Vol. 13 No. 4 December 2008
DOI: 10.2478/s11658-008-0019-4 Volume 13 (2008) pp 493-501 | |
Title | THE MITOCHONDRIAL LOCALIZATION OF RelB AND NFATx IN IMMATURE T CELLS |
Authors | Izabela Stasik, Andrzej Rapak, Ewa Zioło and Leon Strządała* |
Abstract | In order to exert their activity, transcription factors must be transported to the nucleus. Certain transcription factors have also been found on mitochondria. Here, the localization of RelB and NFATx in the mitochondrial fractions of normal thymocytes and thymic lymphoma cells is shown for the first time. CREB was only found in the nucleus, while p50 (NFκB) was found in both the nucleus and the cytoplasm, but outside the mitochondria. The translocation of transcription factors to the mitochondria is differentially regulated. Unlike RelB, which is always present in the mitochondrial fraction, NFATx appeared on the mitochondria in cells treated with ionomycin together with an immunosuppressant and inhibitor of calcineurin (FK506). This data reveals that the mitochondrial localization of some transcription factors is precisely controlled by a calcium signal sensitive to FK506 in T cells. |
Keywords | Mitochondrial translocation, Transcription factors, NFATx, RelB, FK506, Thymocytes, Thymic lymphoma |
Address and Contact Information | Laboratory of Tumor Molecular Immunobiology, Ludwik Hirszfeld Institute
of Immunology and Experimental Therapy, Polish Academy of Sciences,
ul. Weigla 12, 53-114 Wrocław, Poland * Author for co rrespondence: e-mail: strzadal@iitd.pan.wroc.pl, tel.: (+48) 71 370 9914 |
DOI: 10.2478/s11658-008-0021-x Volume 13 (2008) pp 502-513 | |
Title | STATISTICAL PROPERTIES OF THE DICHOTOMOUS NOISE GENERATED IN BIOCHEMICAL PROCESSES # |
Authors | Michał Kurzyński* |
Abstract | Dichotomous noise detected with the help of various single-molecule techniques convincingly reveals the actual occurrence of a multitude of conformational substates composing the native state of proteins. The nature of the stochastic dynamics of transitions between these substates is determined by the particular statistical properties of the noise observed. These involve nonexponential and possibly oscillatory time decay of the second order autocorrelation function, its relation to the third order autocorrelation function, and a relationship to dwell-time distribution densities and their correlations. Processes gated by specific conformational substates are distinguished from those with fluctuating barriers. This study throws light on the intriguing matter of the possibility of multiple stepping of the myosin motor along the actin filament per ATP molecule hydrolyzed. |
Keywords | Single-molecule techniques, Time autocorrelation functions, Dwelltime distribution densities, Molecular gear |
Address and Contact Information | Faculty of Physics, Adam Mickiewicz University, Umultowska 85,
61-614 Poznań, Poland # Paper authored by participants of the international conference: International Workshop on Ionic Channels, Szczyrk, Poland, May 27 - June 01, 2007. Publication cost was covered by the organisers of this meeting. * e-mail: kurzphys@amu.edu.pl |
DOI: 10.2478/s11658-008-0020-y Volume 13 (2008) pp 514-525 | |
Title | CALCIUM TRANSPORT BY MAMMARY SECRETORY CELLS: MECHANISMS UNDERLYING TRANSEPITHELIAL MOVEMENT |
Authors | David B. Shennan* |
Abstract | The secretion of calcium into milk by mammary epithelial cells is a fundamentally important process. Despite this, the mechanisms which underlie the movement of calcium across the lactating mammary gland are still poorly understood. There are, however, two models which describe the handling of calcium by mammary epithelial cells. On the one hand, a model which has existed for several decades, suggests that the vast majority of calcium enters milk via the Golgi secretory vesicle route. On the other hand, a new model has recently been proposed which implies that the active transport of calcium across the apical membrane of mammary secretory cells is central to milk calcium secretion. This short review examines the strengths and weaknesses of both models and suggests some experiments which could add to our understanding of mammary calcium transport. |
