). Results Immunostaining revealed aberrant, intracellular localisation of CTR in AF-AFBs (A) with increased nuclear localisation (p=0.03) and reduced co-localisation with FLNa (p=0.03). FLNa gene expression showed a trend towards reduction in AF (by 36%, p=0.06; B). Meanwhile, although full-length FLNa protein was unaltered in AF, there was a striking 67% reduction (p=0.02) in the expression of FLNa’s c-terminal fragment (FLNaCT), which contains the CTR binding domain (C). Co-immunoprecipitation confirmed a physical interaction between CTR and FLNaCT (D) in both SR and AF AFBs. FLNaCT is typically generated when FLNa is cleaved by the protease calpain 1, whose protein (F) but not mRNA (E), was significantly downregulated (71%, p<0.001) in AF. Puzzlingly, a ~70% loss of calpain 1 protein was associated with unchanged calpain activity (G) and FLNaCT levels in AFBs treated with calpain inhibitor calpeptin (H). Conclusions Persistent AF is associated with an aberrant CTR localisation and FLNa proteolytic processing, not attributable to altered calpain activity. Further characterisation of the molecular determinants of the altered CTR localisation may uncover novel and potentially druggable facets of structural remodelling in AF.

Recent Advances in Ubiquitin Signals Regulating Plant Membrane Trafficking.

Ubiquitination is a reversible post-translational modification involving the attachment of ubiquitin, a 76-amino acid protein conserved among eukaryotes. The protein 'ubiquitin' was named after it was found to be ubiquitously expressed in cells. Ubiquitination was first identified as a post-translational modification that mediates energy-consuming protein degradation by the proteasome. After half a century, the manifold functions of ubiquitin are widely recognized to play key roles in diverse molecular pathways and physiological processes. Compared to humans, the number of enzymes related to ubiquitination is almost twice as high in plant species, such as Arabidopsis and rice, suggesting that this modification plays a critical role in many aspects of plant physiology including development and environmental stress responses. Here, we summarize and discuss recent knowledge of ubiquitination focusing on the regulation of membrane trafficking in plants. Ubiquitination of plasma membrane-localized proteins often leads to endocytosis and vacuolar targeting. In addition to cargo proteins, ubiquitination of membrane trafficking regulators regulates the morphodynamics of the endomembrane system. Thus, throughout this review, we focus on the physiological responses regulated by ubiquitination and their underlying mechanisms to clarify what is already known and what would be interesting to investigate in the future.

Tissue-Specific Regulation of Vesicular Trafficking Mediated by Rab-GEF Complex MON1/CCZ1 From Solanum chilense Increases Salt Stress Tolerance in Arabidopsis thaliana.

Salt stress constrains the development and growth of plants. To tolerate it, mechanisms of endocytosis and vacuolar compartmentalization of Na+ are induced. In this work, the genes that encode a putative activator of vesicular trafficking called MON1/CCZ1 from Solanum chilense, SchMON1 and SchCCZ1, were co-expressed in roots of Arabidopsis thaliana to determine whether the increase in prevacuolar vesicular trafficking also increases the Na+ compartmentalization capacity and tolerance. Initially, we demonstrated that both SchMON1 and SchCCZ1 genes rescued the dwarf phenotype of both A. thaliana mon1-1 and ccz1a/b mutants associated with the loss of function, and both proteins colocalized with their functional targets, RabF and RabG, in endosomes. Transgenic A. thaliana plants co-expressing these genes improved salt stress tolerance compared to wild type plants, with SchMON1 contributing the most. At the sub-cellular level, co-expression of SchMON1/SchCCZ1 reduced ROS levels and increased endocytic activity, and number of acidic structures associated with autophagosomes. Notably, greater Na+ accumulation in vacuoles of cortex and endodermis was evidenced in the SchMON1 genotype. Molecular analysis of gene expression in each genotype supported these results. Altogether, our analysis shows that root activation of prevacuolar vesicular trafficking mediated by MON1/CCZ1 emerges as a promising physiological molecular mechanism to increase tolerance to salt stress in crops of economic interest.

The GTPase RAB6 is required for stem cell maintenance and cell migration in the gut epithelium.

Intestinal epithelial cells, which are instrumental in nutrient absorption, fluid regulation, and pathogen defense, undergo continuous proliferation and differentiation within the intestinal crypts, migrating towards the luminal surface where they are eventually shed. RAB GTPases are key regulators of intracellular vesicular trafficking and are involved in various cellular processes, including cell migration and polarity. Here, we investigated the role of RAB6 in the development and maintenance of the gut epithelium. We generated conditional knockout mice with RAB6 specifically deleted in the gut epithelium. We found that deletion of the Rab6a gene resulted in embryonic lethality. In adult mice, RAB6 depletion led to altered villus architecture and impaired junction integrity without affecting the segregation of apical and basolateral membrane domains. Further, RAB6 depletion slowed down cell migration and adversely affected both cell proliferation and stem cell maintenance. Notably, the absence of RAB6 resulted in a diminished number of functional stem cells, as evidenced by the rapid death of isolated crypts from Rab6a KO mice when cultured as 3D organoids. Together, these results underscore the essential role of RAB6 in maintaining gut epithelial homeostasis.