1
|
Díaz JM, Dozois CM, Avelar-González FJ, Hernández-Cuellar E, Pokharel P, de Santiago AS, Guerrero-Barrera AL. The Vacuolating Autotransporter Toxin (Vat) of Escherichia coli Causes Cell Cytoskeleton Changes and Produces Non-lysosomal Vacuole Formation in Bladder Epithelial Cells. Front Cell Infect Microbiol 2020; 10:299. [PMID: 32670893 PMCID: PMC7332727 DOI: 10.3389/fcimb.2020.00299] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2019] [Accepted: 05/19/2020] [Indexed: 12/13/2022] Open
Abstract
Urinary tract infections (UTIs) affect more than 150 million people, with a cost of over 3.5 billion dollars, each year. Escherichia coli is associated with 70–80% of UTIs. Uropathogenic E. coli (UPEC) has virulence factors including adhesins, siderophores, and toxins that damage host cells. Vacuolating autotransporter toxin (Vat) is a member of serine protease autotransporter proteins of Enterobacteriaceae (SPATEs) present in some uropathogenic E. coli (UPEC) strains. Vat has been identified in 20–36% of UPEC and is present in almost 68% of urosepsis isolates. However, the mechanism of action of Vat on host cells is not well-known. Thus, in this study the effect of Vat in a urothelium model of bladder cells was investigated. Several toxin concentrations were tested for different time periods, resulting in 15–47% of cellular damage as measured by the LDH assay. Vat induced vacuole formation on the urothelium model in a time-dependent manner. Vat treatment showed loss of the intercellular contacts on the bladder cell monolayer, observed by Scanning Electron Microscopy. This was also shown using antibodies against ZO-1 and occludin by immunofluorescence. Additionally, changes in permeability of the epithelial monolayer was demonstrated with a fluorescence-based permeability assay. Cellular damage was also evaluated by the identification of cytoskeletal changes produced by Vat. Thus, after Vat treatment, cells presented F-actin distribution changes and loss of stress fibers in comparison with control cells. Vat also modified tubulin, but it was not found to affect Arp3 distribution. In order to find the nature of the vacuoles generated by Vat, the Lysotracker deep red fluorescent dye for the detection of acidic organelles was used. Cells treated with Vat showed generation of some vacuoles without acidic content. An ex vivo experiment with mouse bladder exposed to Vat demonstrated loss of integrity of the urothelium. In conclusion, Vat induced cellular damage, vacuole formation, and urothelial barrier dysregulation of bladder epithelial cells. Further studies are needed to elucidate the role of these vacuoles induced by Vat and their relationship with the pathogenesis of urinary tract infection.
Collapse
Affiliation(s)
- Juan Manuel Díaz
- Departamento de Morfología, Universidad Autónoma de Aguascalientes (UAA), Aguascalientes, Mexico
| | - Charles M Dozois
- Institut National de Recherche Scientifique (INRS)-Centre Armand-Fappier Santé Biotechnologie, Laval, QC, Canada
| | | | | | - Pravil Pokharel
- Institut National de Recherche Scientifique (INRS)-Centre Armand-Fappier Santé Biotechnologie, Laval, QC, Canada
| | | | | |
Collapse
|
2
|
Diabetes and exposure to peritoneal dialysis solutions alter tight junction proteins and glucose transporters of rat peritoneal mesothelial cells. Life Sci 2016; 161:78-89. [DOI: 10.1016/j.lfs.2016.07.018] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2015] [Revised: 07/25/2016] [Accepted: 07/30/2016] [Indexed: 01/08/2023]
|
3
|
Jaramillo-Juárez F, Macías-Pérez JR, Martínez-Saldaña MC, Avelar-González FJ, Loera-Muro VM, Hernández-Cuéllar EE, Jaramillo F, Reynaga HMG, Guerrero-Barrera AL. F-Actin Distribution Changes Provoked by Acetaminophen in the Proximal Tubule in Kidney of Adult Male Rat. ACTA ACUST UNITED AC 2016. [DOI: 10.4236/mr.2016.43005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
|
4
|
The Crystal Structure of Nitrosomonas europaea Sucrose Synthase Reveals Critical Conformational Changes and Insights into Sucrose Metabolism in Prokaryotes. J Bacteriol 2015; 197:2734-46. [PMID: 26013491 DOI: 10.1128/jb.00110-15] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2015] [Accepted: 05/19/2015] [Indexed: 11/20/2022] Open
Abstract