Keywords | Calcium, Mammary, Secretion |
Address and Contact Information | Strathclyde Institute of Pharmacy and Biomedical Sciences, University of
Strathclyde, Royal College, 204 George St, Glasgow UK G1 1XW, UK * E-mail: david.shennan@strath.ac.uk |
DOI: 10.2478/s11658-008-0018-5 Volume 13 (2008) pp 526-534 | |
Title | ON THE ROLE OF BALL AND CHAIN INTERACTIONS IN RECOVERY FROM THE INACTIVATION OF THE SHAKER POTASSIUM CHANNEL# |
Authors | Przemysław Borys* and Zbigniew J. Grzywna |
Abstract | We describe a new factor in the recovery from inactivation in the ball and chain model. We propose a model in which the tension from the chain may help pull the ball away from its binding site, reducing the duration of the inactivation period. A corresponding model was built and analysed. |
Keywords | Ion channels, Inactivation, Recovery from inactivation, Ball and chain model |
Address and Contact Information | Department of Physical Chemistry and Technology of Polymers, Section
of Physics and Applied Mathematics, Silesian University of Technology,
44-100 Gliwice, Ks. M. Strzody 9, Poland
# Paper authored by participants of the international conference: International Workshop on Ionic Channels, Szczyrk, Poland, May 27 - June 01, 2007. Publication cost was covered by the organisers of this meeting. * Author for correspondence; e-mail: pborys@dione.cc, tel./fax: +48 32 237 1509 |
DOI: 10.2478/s11658-008-0015-8 Volume 13 (2008) pp 535-552 | |
Title | ON THE POSSIBLE METHODS FOR THE MATHEMATICAL DESCRIPTION OF THE BALL AND CHAIN MODEL OF ION CHANNEL INACTIVATION # |
Authors | Krzysztof Małysiak* and Zbigniew J. Grzywna |
Abstract | Ion channels are large transmembrane proteins that are able to conduct small inorganic ions. They are characterized by high selectivity and the ability to gate, i.e. to modify their conductance in response to different stimuli. One of the types of gating follows the ball and chain model, according to which a part of the channel’s protein forms a ball connected with the intracellular side of the channel by a polypeptide chain. The ball is able to modify the conductance of the channel by properly binding to and plugging the channel pore. In this study, the polypeptide ball is treated as a Brownian particle, the movements of which are limited by the length of the chain. The probability density of the ball’s position is resolved by different diffusional operators – parabolic (including the case with drift), hyperbolic, and fractional. We show how those different approaches shed light on different aspects of the movement. We also comment on some features of the survival probabilities (which are ready to be compared with electrophysiological measurements) for issues based on the above operators. |
Keywords | Voltage-gated ion channel, N-inactivation, Hyperbolic diffusion, Subdiffusion |
Address and Contact Information | Department of Physical Chemistry and Technology of Polymers, Section of Physics
and Applied Mathematics, Silesian University of Technology, Strzody 9,
44-100 Gliwice, Poland # Paper authored by participants of the international conference: International Workshop on Ionic Channels, Szczyrk, Poland, May 27 - June 01, 2007. Publication cost was covered by the organisers of this meeting. * Author for correspondence; e-mail: krzysztof.malysiak@polsl.pl |
DOI: 10.2478/s11658-008-0022-9 Volume 13 (2008) pp 553-569 | |
Title | IN VITRO EVALUATION OF THE CYTOTOXIC AND ANTIPROLIFERATIVE PROPERTIES OF RESVERATROL AND SEVERAL OF ITS ANALOGS |
Authors | Blase Billack*, Vijayalaxmi Radkar and Christelle Adiabouah |
