DOCSLIB.ORG

Tyrosine Phosphorylation-Dependent Localization of Tmar That Controls Activity of a Major Bacterial Sugar Regulator by Polar Sequestration

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Tyrosine Phosphorylation-Dependent Localization of Tmar That Controls Activity of a Major Bacterial Sugar Regulator by Polar Sequestration Tyrosine phosphorylation-dependent localization of TmaR that controls activity of a major bacterial sugar regulator by polar sequestration Tamar Szokea, Nitsan Albochera,1, Sutharsan Govindarajana,b,1, Anat Nussbaum-Shochata, and Orna Amster-Chodera,2 aDepartment of Microbiology and Molecular Genetics, The Institute for Medical Research Israel–Canada, Faculty of Medicine, The Hebrew University, Jerusalem 91120, Israel; and bDepartment of Biology, SRM University - AP, Amaravati, Andhra Pradesh, 522 502, India Edited by Susan Gottesman, NIH, Bethesda, MD, and approved November 18, 2020 (received for review August 1, 2020) The poles of Escherichia coli cells are emerging as hubs for major via polar cluster formation. Execution of the PTS functions de- sensory systems, but the polar determinants that allocate their pends on a phosphorylation cascade that initiates with EI and components to the pole are largely unknown. Here, we describe HPr—the general PTS proteins—that deliver the phosphate to the discovery of a previously unannotated protein, TmaR, which the PTS sugar permeases, which import and phosphorylate the localizes to the E. coli cell pole when phosphorylated on a tyrosine incoming sugars (10). The PTS proteins also exert different ef- residue. TmaR is shown here to control the subcellular localization fects on non-PTS proteins depending on their phosphorylation and activity of the general PTS protein Enzyme I (EI) by binding on histidine residues, thus modulating the hierarchy in sugar and polar sequestration of EI, thus regulating sugar uptake and utilization (10). The PTS-imported sugars enter glycolysis, whose metabolism. Depletion or overexpression of TmaR results in EI re- product, phosphoenolpyruvate (PEP), phosphorylates EI, mak- lease from the pole or enhanced recruitment to the pole, which ing EI an important link between glycolysis and sugar uptake leads to increasing or decreasing the rate of sugar consumption, (11). We have previously shown that the general PTS proteins respectively. Notably, phosphorylation of TmaR is required to re- localize to the E. coli cell poles (12), although their localization lease EI and enable its activity. Like TmaR, the ability of EI to be depends on yet-unknown factors (13), that during growth EI recruited to the pole depends on phosphorylation of one of its polar clusters form stochastically from preexisting dispersed MICROBIOLOGY tyrosines. In addition to hyperactivity in sugar consumption, the molecules, and that EI clustering negatively correlates with EI absence of TmaR also leads to detrimental effects on the ability of function (14). Still, conclusive proof for polar localization as an cells to survive in mild acidic conditions. Our results suggest that inhibitory mechanism of EI function is lacking and the identity of this survival defect, which is sugar- and EI-dependent, reflects the the factor that captures EI at the pole remained unknown. difficulty of cells lacking TmaR to enter stationary phase. Our Polar clusters offer additional benefits, such as communication study identifies TmaR as the first, to our knowledge, E. coli protein between signal transduction systems in order to generate an reported to localize in a tyrosine-dependent manner and to control optimal response, e.g., the chemotaxis and the PTS system (15), the activity of other proteins by their polar sequestration and or the establishment of cellular asymmetry to coordinate devel- release. opmental programs with cell cycle progression (7). Polar proteins bacterial polarity | tyrosine phosphorylation | PTS system | Significance protein localization | cell pole In recent years, we have learned that bacterial cells have in- he central dogma describes the flow of genetic information tricate spatial organization despite the lack of membrane- Tfrom DNA to RNA to protein. However, for