UNLABELLED In this paper we report the first crystal structure of a prokaryotic sucrose synthase from the nonphotosynthetic bacterium Nitrosomonas europaea. The obtained structure was in an open form, whereas the only other available structure, from the plant Arabidopsis thaliana, was in a closed conformation. Comparative structural analysis revealed a "hinge-latch" combination, which is critical to transition between the open and closed forms of the enzyme. The N. europaea sucrose synthase shares the same fold as the GT-B family of the retaining glycosyltransferases. In addition, a triad of conserved homologous catalytic residues in the family was shown to be functionally critical in the N. europaea sucrose synthase (Arg567, Lys572, and Glu663). This implies that sucrose synthase shares not only a common origin with the GT-B family but also a similar catalytic mechanism. The enzyme preferred transferring glucose from ADP-glucose rather than UDP-glucose like the eukaryotic counterparts. This predicts that these prokaryotic organisms have a different sucrose metabolic scenario from plants. Nucleotide preference determines where the glucose moiety is targeted after sucrose is degraded. IMPORTANCE We obtained biochemical and structural evidence of sucrose metabolism in nonphotosynthetic bacteria. Until now, only sucrose synthases from photosynthetic organisms have been characterized. Here, we provide the crystal structure of the sucrose synthase from the chemolithoautotroph N. europaea. The structure supported that the enzyme functions with an open/close induced fit mechanism. The enzyme prefers as the substrate adenine-based nucleotides rather than uridine-based like the eukaryotic counterparts, implying a strong connection between sucrose and glycogen metabolism in these bacteria. Mutagenesis data showed that the catalytic mechanism must be conserved not only in sucrose synthases but also in all other retaining GT-B glycosyltransferases.
Collapse
|
5
|
García-Hernández V, Flores-Maldonado C, Rincon-Heredia R, Verdejo-Torres O, Bonilla-Delgado J, Meneses-Morales I, Gariglio P, Contreras RG. EGF Regulates Claudin-2 and -4 Expression Through Src and STAT3 in MDCK Cells. J Cell Physiol 2014; 230:105-15. [DOI: 10.1002/jcp.24687] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2014] [Accepted: 05/22/2014] [Indexed: 12/20/2022]
Affiliation(s)
- Vicky García-Hernández
- Department of Physiology; Biophysics and Neurosciences; Center for Research and Advanced Studies (Cinvestav); México City México
| | - Catalina Flores-Maldonado
- Department of Physiology; Biophysics and Neurosciences; Center for Research and Advanced Studies (Cinvestav); México City México
| | - Ruth Rincon-Heredia
- Department of Physiology; Biophysics and Neurosciences; Center for Research and Advanced Studies (Cinvestav); México City México
- Department of Pharmacology; Center for Research and Advanced Studies (Cinvestav); México City México
| | - Odette Verdejo-Torres
- Department of Physiology; Biophysics and Neurosciences; Center for Research and Advanced Studies (Cinvestav); México City México
| | - José Bonilla-Delgado
- Laboratory of Genetics and Molecular Diagnosis; Research Unit; Hospital Juárez de México; México City México
| | - Ivan Meneses-Morales
- Breast Cancer investigation program; National Autonomous University of México (UNAM); México
- Department of Molecular Biology and Biotechnology; Biomedical Research Institute; National Autonomous University of México (UNAM); México
| | - Patricio Gariglio
- Department of Genetics and Molecular Biology; Center for Research and Advanced Studies (Cinvestav); México City México
| | - Rubén G. Contreras
- Department of Physiology; Biophysics and Neurosciences; Center for Research and Advanced Studies (Cinvestav); México City México
| |
Collapse
|
6
|
Retana C, Sanchez E, Perez-Lopez A, Cruz A, Lagunas J, Cruz C, Vital S, Reyes JL. Alterations of intercellular junctions in peritoneal mesothelial cells from patients undergoing dialysis: effect of retinoic Acid. Perit Dial Int 2014; 35:275-87. [PMID: 24584604 DOI: 10.3747/pdi.2012.00323] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2012] [Accepted: 10/01/2013] [Indexed: 11/15/2022] Open
Abstract
BACKGROUND Dialysis patients are classified according to their peritoneal permeability as low transporter (LT, low solute permeability) or high transporter (HT, high solute permeability). Tight junction (TJ) proteins are critical to maintain ions, molecules and water paracellular transport through peritoneum. Exposure to peritoneal dialysis solutions causes damage to TJ in human peritoneal mesothelial cells (HPMCs). We analyzed the quantity, distribution and function of TJ proteins: claudin-1, -2 and -8, ZO-1 and occludin, in HPMC cultures from LT and HT patients. Since all-trans retinoic acid (ATRA) might modify the expression of TJ proteins, we studied its effect on HPMCs. METHODS Control HPMCs were isolated from human omentum, while HT or LT cells were obtained from dialysis effluents. Cells were cultured in presence of ATRA 0, 50 or 100 nM. Transepithelial electrical resistance (TER) measurement, immunostaining