Abstract | Resveratrol (RES), a component of red wine, possesses antiinflammatory properties. The studies described in the present work were aimed at evaluating the potential for RES and related stilbene analogs (piceatannol, PIC; pterostilbene, TPS; trans-stilbene, TS; and trans-stilbene oxide, TSO) to exhibit toxicity towards RAW 264.7 mouse macrophages. The effect of TS, TSO, RES and TPS on RAW 264.7 macrophage viability was determined by two standard methods: (a) the MTT assay and (b) the trypan blue dye exclusion test. Whereas macrophages were more sensitive to PIC (LC50 trypan ~ 1.3 µM) and to TPS (LC50 trypan ~ 4.0 µM and LC50 MTT ~ 8.3 µM) than to RES (LC50 trypan ~ 8.9 µM and LC50 MTT ~ 29.0 µM), they were relatively resistant to TSO (LC50 trypan ~ 61.0 µM and LC50 MTT > 100 µM) and to TS (LC50 trypan ≥ 5.0 µM and LC50 MTT ≥ 5.0 µM). The ability of selected stilbenes (RES, TPS and PIC) to exhibit growth inhibitory effects was also examined. Although RES and TPS were observed to inhibit cell proliferation in macrophages (IC50 ≤ 25 µM), these cells were resistant to growth inhibition by PIC (IC50 ≥ 50 µM). The data obtained in the present analysis demonstrate that substituted stilbene compounds such as RES have the capacity to exhibit cytotoxic and anti-proliferative activities in macrophages. |
Keywords | Resveratrol, Piceatannol, Pterostilbene, Stilbenes, Cell viability, Cell proliferation, Macrophages, TLR4 (-/-), Antioxidants |
Address and Contact Information | Department of Pharmaceutical Sciences, College of Pharmacy and Allied Health
Professions, St. John’s University, 8000 Utopia Parkway, Jamaica, NY 11439 USA * Author for correspondence; e-mail: billackb@stjohns.edu, tel.: 1-718-990-5657, f ax: 1-718-990-1877 |
DOI: 10.2478/s11658-008-0023-8 Volume 13 (2008) pp 570-584 | |
Title | THE IDENTIFICATION AND CHARACTERIZATION OF A NEW GTPBINDING PROTEIN (Gbp45) INVOLVED IN CELL PROLIFERATION AND DEATH RELATED TO MITOCHONDRIAL FUNCTION |
Authors | Yukimi Kira1 and Manabu Nishikawa2* |
Abstract | We describe the identification and characterization of a GTP-binding protein with a molecular weight of 45 kD (Gbp45). Gbp45 cDNA was found to overlap with a hypothetical human protein, PTD004, the sequence of which was previously deposited in the databases. The gene for PTD004 was recently found to be one of the ATPases, hOLA1 (human Obg-like ATPase 1). The Gbp45 gene encodes a protein of 396 amino acid residues. Immunocytochemical analysis and examination with GFP-tagged protein revealed that Gbp45 is primarily located in the cytosolic compartment. Immunoblot analysis showed that the Gbp45 protein is strongly expressed in the neuronal tissues and pancreas. T43N and T56N mutations resulted in a loss of Gbp45’s ability to bind to GTP and a loss of GTPase activity. In cultured cells, the transfection of wild-type Gbp45 accelerated cell proliferation, though T43N and T56N mutations induced cell death. Down-regulating Gbp45 expression decreased the cell proliferation rate and increased the rate of cell death induced by the inhibition of mitochondrial electron transport. These findings indicate that Gbp45 plays important roles in cell proliferation and death related to mitochondrial function. |
Keywords | Gbp45, GTPase, Small GTP-binding protein, Mutant, Cell growth, Mitochondria |
Address and Contact Information | Departments of 1Central Laboratory and 2Biochemistry, Osaka City University
Medical School, Osaka 545-8585, Japan * Author for correspondence; e-mail: nishikawa@med.osaka-cu.ac.jp, tel.: +81-6-6645- 3 722, fax: +81-6-6645-3721 |
DOI: 10.2478/s11658-008-0013-x Volume 13 (2008) pp 585-598 | |
Title | THE INFLUENCE OF LTS-4, A SAPONOSIDE FROM Lysimachia thyrsiflora L., ON HUMAN SKIN FIBROBLASTS AND HUMAN MELANOMA CELLS |
Authors | Agnieszka Galanty1*, Marta Michalik2, Łukasz Sędek2 and Irma Podolak1 |