this process to bounded organelles. The endcaps of rod-shaped bacteria, — — be successful, the final product the protein needs to be in the termed poles, are emerging as hubs for sensing and respond- right place and at the right time. The consequences of mis- ing, but the processes involved in positioning macromolecules localization can be harmful to any cell type, let alone to the there are largely unknown. We discovered a protein, TmaR, unicellular bacterial cell, whose survival depends on fast and whose polar localization depends on a phospho-tyrosine efficient response to environmental changes. Hence, protein modification. We show that TmaR controls the activity of EI, localization is an important posttranslational regulatory step. the major regulator of sugar metabolism in most bacteria, by Thus far, most examples of protein targeting were reported in polar sequestration and release. Notably, TmaR is essential for eukaryotic cells, usually in the context of transport from one survival in conditions that Escherichia coli often encounters in organelle to another (1). In recent years, it became evident that nature. Hence, TmaR is a key regulator that connects tyrosine localization of proteins and RNAs to specific subcellular do- phosphorylation, spatial regulation, sugar metabolism, and mains occurs also in prokaryotic cells and is vital for many cel- survival in bacteria. lular processes (2–5). However, the mechanisms underlying macromolecules targeting to specific subcellular domains in Author contributions: T.S., S.G., A.N.-S., and O.A.-C. designed research; T.S., N.A., and bacterial cells, with the exception of membrane and cell division A.N.-S. performed research; T.S. contributed new reagents/analytic tools; T.S. and N.A. proteins, remain largely unknown. analyzed data; T.S., S.G., and O.A.-C. wrote the paper; and O.A.-C. provided advice and The bacterial cell poles are emerging as important domains supervised the research. that accommodate protein and RNA assemblies (5, 6). Pole-lo- The authors declare no competing interest. calized proteins are involved in a wide range of cellular func- This article is a PNAS Direct Submission. tions, including motility, regulation of cell cycle, metabolism, Published under the PNAS license. differentiation, pathogenesis, and secretion (7). Several proteins 1N.A. and S.G. contributed equally to this work. were reported to be kept as inactive at the Escherichia coli cell 2To whom correspondence may be addressed. Email: [email protected]. pole until needed, e.g., MurG (8), and FtsZ (9). The phospho- This article contains supporting information online at https://www.pnas.org/lookup/suppl/ transferase system (PTS), which controls sugar utilization and doi:10.1073/pnas.2016017118/-/DCSupplemental. metabolism in most bacteria, provides an example for regulation Published December 29, 2020. PNAS 2021 Vol. 118 No. 2 e2016017118 https://doi.org/10.1073/pnas.2016017118 | 1of12 Downloaded by guest on October 2, 2021 that recruit other proteins to the poles, thus regulating cell cycle A Phase YFP B Phase mYFP progression, were discovered in some bacteria, e.g., DivIVA in Bacillus subtilis, PopZ and TipN in Caulobacter crescentus, and HubP in Vibrio cholerae (7). In E. coli, the three Min proteins, MinCDE, cooperate to position the cell division site through TmaR-YFP pole-to-pole oscillation (16). mYFP-TmaR In some bacteria, e.g., C. crescentus, specific localization of proteins is linked to their phosphorylation or to the phosphory- C D lation of factors regulating them (17, 18). In most cases, these proteins are members of the two-component systems, which mediate sensing and regulation by phosphorylation on histidine and aspartic acid residues (19), events considered most prevalent Percent of detectable cluster detectable in bacteria. Only in recent years, improved methodologies E OD600 OD600 revealed numerous previously unknown Ser/Thr/Tyr phosphor- (AU) YFP intensity 0.2 0.4 0.6 0.8 1 1.3 1.7 ON TmaR-YFP 55 ylation sites, once thought to be hallmarks of eukaryotes, in 40 The normalized cell length bacterial and archaeal proteins. The degree to which these pu- GroEL 70 55 tative sites are phosphorylated is still