and Western blot analyses were performed. RESULTS HT exhibited lower TER than control and LT monolayers. Immunofluorescence for TJ was weak and discontinuous along the cell contour, in LT and HT. Furthermore, claudin-1, occludin and ZO-1 expressions were decreased. In all groups, claudin-2 was localized at nuclei. We observed that ATRA improved TJ distribution and increased TJ expression in HT. This retinoid did not modify claudin-2 and -8 expressions. All-trans retinoic acid decreased TER in HT, but had no effect in LT. CONCLUSIONS Tight junctions were altered in HPMCs from dialyzed patients. The HT monolayer has lower TER than LT, which might be associated with the peritoneal permeability in these patients. ATRA might be a therapeutic alternative to maintain mesothelial integrity, since it improved TJ localization and expression.
Collapse
Affiliation(s)
- Carmen Retana
- Pharmacology Dept., Centre for Research and Advanced Studies National Polytechnic Institute, Mexico
| | - Elsa Sanchez
- Physiology, Biophysics and Neurosciences Dept., Centre for Research and Advanced Studies National Polytechnic Institute, Mexico
| | | | - Armando Cruz
- Unidad Medica Alta Especialidad, Hospital General la Raza, Instituto Mexicano del Seguro Social (IMSS), Mexico
| | - Jesus Lagunas
- Unidad Medica Alta Especialidad, Hospital General la Raza, Instituto Mexicano del Seguro Social (IMSS), Mexico
| | - Carmen Cruz
- Dept. of Nephrology, Hospital Regional No. 1 del IMSS, Mexico
| | - Socorro Vital
- Dept. of Nephrology, Hospital Juarez de Mexico, Mexico
| | - Jose L Reyes
- Physiology, Biophysics and Neurosciences Dept., Centre for Research and Advanced Studies National Polytechnic Institute, Mexico
| |
Collapse
|
7
|
Ouabain induces endocytosis and degradation of tight junction proteins through ERK1/2-dependent pathways. Exp Cell Res 2014; 320:108-18. [DOI: 10.1016/j.yexcr.2013.10.008] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2013] [Revised: 10/07/2013] [Accepted: 10/09/2013] [Indexed: 11/20/2022]
|
8
|
Retana C, Sanchez EI, Gonzalez S, Perez-Lopez A, Cruz A, Lagunas-Munoz J, Alfaro-Cruz C, Vital-Flores S, Reyes JL. Retinoic acid improves morphology of cultured peritoneal mesothelial cells from patients undergoing dialysis. PLoS One 2013; 8:e79678. [PMID: 24223992 PMCID: PMC3817121 DOI: 10.1371/journal.pone.0079678] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2013] [Accepted: 09/23/2013] [Indexed: 01/24/2023] Open
Abstract
Patients undergoing continuous ambulatory peritoneal dialysis are classified according to their peritoneal permeability as low transporter (low solute permeability) or High transporter (high solute permeability). Factors that determine the differences in permeability between them have not been fully disclosed. We investigated morphological features of cultured human peritoneal mesothelial cells from low or high transporter patients and its response to All trans retinoic Acid (ATRA, vitamin A active metabolite), as compared to non-uremic human peritoneal mesothelial cells. Control cells were isolated from human omentum. High or low transporter cells were obtained from dialysis effluents. Cells were cultured in media containing ATRA (0, 50, 100 or 200 nM). We studied length and distribution of microvilli and cilia (scanning electron microscopy), epithelial (cytokeratin, claudin-1, ZO-1 and occludin) and mesenchymal (vimentin and α-smooth muscle actin) transition markers by immunofluorescence and Western blot, and transforming growth factor β1 expression by Western blot. Low and high transporter exhibited hypertrophic cells, reduction in claudin-1, occludin and ZO-1 expression, cytokeratin and vimentin disorganization and positive α-smooth muscle actin label. Vimentin, α-smooth muscle actin and transforming growth factor-β1 were overexpressed in low transporter. Ciliated cells were diminished in low and high transporters. Microvilli number and length were severely reduced in high transporter. ATRA reduced hypertrophic cells number in low transporter. It also improved cytokeratin and vimentin organization, decreased vimentin and α-smooth muscle actin expression, and increased claudin 1, occludin and ZO-1 expression, in low and high transporter. In low transporter, ATRA reduced transforming growth factor-β1 expression. ATRA augmented percentage of ciliated cells in low and high transporter. It also augmented cilia length in high transporter. Alterations in structure, epithelial mesenchymal markers and transforming growth factor-β1 expression were differential between low and high transporter. Beneficial effects of ATRA were improved human peritoneal mesothelial cells morphology tending to normalize structures.