Abstract | We investigated the effect of a triterpene saponoside from Lysimachia thyrsiflora L. upon the viability, proliferation, morphology and cell motility of human melanoma HTB-140 cells and human skin fibroblasts (HSFs). The compound, denoted LTS-4, decreased the viability and rate of cell growth of both cell types in a time- and dose-dependent manner, and proved cytotoxic against cancer cells at significantly lower concentrations than for fibroblasts. LTS-4 also affected the morphology of the examined cells, causing vacuolisation and actin cytoskeleton disintegration, and had an inhibitory effect on the tumour cell motility. |
Keywords | Triterpene saponoside, Cytotoxicity, Lysimachia thyrsiflora L., Melanoma, Fibroblasts |
Address and Contact Information | 1Department of Pharmacognosy, Faculty of Pharmacy, Jagiellonian University,
ul. Medyczna 9, 30-688 Kraków, Poland, 2Department of Cell Biology, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, ul. Gronostajowa 7, 30-387 Kraków, Poland * Aut hor for correspondence: e-mail: mfgalant@cyf-kr.edu.pl |
DOI: 10.2478/s11658-008-0025-6 Volume 13 (2008) pp 599-613 | |
Title | REGULATION OF HUMAN ALDOKETOREDUCTASE 1C3 (AKR1C3) GENE EXPRESSION IN THE ADIPOSE TISSUE |
Authors | Per-Arne Svensson§, Britt G. Gabrielsson§, Margareta Jernas, Anders Gummesson and Kajsa Sjöholm* |
Abstract | Aldoketoreductase 1C3 (AKR1C3) is a functional prostaglandin F synthase and a negative modulator of the availability of ligands for the nuclear receptor peroxisome proliferator-activated receptor-gamma (PPARγ). AKR1C3 expression is known to be associated with adiposity, one of the components of the metabolic syndrome. The aim of this study was to characterize the expression of AKR1C3 in the adipose tissue and adipocytes and to investigate its potential role in the metabolic syndrome. Using microarray analysis and realtime PCR, we studied the expression of AKR1C3 in adipose tissue samples from obese subjects with or without metabolic complications, during very low calorie diet-induced weight loss, and its expression in isolated human adipocytes of different sizes. The adipose tissue AKR1C3 expression levels were marginally lower in obese subjects with the metabolic syndrome compared with the levels in healthy obese subjects when analyzed using microarray (p = 0.078) and realtime PCR (p < 0.05), suggesting a secondary or compensatory effect. The adipose tissue mRNA levels of AKR1C3 were reduced during and after dietinduced weight-loss compared to the levels before the start of the diet (p < 0.001 at all time-points). The gene expression of AKR1C3 correlated with both adipose tissue mRNA levels and serum levels of leptin before the start of the diet (p < 0.05 and p < 0.01, respectively). Furthermore, large adipocytes displayed a higher expression of AKR1C3 than small adipocytes (1.5-fold, p < 0.01). In conclusion, adipose tissue AKR1C3 expression may be affected by metabolic disease, and its levels are significantly reduced in response to dietinduced weight loss and correlate with leptin levels. |
Keywords | Metabolic syndrome, Adipose tissue, Adipocytes, Diet-induced weight loss, Aldoketoreductase 1C3, 15-deoxy-12,14-prostaglandin J2 |
Address and Contact Information | Sahlgrenska Center for Cardiovascular and Metabolic Research, Department of
Molecular and Clinical Medicine, Institute of Medicine, Sahlgrenska Academy
at the University of Gothenburg, SE-413 45 Gothenburg, Sweden §These authors contributed equally to this study * Author for correspondence. e-mail: kajsa.sjoholm@medic.gu.se, tel.: +46 31 3423029, f ax +46 31 418527 |
DOI: 10.2478/s11658-008-0028-3 Volume 13 (2008) pp 614-620 | |
Title | GENE TRAPPING: AN ANTIBODY-DEPENDENT APPROACH FOR VERIFYING INTEGRATION IN YOUR FAVORITE GENE |
Authors | Anna Gorelik, Tamar Sapir and Orly Reiner* |
Abstract | Gene trapping is used to introduce genome-wide insertional mutations in embryonic stem cells. Determining the integration site is based on highthroughput PCR, which has inevitable possibilities for mistakes, thus necessitating clone verification prior to the generation of mutant mice. Here, we propose a rapid method to validate gene identity based on the fact that many high throughput gene-trapping integrations result in fusion proteins encompassing the N-terminal portion of the gene of interest and LacZ being expressed in embryonic stem cells. Our method utilizes an immunoprecipitation assay using a specific N-terminal-directed antibody to the protein product of the gene of interest followed by a color LacZ assay of the immunoprecipitate, strongly supporting the formation of a fusion protein when the color develops. |