unclear and proofs for their F WY72FT Y79 F15Y importance in vivo are just beginning to emerge. Also, the linkage between phosphorylation on Ser/Thr/TyR and localiza- tion of the phosphorylated bacterial proteins remained unknown. In this study, we show that a previously uncharacterized E. coli protein, YeeX, which is prevalent among Gram-negative bacte- ria, clusters at the pole in a tyrosine phosphorylation-dependent manner and recruits the major sugar utilization regulator EI. Y79F,Y72F Y79F,Y72F,Y51F G Fracon of cells with clusters We, therefore, renamed this protein TmaR for targeting of sugar WT metabolism-associated regulator. TmaR and EI are shown to Y79F physically interact and to colocalize. TmaR is necessary for EI Y72F polar clustering, but the opposite is not true. Only phosphory- Y51F lated, TmaR can release EI from the poles, since the diffuse Y79F, Y72F Y79F, Y72F, Y51F nonphosphorylated TmaR binds to EI quite irreversibly. Nota- Y79F bly, tyrosine phosphorylation of EI is also required for its polar Y79F Y79F Y72F H Y79F Y72F I WT Y79FY72F Y51F Y72F Y51F NC localization. We further show that TmaR-mediated EI clustering WT Y79F Y72F Y51F Y72F Y51F 17 inversely correlates with EI-mediated sugar uptake, implying that 40 the polar clusters serve as a reservoir for ready-to-act EI mole- 35 11 cules. Cells lacking TmaR have detrimental effects on cell sur- vival, which is affected by EI and sugar concentration, when Fig. 1. TmaR forms clusters that localize to the pole of E. coli cells in a ty- challenged with mildly acidic conditions that are typical to vari- rosine phosphorylation-dependent manner. (A) Images of cells expressing ous E. coli habitats. Taken together, our study identifies TmaR TmaR-YFP (yellow) from its native promoter and locus in the chromosome. as a spatial regulator of sugar metabolism and bacterial survival. (B) Images of cells expressing TmaR tagged at its N terminus with monomeric YFP (mYFP-TmaR, yellow) from its native promoter and locus in the chro- Results mosome. (C) The fluorescence intensity profile of 50 cells expressing a cluster of TmaR-YFP along the normalized long cell axis.
Load more

Recommended publications
  • Phosphorylation of Chicken Protein Tyrosine Phosphatase 1 by Casein Kinase II in Vitro
    EXPERIMENTAL and MOLECULAR MEDICINE, Vol. 29, No 4, 229-233, December 1997 Phosphorylation of chicken protein tyrosine phosphatase 1 by casein kinase II in vitro Eun Joo Jung,1 Kee Ryeon Kang1 and Introduction Yoon-Se Kang1,2 The phosphorylation of protein tyrosine residues is an early event in signal transduction initiated by binding of 1 Department of Biochemistry and Gyeongsang Institute of Cancer growth factors and hormones to their cognate receptors Research, College of Medicine, Gyeongsang National University, and it leads to regulation of cellular activities which include Chinju 660-280, Korea proliferation, differentiation, and also malignant transfor- 2 Corresponding author mation of cells (Hunter, 1989; Ullirich and Schlessinger, Accepted 17 November 1997 1990; Cantley et al., 1991). Under normal conditions, the level of tyrosine phosphorylation within a cell is determined by a balance between the actions of protein tyrosine Abbreviations: CPTP, chicken protein tyrosine phosphatase; HPTP1B, human placenta kinases (PTKs) and protein tyrosine phosphatases (PTPs) protein tyrosine phosphatase 1B; CKII, casein kinase II; MAP kinase, mitogen-activated (Hunter, 1989; Fischer et al., 1991; Trowbridge, 1991). protein kinase; GST, glutathione S-transferase; pNPP, p-nitrophenyl phosphate; EGF, PTPs do not simply reverse the action of tyrosine kinases, epidermal growth factor but rather, PTP itself may play a central role in cellular regulation. PTPs are generally classified as transmem- brane (receptor-type) and nontransmembrane (nonrecep- tor-type) enzymes based on the presence or absence of extracellular and transmembrane portions of their predicted sequence (Fischer et al., 1991). Because the activity of Abstract tyrosine kinase can be controlled by phosphorylation, it has been postulated that PTP activity may be regulated The phosphorylation and dephosphorylation of by phosphorylation as well.