Collapse
Affiliation(s)
- Carmen Retana
- Pharmacology Department Centre for Research and Advanced Studies National Polytechnic Institute, Mexico, D.F., Mexico
| | - Elsa I. Sanchez
- Physiology, Biophysics and Neurosciences Department Centre for Research and Advanced Studies National Polytechnic Institute, Mexico, D.F., Mexico
| | - Sirenia Gonzalez
- Central Laboratories Centre for Research and Advanced Studies National Polytechnic Institute, Mexico, D.F., Mexico
| | - Alejandro Perez-Lopez
- Nephrology Department, Hospital Central Norte de Petroleos Mexicanos, Mexico, D.F., Mexico
| | - Armando Cruz
- Nephrology and Gynecology Departments Unidad Medica Alta Especialidad, Hospital General la Raza, Instituto Mexicano del Seguro Social, Mexico, D.F., Mexico
| | - Jesus Lagunas-Munoz
- Nephrology and Gynecology Departments Unidad Medica Alta Especialidad, Hospital General la Raza, Instituto Mexicano del Seguro Social, Mexico, D.F., Mexico
| | - Carmen Alfaro-Cruz
- Nephrology. Dept. Hospital Regional No. 1 del Instituto Mexicano del Seguro Social, Mexico, D.F., Mexico
| | | | - José L. Reyes
- Physiology, Biophysics and Neurosciences Department Centre for Research and Advanced Studies National Polytechnic Institute, Mexico, D.F., Mexico
| |
Collapse
|
9
|
Díaz EM, Vicente-Manzanares M, Sacristan M, Vicente C, Legaz ME. Fungal lectin of Peltigera canina induces chemotropism of compatible Nostoc cells by constriction-relaxation pulses of cyanobiont cytoskeleton. PLANT SIGNALING & BEHAVIOR 2011; 6:1525-36. [PMID: 21897128 PMCID: PMC3256381 DOI: 10.4161/psb.6.10.16687] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/26/2011] [Revised: 06/30/2011] [Accepted: 07/06/2011] [Indexed: 05/31/2023]
Abstract
A glycosylated arginase acting as a fungal lectin from Peltigera canina is able to produce recruitment of cyanobiont Nostoc cells and their adhesion to the hyphal surface. This implies that the cyanobiont would develop organelles to motility towards the chemoattractant. However when visualized by transmission electron microscopy, Nostoc cells recently isolated from P. canina thallus do not reveal any motile, superficial organelles, although their surface was covered by small spindles and serrated layer related to gliding. The use of S-(3,4-dichlorobenzyl)isothiourea, blebbistatin, phalloidin and latrunculin A provide circumstantial evidence that actin microfilaments rather than MreB, the actin-like protein from prokaryota, and, probably, an ATPase which develops contractile function similar to that of myosin II, are involved in cell motility. These experimental facts, the absence of superficial elements (fimbriae, pili or flagellum) related to cell movement, and the appearance of sunken cells during of after movement verified by scanning electron microscopy, support the hypothesis that the motility of lichen cyanobionts could be achieved by contraction-relaxation episodes of the cytoskeleton induced by fungal lectin act as a chemoattractant.