Keywords | Gene-trap, LacZ fusion protein, Integration site |
Address and Contact Information | Department of Molecular Genetics, The Weizmann Institute of Science,
76100 Rehovot, Israel * Author for correspondence. e-mail: orly.reiner@weizmann.ac.il |
DOI: 10.2478/s11658-008-0026-5 Volume 13 (2008) pp 621-631 | |
Title | THE EFFECT OF CALNEXIN DELETION ON THE EXPRESSION LEVEL OF BINDING PROTEIN (BiP) UNDER HEAT STRESS CONDITIONS IN Saccharomyces cerevisiae |
Authors | Huili Zhang1, Bingjie Hu1, Yanyan Ji1, Akio Kato2 and Youtao Song1* |
Abstract | In order to investigate the effect of calnexin deletion on the induction of the main ER molecular chaperone BiP, we cultured the wild-type and calnexin-disrupted Saccharomyces cerevisiae strains under normal and stressed conditions. The growth rate of the calnexin-disrupted yeast was almost the same as that of the wild-type yeast under those conditions. However, the induced level of BiP mRNA in the ER was evidently higher in calnexin-disrupted S. cerevisiae than in the wild-type at 37oC, but was almost the same in the two strains under normal conditions. The Western blot analysis results for BiP protein expression in the ER showed a parallel in the mRNA levels in the two strains. It is suggested that under heat stress conditions, the induction of BiP in the ER might recover part of the function of calnexin in calnexin-disrupted yeast, and result in the same growth rate as in wild-type yeast. |
Keywords | Calnexin, Molecular chaperone, BiP, Heat stress |
Address and Contact Information | 1Department of Life Science, Liaoning University, Shenyang 110036, China, 2Department of Biological Chemistry, Yamaguchi University, Yamaguchi 753-8515, Japan * Author for correspondence: e-mail: ysong@lnu.edu.cn, tel: +86-24-62202280, fax: +86-24-86864476 |
DOI: 10.2478/s11658-008-0027-4 Volume 13 (2008) pp 632-648 | |
Title | EHDS ARE SERINE PHOSPHOPROTEINS: EHD1 PHOSPHORYLATION IS ENHANCED BY SERUM STIMULATION |
Authors | Boris Fichtman1, Liat Ravid2, Debora Rapaport and Mia Horowitz* |
Abstract | Endocytic processes are mediated by multiple protein-protein interacting modules and regulated by phosphorylation and dephosphorylation. The Eps15 homology domain containing protein 1 (EHD1) has been implicated in regulating recycling of proteins, internalized both in clathrin-dependent and clathrin-independent endocytic pathways, from the recycling compartment to the plasma membrane. EHD1 was found in a complex with clathrin, adaptor protein complex-2 (AP-2) and insulin-like growth factor-1 receptor (IGF-1R), and was shown to interact with Rabenosyn-5, SNAP29, EHBP1 (EH domain binding protein 1) and syndapin I and II. In this study, we show that EHD1, like the other human EHDs, undergoes serine-phosphorylation. Our results also indicate that EHD1 is a serum-inducible serine-phosphoprotein and that PKC (protein kinase C) is one of its kinases. In addition, we show that inhibitors of clathrin-mediated endocytosis decrease EHD1 phosphorylation, while inhibitors of caveolinmediated endocytosis do not affect EHD1 phosphorylation. The results of experiments in which inhibitors of endocytosis were employed strongly suggest that EHD1 phosphorylation occurs between early endosomes and the endocytic recycling compartment. |
Keywords | Endocytosis, EHD1, EH domain, Phosphorylation |
Address and Contact Information | Department of Cell Research and Immunology, Faculty of Life Sciences,
Tel-Aviv University, Ramat Aviv 69978, Israel * Author for correspondence: e-mail: horwitzm@post.tau.ac.il; 1Current address: University of California San Diego, CA 92093, USA, 2 Current address: The Weizmann Institute of Science, Rehovot, 76100, Israel |