    [Show full text]
  • Mechanism of Insulin Receptor Kinase Inhibition in Non-Insulin- Dependent Diabetes Mellitus Patients
    Mechanism of insulin receptor kinase inhibition in non-insulin- dependent diabetes mellitus patients. Phosphorylation of serine 1327 or threonine 1348 is unaltered. M Kellerer, … , K Siddle, H U Häring J Clin Invest. 1995;96(1):6-11. https://doi.org/10.1172/JCI118073. Research Article The tyrosine kinase activity of insulin receptor isolated from the skeletal muscle of NIDDM patients has previously been found to be decreased compared with the activity of receptor from nondiabetic subjects but the mechanism underlying this defect is unknown. Phosphorylation of receptor serine/threonine residues has been proposed to exert an inhibitory influence on receptor tyrosine kinase activity and Ser 1327 and Thr 1348 have been identified as specific sites of phosphorylation in the insulin receptor COOH terminal domain. To address the potential negative regulatory role of phosphorylation of these residues in vivo, we assessed the extent of phosphorylation of each site in insulin receptor isolated from the skeletal muscle of 12 NIDDM patients and 13 nondiabetic, control subjects. Phosphorylation of Ser 1327 and Thr 1348 was determined using antibodies that specifically recognize insulin receptor phosphorylated at these sites. In addition, a phosphotyrosine-specific antibody was used to monitor receptor tyrosine phosphorylation. The extent of insulin-induced tyrosine autophosphorylation was decreased in receptor isolated from diabetic versus nondiabetic muscle, thus confirming earlier reports. In contrast, there was no significant difference in the extent of phosphorylation of either Ser 1327 or Thr 1348 in receptor isolated from diabetic or nondiabetic muscle as assessed by immunoprecipitation (Ser 1327: 5.6 +/- 1.6% diabetics vs. 4.7 +/- 2.0% control; Thr 1348: 3.8 +/- 1.0% diabetics vs.
    [Show full text]
  • Phosphorylation of Protein 4.1 on Tyrosine-418 Modulates Its Function
    Proc. Nati. Acad. Sci. USA Vol. 88, pp. 5222-5226, June 1991 Biochemistry Phosphorylation of protein 4.1 on tyrosine-418 modulates its function in vitro (epidermal growth factor receptor/spectrin/actin assembly) GOSUKONDA SUBRAHMANYAM*, PAUL J. BERTICStt, AND RICHARD A. ANDERSON**§ Department of *Pharmacology and tPhysiological Chemistry, and the tCell and Molecular Biology Program, University of Wisconsin Medical School, 1300 University Avenue, Madison, WI 53706 Communicated by Vincent T. Marchesi, March IS, 1991 ABSTRACT Protein 4.1 was initially characterized as a actin/protein 4.1 complex (12). However, phosphorylation of protein that regulates cytoskeletal assembly in erythrocytes. protein 4.1 by protein kinase C also reduces protein 4.1 However, recent studies have shown that protein 4.1 is ubiq- binding to band 3 but not to glycophorin, while phosphory- uitous in mammalian cells. Here, we show that protein 4.1 is lation by cAMP-dependent kinase does not affect membrane phosphorylated on tyrosine by the epidermal growth factor interactions (12). These results suggest that protein 4.1 is receptor (EGFR) tyrosine kinase. The phosphorylation site has phosphorylated at multiple sites by different protein kinases, been localized to the 8-kDa domain, which has one tyrosine, and each phosphorylation event selectively modulates pro- tyrosine-418. The 8-kDa region is required for the assembly of tein 4.1 function. The phosphorylation sites by cAMP- the spectrin/actin complex, and phosphorylation by EGFR dependent protein kinase and protein kinase C are in the reduced the ability ofprotein 4.1 to promote the assembly ofthe 8-kDa and 16-kDa domains (10).