Collapse
Affiliation(s)
- Eva Maria Díaz
- Intercellular Communication in Plant Symbiosis Team; Faculty of Biology; Madrid, Spain
| | | | - Mara Sacristan
- Intercellular Communication in Plant Symbiosis Team; Faculty of Biology; Madrid, Spain
| | - Carlos Vicente
- Intercellular Communication in Plant Symbiosis Team; Faculty of Biology; Madrid, Spain
| | - Maria-Estrella Legaz
- Intercellular Communication in Plant Symbiosis Team; Faculty of Biology; Madrid, Spain
| |
Collapse
|
10
|
Participation of actin on Giardia lamblia growth and encystation. PLoS One 2009; 4:e7156. [PMID: 19774081 PMCID: PMC2743995 DOI: 10.1371/journal.pone.0007156] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2009] [Accepted: 08/26/2009] [Indexed: 12/31/2022] Open
Abstract
Background Microfilaments play a determinant role in different cell processes such as: motility, cell division, phagocytosis and intracellular transport; however, these structures are poorly understood in the parasite Giardia lamblia. Methodology and Principal Findings By confocal microscopy using TRITC-phalloidin, we found structured actin distributed in the entire trophozoite, the label stand out at the ventral disc, median body, flagella and around the nuclei. During Giardia encystation, a sequence of morphological changes concurrent to modifications on the distribution of structured actin and in the expression of actin mRNA were observed. To elucidate whether actin participates actively on growth and encystation, cells were treated with Cytochalasin D, Latrunculin A and Jasplakinolide and analyzed by confocal and scanning electron microscopy. All drugs caused a growth reduction (27 to 45%) and changes on the distribution of actin. Besides, 60 to 80% of trophozoites treated with the drugs, exhibited damage at the caudal region, alterations in the flagella and wrinkles-like on the plasma membrane. The drugs also altered the cyst-yield and the morphology, scanning electron microscopy revealed diminished cytokinesis, cysts with damages in the wall and alterations in the size and on the intermembranal space. Furthermore, the drugs caused a significant reduction of the intensity of flourescence-labeled CWP1 on ESV and on cyst wall, this was coincident with a reduction of CWP1 gene expression (34%). Conclusions and Significance All our results, indicated an important role of actin in the morphology, growth and encystation and indirectly suggested an actin role in gene expression.
Collapse
|
11
|
Flores-Benitez D, Rincon-Heredia R, Razgado LF, Larre I, Cereijido M, Contreras RG. Control of tight junctional sealing: roles of epidermal growth factor and prostaglandin E2. Am J Physiol Cell Physiol 2009; 297:C611-20. [PMID: 19570890 DOI: 10.1152/ajpcell.00622.2008] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Epithelia can adjust the permeability of the paracellular permeation route by regulating the degree of sealing of the tight junction. This is reflected by a transepithelial electrical resistance (TER) ranging from a few tenths to several thousand ohms times square centimeters, depending on the difference in composition between the fluid in the lumen and the interstitial fluid. Although teleologically sound, such correlation requires a physiological explanation. We have previously shown that urine extracts from different animal species increase the TER of Madin-Darby canine kidney (MDCK) monolayers and that these effects are mediated by epidermal growth factor (EGF) contained in the flowing intratubular fluid that eventually reaches the urine. This increase in TER is accompanied by an enhanced expression of claudin-4 (cln-4) and a decrement of cln-2. These changes are transient, peaking at approximately 16 h and returning to control values in approximately 24 h. In the present work we investigated how EGF provokes this transient response, and we found that the activation of extracellular-regulated kinases 1/2 (ERK1/2) by EGF is essential to increase TER and cln-4 content, but it does not appear to participate in cln-2 downregulation. On the other hand, prostaglandin synthesis, stimulated by EGF, functions as a negative feedback, turning off the signal initiated by EGF. Thus, PGE(2) blocks ERK1/2 by a mechanism that involves the G alpha(s) protein, adenylyl cyclase as well as protein kinase A in MDCK cells. In summary, the permeability of a given segment of the nephron depends on the expression of different claudin types, which may be modulated by EGF and prostaglandins.