DOI: 10.2478/s11658-008-0029-2 Volume 13 (2008) pp 649-655 | |
Title | ERYTHROPOIETIN AFFECTS GABAERGIC TRANSMISSION IN HIPPOCAMPAL NEURONS in vitro |
Authors | Tomasz Wójtowicz* and Jerzy W. Mozrzymas |
Abstract | Erythropoietin is a potent regulator of erythropoiesis. It acts via the specific membrane receptor (EpoR). Erythropoietin is also known to be present in the central nervous system, and its concentration and the expression of EpoR change during development, which raises the possibility that this modulator might be involved in the regulation of neuronal functions in the developing brain. The GABAergic system undergoes profound changes during development and is particularly susceptible to modulation by endogenous factors. Therefore, we decided to investigate the impact of Epo on GABAergic transmission in hippocampal neurons developing in vitro. An analysis of miniature IPSCs (mIPSCs) revealed that a long-term treatment with Epo (48 or 72 h) resulted in a major acceleration of the decaying phase of these currents while the amplitude and current frequency remained unchanged. Interestingly, this effect was restricted to the youngest considered age group (6-8 DIV), indicating that Epomediated modulation of mIPSCs depends on the developmental stage of the neurons. We conclude that Epo may exert a modulatory action on GABAergic transmission in developing neural networks. |
Keywords | GABAA receptors, Erythropoietin, Miniature post synaptic current mIPSC, Neuronal culture |
Address and Contact Information | Laboratory of Neuroscience, Department of Biophysics, Wrocław Medical
University, ul. Chałubińskiego 3, 50-367 Wrocław, Poland * Author for correspondence. E-mail: twojtow@biofiz.am.wroc.pl |
DOI: 10.2478/s11658-008-0030-9 Volume 13 (2008) pp 656-666 | |
Title | STRATEGIES FOR THE IDENTIFICATION OF LOCI RESPONSIBLE FOR THE PATHOGENESIS OF MULTIPLE SCLEROSIS |
Authors | Joel N.H. Stern1,3,# and Derin B. Keskin2,3,# |
Abstract | Multiple sclerosis (MS) is a chronic, debilitating disease, which manifests itself by de-myelination of the central nervous system (CNS). MS is predominantly found in Caucasians of European decent and is more prominent in females than males. MS is one of the most prevalent causes of disability of young adults in the world. The exact cause of MS is not known, however genetic susceptibility to MS is linked to the major histocompability complex (MHC). Self reactive CD4+ T cells, specific for CNS antigens, such as myelin basic protein (MBP), myelin oligodendrocyte glycoprotein (MOG) and proteolipid protein (PLP), are detectable in MS patients along with pathogenic autoantibodies specific to these CNS antigens produced by B cells. These observations suggest that MS is an autoimmune disease. Epidemiology of MS along with the analysis of sibling pairs and twins suggest that the multiple genetic factors and their interaction with environment contribute to disease susceptibility. Recent developments and advancements in genetic analysis may aid in accurate determination of genetic risk factors for the development of MS. We review these developments, advances in technology and discuss recent results in this article. |
Keywords | Multiple sclerosis, Experimental allergic encephalomyelitis, Single nucleotide polymorphisms, Genetic linkage studies, Genome wide association studies |
Address and Contact Information | 1Department of Oral Medicine, Infection and Immunity, Harvard School
of Dental Medicine, 190 Longwood Ave, Boston, MA, USA, 2Department of Cancer Immunology and AIDS, Dana Farber Cancer Institute, 44 Binney Street, Boston, MA, USA, 3Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA, USA * Author for correspondence: Joel N.H. Stern and Derin B. Keskin, e-mail addresses: jstern@fas.harvard.edu and derin_keskin@dfci.harvard.edu; tel.: 617-495-5611 # These authors contributed equally to this paper |