    [Show full text]
  • Tyrosine Kinases Play a Permissive Role in Glucose-Induced Insulin Secretion from Adult Rat Islets
    19 Tyrosine kinases play a permissive role in glucose-induced insulin secretion from adult rat islets S J Persaud, T E Harris, C J Burns and P M Jones Cellular and Molecular Endocrinology Group, Biomedical Sciences Division, King’s College London, Campden Hill Road, London W8 7AH, UK (Requests for offprints should be addressed to S J Persaud) ABSTRACT The role(s) played by protein tyrosine kinases (TA47) inhibited islet tyrosine kinase activities (PTKs) in the regulation of insulin secretion from and glucose-, 4á ketoisocaproic acid (KIC)- and pancreatic â cells is not clear. We have examined the sulphonylurea-stimulated insulin release, without effects of glucose, the major physiological insulin affecting glucose metabolism. GS and TA47 also secretagogue, on the tyrosine phosphorylation state inhibited protein serine/threonine kinase activities of islet proteins, and assessed â cell insulin secretory to a limited extent, but had no effect on Ca2+, cyclic responses in the presence of PTK inhibitors. Under AMP- or phorbol myristate acetate (PMA)-induced basal conditions islets contained many proteins insulin secretion from electrically permeabilised phosphorylated on tyrosine residues, and glucose islets. These results suggest that PTK inhibitors (20 mM; 5–15 min) was without demonstrable effect exert their inhibitory effects on insulin secretion on the pattern of tyrosine phosphorylation, in either proximal to Ca2+ entry and it is proposed that the absence or presence of the protein tyrosine they act at the site of the voltage-dependent Ca2+ phosphatase (PTP) inhibitor, sodium pervanadate channel which regulates Ca2+ influx into â cells (PV). PV alone (100 µM) increased tyrosine following nutrient- and sulphonylurea-induced phosphorylation of several islet proteins.
    [Show full text]
  • SNT, a Differentiation-Specific Target of Neurotrophic Factor-Induced Tyrosine Kinase Activity in Neurons and PC12 Cells STUART J
    MOLECULAR AND CELLULAR BIOLOGY, Apr. 1993, p. 2203-2213 Vol. 13, No. 4 0270-7306/93/042203-11$02.00/0 Copyright ) 1993, American Society for Microbiology SNT, a Differentiation-Specific Target of Neurotrophic Factor-Induced Tyrosine Kinase Activity in Neurons and PC12 Cells STUART J. RABIN, VAUGHN CLEGHON, ANtD DAVID R. KAPLAN* Eukaryotic Signal Transduction Group, Molecular Mechanisms of Carcinogenesis Laboratory, ABL-Basic Research Program, National Cancer Institute-Frederick Cancer Research and Development Center, P.O. Box B, Frederick, Maryland 21702-1201 Received 23 October 1992/Returned for modification 26 November 1992/Accepted 26 January 1993 To elucidate the signal transduction mechanisms used by ligands that induce differentiation and the cessation of cell division, we utilized p13 uc1agarose, a reagent that binds p34C2/cdk2 By using thi re t identified a 78- to 90-kDa species in PC12 pheochromocytoma cells that is rapidly phosphorylated on tyrosine following treatment with the differentiation factors nerve growth factor (NGF) and fibroblast growth factor but not by the mitogens epidermal growth factor or insulin. This species, called SNT (suc-associated neurotrophic factor-induced tyrosine-phosphorylated target), was also phosphorylated on tyrosine in primary rat cortical neurons treated with the neurotrophic factors neurotrophin-3, brain-derived neurotrophic factor, and fibroblast growth factor but not in those treated with epidermal growth factor. In neuronal and fibroblast cells, where NGF can also act as a mitogen, SNT was tyrosine phosphorylated to a much greater extent during NGF-induced differentiation than during NGF-induced proliferation. SNT was phosphorylated in vitro on serine, threonine, and tyrosine in pl3sucl-agarose precipitates from NGF-treated PC12 cells, indicating that this protein may be a substrate of kinase activities associated with p13suc1-p34cdc21cdk2 complexes.