Collapse
Affiliation(s)
- D Flores-Benitez
- Department of Physiology, Biophysics and Neurosciences, Center for Research and Advanced Studies (CINVESTAV), Mexico City, Mexico
| | | | | | | | | | | |
Collapse
|
12
|
Flores-Benítez D, Ruiz-Cabrera A, Flores-Maldonado C, Shoshani L, Cereijido M, Contreras RG. Control of tight junctional sealing: role of epidermal growth factor. Am J Physiol Renal Physiol 2007; 292:F828-36. [PMID: 17077385 DOI: 10.1152/ajprenal.00369.2006] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
Epithelia can adjust the permeability of their paracellular permeation route to physiological requirements, pathological conditions, and pharmacological challenges. This is reflected by a transepithelial electrical resistance (TER) ranging from a few tenth to several thousands Ω·cm2, depending on the degree of sealing of the tight junction (TJ). The present work is part of an effort to understand the causes and mechanisms underlying these adaptations. We observed that an extract of human urine (hDLU) increases TER in a concentration- and time-dependent manner and is more effective when added from the basolateral side of cultured monolayers of Madin-Darby canine kidney cells than from the apical one. We found that its main TER-increasing component is epidermal growth factor (hEGF), as depletion of this peptide with specific antibodies, or inhibition of its receptor with PD153035, abolishes its effect. Since the permeability of the TJ depends on the expression of several species of membrane proteins, chiefly claudins, we explored whether hDLU can affect five members of the claudin family, the three known members of the ZO family, and occludin. EGF present in hDLU decreases the content of claudins-1 and -2 as well as delocalizes them from the TJ and increases the content of claudin-4. As expected from the fact that the degree of sealing of the TJ must be a physiologically regulated parameter, besides of hEGF, we also found that hDLU appears to contain also other components that decrease TER, claudin-4 and -7, and that seem to act with different kinetics than the TER-increasing ones.
Collapse
Affiliation(s)
- D Flores-Benítez
- Department of Physiology, Universidad Nacional Autónoma de México, México
| | | | | | | | | | | |
Collapse
|
13
|
Patrón S A, Mondragón M, González S, Ambrosio JR, Guerrero B AL, Mondragón R. Identification and purification of actin from the subpellicular network of Toxoplasma gondii tachyzoites. Int J Parasitol 2005; 35:883-94. [PMID: 15970197 DOI: 10.1016/j.ijpara.2005.03.016] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2005] [Revised: 03/22/2005] [Accepted: 03/31/2005] [Indexed: 11/16/2022]
Abstract
Toxoplasma gondii infects cells through dynamic events dependent on actin. Although the presence of cortical actin has been widely suggested, visualisation and localisation of actin filaments has not been reported. The subpellicular cytoskeleton network is a recently described structure possibly involved in the dynamic events. Using non-ionic detergent extractions, the cortical cytoskeleton network was enriched and used for the isolation and identification of actin. Actin was detected by Western blots in extracts of cytoskeleton networks, and it was localised by gold staining in the network and in both the apical end and the posterior polar ring. Actin was isolated from subpellicular cytoskeleton extracts by binding to DNase I, and it polymerised in vitro as filaments that were gold-decorated by a monoclonal anti-actin antibody. Filaments bound the subfragment 1 of heavy meromyosin, although with atypical arrangements in comparison with the arrowheads observed in muscle actin filaments. Treatment with cytochalasin D and colchicine altered the structural organisation of the subpellicular network indicating the participation of actin filaments and microtubules in the maintenance of its structure. Actin filaments and microtubules, in the subpellicular network, participate reciprocally in the maintaining of the parasite's shape and the gliding motility.
Collapse
Affiliation(s)
- Araceli Patrón S
- Departamento de Bioquímica, Centro de Investigación y Estudios Avanzados del IPN. Av. Instituto Politécnico Nacional No 2508. Col. Sn Pedro Zacatenco, Del. Gustavo A. Madero., México
| | | | | | | | | | | |
Collapse
|
14
|
Guerrero-Barrera AL, de la Garza M, Mondragón R, Garcı A-Cuéllar C, Segura-Nieto M. Actin-related proteins in Actinobacillus pleuropneumoniae and their interactions with actin-binding proteins. MICROBIOLOGY (READING, ENGLAND) 1999; 145 ( Pt 11):3235-3244. [PMID: 10589733 DOI: 10.1099/00221287-145-11-3235] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
A group of prokaryotic actin-related proteins (PARP) with an Mr of 43000 was detected in Actinobacillus pleuropneumoniae. These proteins were enriched by a depolymerization/polymerization cycle, under similar conditions to those used to polymerize muscle actin, and purified by affinity chromatography on a DNase I-Sepharose column. Three isoforms of A. pleuropneumoniae PARP (Ap-PARP) with pI values of 5.8, 6.15 and 6.2 were detected. Ap-PARP were recognized by four different anti-actin antibodies (one anti-muscle and three anti-cytoplasmic isoforms). Ap-PARP were also recognized by antibodies against Anabaena variabilis PARP (Av-PARP) and against actin-binding proteins such as alpha-actinin and spectrin, and also by a monoclonal antibody against heat-shock cognate protein 70 (Hsc70). Specific binding of phalloidin to Ap-PARP was detected both in permeabilized cells and in vitro. Purified Ap-PARP can polymerize under similar conditions to those required for skeletal muscle actin polymerization and the filaments formed appear to be decorated with myosin subfragment-1(S1) as observed by transmission electron microscopy. The amino acid composition of Ap-PARP revealed more similarities to muscle gamma-actin and the cytoplasmic beta-actin isoform than to eukaryotic actin-related proteins.