    [Show full text]
  • Tyrosine Phosphorylation and Activationof STAT5, STAT3
    Proc. Natl. Acad. Sci. USA Vol. 92, pp. 8705-8709, September 1995 Immunology Tyrosine phosphorylation and activation of STAT5, STAT3, and Janus kinases by interleukins 2 and 15 JAMES A. JOHNSTON*tt, CHRIS M. BACON*t§, DAVID S. FINBLOOMI, ROBERT C. REES§, DAVID KAPLANII, KYO SHIBUYAII, JOHN R. ORTALDO**, SANJAY GUPTAtt, YI QING CHEN*, JUDY D. GIRItt, AND JOHN J. O'SHEA* *Lymphocyte Cell Biology Section, Arthritis and Rheumatism Branch, National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, MD 20892; IDivision of Cytokine Biology, Center for Biologics Evaluation and Research, Food and Drug Administration, Bethesda, MD; **Laboratory of Experimental Immunology, Biological Response Modifiers Program, Division of Cancer Treatment and I1Advanced BioScience Laboratories, National Cancer Institute-Frederick Cancer Research and Development Center, Frederick, MD 21702-1201; ttlmmunex Research and Development Corporation, Seattle, WA 98101; ttDepartment of Medicine, College of Physicians and Surgeons, Columbia University, New York, NY 10032; and §Institute for Cancer Studies, University of Sheffield Medical School, Sheffield, South Yorkshire, S10 2RX, United Kingdom Communicated by Henry Metzger, National Institutes of Health, Bethesda, MD, June 15, 1995 (received for review March 23, 1995) ABSTRACT The cytokines interleukin 2 (IL-2) and IL-15 important to examine whether IL-15 might also activate JAK3 have similar biological effects on T cells and bind common and JAK1. hematopoietin receptor subunits. Pathways that involve Janus Studies of the mechanism by which hematopoietin receptors kinases (JAKs) and signal transducers and activators of activate gene transcription indicate that STAT proteins be- transcription (STATs) have been shown to be important for come rapidly tyrosine-phosphorylated in the receptor complex hematopoietin receptor signaling.
    [Show full text]
  • 257.Full.Pdf
    TNF-α Induces Tyrosine Phosphorylation and Recruitment of the Src Homology Protein-Tyrosine Phosphatase 2 to the gp130 Signal-Transducing Subunit of the IL-6 This information is current as Receptor Complex of October 1, 2021. Johannes G. Bode, Jens Schweigart, Jan Kehrmann, Christian Ehlting, Fred Schaper, Peter C. Heinrich and Dieter Häussinger J Immunol 2003; 171:257-266; ; Downloaded from doi: 10.4049/jimmunol.171.1.257 http://www.jimmunol.org/content/171/1/257 References This article cites 54 articles, 32 of which you can access for free at: http://www.jimmunol.org/ http://www.jimmunol.org/content/171/1/257.full#ref-list-1 Why The JI? Submit online. • Rapid Reviews! 30 days* from submission to initial decision • No Triage! Every submission reviewed by practicing scientists by guest on October 1, 2021 • Fast Publication! 4 weeks from acceptance to publication *average Subscription Information about subscribing to The Journal of Immunology is online at: http://jimmunol.org/subscription Permissions Submit copyright permission requests at: http://www.aai.org/About/Publications/JI/copyright.html Email Alerts Receive free email-alerts when new articles cite this article. Sign up at: http://jimmunol.org/alerts The Journal of Immunology is published twice each month by The American Association of Immunologists, Inc., 1451 Rockville Pike, Suite 650, Rockville, MD 20852 Copyright © 2003 by The American Association of Immunologists All rights reserved. Print ISSN: 0022-1767 Online ISSN: 1550-6606. The Journal of Immunology TNF-␣ Induces Tyrosine Phosphorylation and Recruitment of the Src Homology Protein-Tyrosine Phosphatase 2 to the gp130 Signal-Transducing Subunit of the IL-6 Receptor Complex1 Johannes G.