Collapse
Affiliation(s)
- Alma L Guerrero-Barrera
- Departamento de Biologı́a Celular, Centro de Investigación y de Estudios Avanzados del IPN, Apartado Postal 14-740, México, DF 07000, Mexico1
| | - Mireya de la Garza
- Departamento de Biologı́a Celular, Centro de Investigación y de Estudios Avanzados del IPN, Apartado Postal 14-740, México, DF 07000, Mexico1
| | - Ricardo Mondragón
- Departamento de Inmunologı́a, Escuela Nacional de Ciencias Biológicas IPN, Prolongación de Carpio y Plan de Ayala s/n, México, DF 11340, Mexico3
| | - Claudia Garcı A-Cuéllar
- División de Investigación Básica, Instituto Nacional de Cancerologı́a, San Fernando No 22, Tlalpan, DF 14000, Mexico4
- Departamento de Biologı́a Celular, Centro de Investigación y de Estudios Avanzados del IPN, Apartado Postal 14-740, México, DF 07000, Mexico1
| | - Magdalena Segura-Nieto
- Departamento de Ingenierı́a Genética de Plantas, Centro de Investigación y de Estudios Avanzados del IPN, Apartado Postal 629, Irapuato, Gto. 36500, Mexico2
| |
Collapse
|
15
|
Abstract
The elastic properties of DNA and the contractile activities of enzymes involved in transcription, translation and supercoiling may have contributed to the ability of early cells (protocells) to withstand turgor pressure. In the hypothesis proposed here, resistance to turgor resulted from (1) the elastic properties of DNA which was connected to the membrane by association with positively charged lipids and with membrane peptides, (2) the coupled transcription-translation-insertion of peptides into membrane--transertion--which connected membranes with phase-condensed DNA, and (3) the action of topoisomerases which supercoiled and shortened DNA. The existence of a negative feedback system is also proposed to explain how weakened regions of membrane were preferentially strengthened. It may prove possible to test this hypothesis by studying transertion using optical tweezers and by studying wall-less L-form bacteria.
Collapse
Affiliation(s)
- V Norris
- IFR 'Systèmes Intégrés' Laboratoire de Microbiologie, Faculté des Sciences et Techniques, Université de Rouen, Mont Saint Aignan, France.
| | | | | | | |
Collapse
|
16
|
Freestone P, Grant S, Trinei M, Onoda T, Norris V. Protein phosphorylation in Escherichia coli L. form NC-7. MICROBIOLOGY (READING, ENGLAND) 1998; 144 ( Pt 12):3289-3295. [PMID: 9884220 DOI: 10.1099/00221287-144-12-3289] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Wall-less L-forms of Escherichia coli constitute an interesting, and relatively underused, model system for numerous studies of bacterial physiology including the cell cycle, intracellular structure and protein phosphorylation. Total extracts of the L-form revealed a pattern of protein phosphorylation similar to that of an enteropathogenic strain but very different from its parental K-12 strain. In particular, the L-form extract revealed phosphorylation on tyrosine of a protein important in pathogenesis, TypA, and calcium-specific phosphorylation of a 40 kDa protein. Two new phosphoproteins were identified in the L-form as the DNA-binding protein Dps, and YfiD, a protein of 14 kDa with homology to pyruvate formate-lyase and a region containing a tRNA cluster in bacteriophage T5.
Collapse
Affiliation(s)
- P Freestone
- Department of Microbiology and Immunology, Medical Sciences Building, University of Leicester, Leicester LE1 9HN, UK
| | - S Grant
- Department of Microbiology and Immunology, Medical Sciences Building, University of Leicester, Leicester LE1 9HN, UK
| | - M Trinei
- Department of Microbiology and Immunology, Medical Sciences Building, University of Leicester, Leicester LE1 9HN, UK
| | - T Onoda
- Department of Biology, Faculty of Science, Shimane University, Matsue 690, Japan
| | - V Norris
- IFR 'Systèmes Intégrés', Laboratoire de Microbiologie, Faculté des Sciences et Techniques de Rouen, F76821 Mont Saint Aignan, France
| |
Collapse
|
17
|
Usmanova A, Astier C, Méjean C, Hubert F, Feinberg J, Benyamin Y, Roustan C. Coevolution of actin and associated proteins: an alpha-actinin-like protein in a cyanobacterium (Spirulina platensis). Comp Biochem Physiol B Biochem Mol Biol 1998; 120:693-700. [PMID: 9854817 DOI: 10.1016/s0305-0491(98)10065-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Actin, together with associated proteins, such as myosin, cross-linking or capping proteins, has been observed in all eukaryotic cells. Presence of actin or actin-like proteins has also been reported in prokaryotic organisms belonging to the cyanobacteria. Our aim was first to extend the characterization of an actin-like protein to another prokaryotic cell, i.e. Spirulina, then to compare the antigenic reactivity of this new protein with that of Synechocystis and skeletal actins. We observed that some of the conserved antigenic epitopes corresponded to actin regions known to interact with cross-linking proteins. We also report for the first time that alpha-actinin and filamin purified from chicken gizzard both interact with a prokaryotic actin-like protein. Finally, we searched for the occurrence of a cross-linking protein in these cyanobacteria and identified a 105-kDa protein as an alpha-actinin-like protein using specific antibodies.
Collapse
Affiliation(s)
- A Usmanova
- UMR 5539 (CNRS), Université de Montpellier 2, France
| | | | | | | | | | | | | |
Collapse
|
18
|
Kuroiwa T, Kuroiwa H, Sakai A, Takahashi H, Toda K, Itoh R. The division apparatus of plastids and mitochondria. INTERNATIONAL REVIEW OF CYTOLOGY 1998; 181:1-41. [PMID: 9522454 DOI: 10.1016/s0074-7696(08)60415-5] [Citation(s) in RCA: 162] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Mitochondria and plastids in eukaryotic cells contain distinct genomes and multiply in the cytoplasm by binary division of preexisting organelles. Mitochondrial and plastid nuclei are easily visualized as compartments in the matrix of organelles by high-resolution fluorescence microscopy and by immunoelectron microscopy using anti-DNA antibodies. Plastid and mitochondrial division can be clearly separated into two main events: division of the organelle nuclei, and then division of the rest of the organelles, the process of organellokinesis (mitochondriokinesis and plastidokinesis). The mechanical apparatus that regulates organellokinesis has remained undetermined. In 1986, the plastid-dividing apparatus (PD ring) for plastidokinesis was first identified by us in the primitive red alga Cyanidium caldarium RK-1. The PD ring is located in the cytoplasm outside the organelle envelope at the constricted isthmus of dividing organelles and has subsequently been found in all eukaryotic plants examined. We were also the first to identify the mitochondrion-dividing apparatus (MD ring) for mitochondriokinesis in the unicellular red alga Cyanidioschyzon merolae in 1993. Eukaryotic cell division is therefore controlled by at least three dividing apparata (rings), a contractile ring, an MD ring, and a PD ring, while bacterial division is controlled by a single bacterial contractile FtsZ ring. The aims of this review are to present the fine structure, process of formation, and contraction of the organelle-dividing apparatus, focusing on evolutionary conservation and diversion from the bacterial contractile ring.
Collapse
Affiliation(s)
- T Kuroiwa
- Department of Biological Sciences, Graduate School of Science, University of Tokyo, Japan
| | | | | | | | | | | |
Collapse
|
19
|
Abstract
The shape of Escherichia coli is strikingly simple compared to those of higher eukaryotes. In fact, the end result of E. coli morphogenesis is a cylindrical tube with hemispherical caps. It is argued that physical principles affect biological forms. In this view, genes code for products that contribute to the production of suitable structures for physical factors to act upon. After introduction of a physical model, the discussion is focused on the shape-maintaining (peptidoglycan) layer of E. coli. This is followed by a detailed analysis of the structural relationship of the cellular interior to the cytoplasmic membrane. A basic theme of this review is that the transcriptionally active nucleoid and the cytoplasmic translation machinery form a structural continuity with the growing cellular envelope. An attempt has been made to show how this dynamic relationship during the cell cycle affects cell polarity and how it leads to cell division.
Collapse
Affiliation(s)
- N Nanninga
- Institute for Molecular Cell Biology, BioCentrum Amsterdam, University of Amsterdam, The Netherlands.
| |
Collapse
|