    [Show full text]
  • Tyrosine Phosphorylation of Protein Kinase Complex BAK1/BIK1 Mediates Arabidopsis Innate Immunity
    Tyrosine phosphorylation of protein kinase complex BAK1/BIK1 mediates Arabidopsis innate immunity Wenwei Lina,1,BoLia,b,c,1, Dongping Lub, Sixue Chend, Ning Zhud, Ping Heb, and Libo Shana,2 Departments of aPlant Pathology and Microbiology and bBiochemistry and Biophysics, Institute for Plant Genomics and Biotechnology, Texas A&M University, College Station, TX 77843; cProvincial Key Laboratory of Plant Pathology of Hubei Province, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, Hubei 430070, People’s Republic of China; and dDepartment of Biology, Genetics Institute, Plant Molecular and Cellular Biology Program, University of Florida, Gainesville, FL 32610 Edited by Frederick M. Ausubel, Harvard Medical School; Massachusetts General Hospital, Boston, MA, and approved January 13, 2014 (received for review October 7, 2013) The sessile plants have evolved a large number of receptor-like BAK1 in transducing flagellin signaling (10). BR-signaling kinase kinases (RLKs) and receptor-like cytoplasmic kinases (RLCKs) to 1 (BSK1), another RLCK and originally identified as a substrate modulate diverse biological processes, including plant innate of the brassinosteroid receptor BRI1 (BR insensitive 1), asso- immunity. Phosphorylation of the RLK/RLCK complex constitutes ciates with FLS2 and positively regulates PTI signaling (12). an essential step to initiate immune signaling. Two Arabidopsis Stomatal cytokinesis-defective 1 (SCD1), an FLS2-associated plasma membrane-resident RLKs, flagellin-sensing 2 and brassi- protein identified from proteomics analysis, is required for cer- nosteroid insensitive 1-associated kinase 1 (BAK1), interact with tain aspects of flg22-mediated responses (13). Activation of RLCK Botrytis-induced kinase 1 (BIK1) to initiate plant immune MAP kinases (MAPKs) and calcium-dependent protein kinases responses to bacterial flagellin.
    [Show full text]
  • Mechanism for Inhibition of Phagocytosis R in Human
    HIV-1 Down-Modulates γ Signaling Chain of Fc γR in Human Macrophages: A Possible Mechanism for Inhibition of Phagocytosis This information is current as Katherine Kedzierska, Philip Ellery, Johnson Mak, Sharon R. of September 25, 2021. Lewin, Suzanne M. Crowe and Anthony Jaworowski J Immunol 2002; 168:2895-2903; ; doi: 10.4049/jimmunol.168.6.2895 http://www.jimmunol.org/content/168/6/2895 Downloaded from References This article cites 63 articles, 36 of which you can access for free at: http://www.jimmunol.org/content/168/6/2895.full#ref-list-1 http://www.jimmunol.org/ Why The JI? Submit online. • Rapid Reviews! 30 days* from submission to initial decision • No Triage! Every submission reviewed by practicing scientists • Fast Publication! 4 weeks from acceptance to publication by guest on September 25, 2021 *average Subscription Information about subscribing to The Journal of Immunology is online at: http://jimmunol.org/subscription Permissions Submit copyright permission requests at: http://www.aai.org/About/Publications/JI/copyright.html Email Alerts Receive free email-alerts when new articles cite this article. Sign up at: http://jimmunol.org/alerts The Journal of Immunology is published twice each month by The American Association of Immunologists, Inc., 1451 Rockville Pike, Suite 650, Rockville, MD 20852 Copyright © 2002 by The American Association of Immunologists All rights reserved. Print ISSN: 0022-1767 Online ISSN: 1550-6606. HIV-1 Down-Modulates ␥ Signaling Chain of Fc␥R in Human Macrophages: A Possible Mechanism for Inhibition of Phagocytosis1 Katherine Kedzierska,*‡ Philip Ellery,* Johnson Mak,*§ Sharon R. Lewin,¶ Suzanne M. Crowe,2*†‡ and Anthony Jaworowski2,3*† HIV-1 infection impairs a number of macrophage effector functions, thereby contributing to development of opportunistic infec- tions and the pathogenesis of AIDS.
    [Show full text]
  • The Tyrosine Kinase and Mitogen-Activated Protein Kinase Pathways Mediate Multiple Effects of Estrogen in Hippocampus
    The tyrosine kinase and mitogen-activated protein kinase pathways mediate multiple effects of estrogen in hippocampus Ruifen Bi*, Greg Broutman*, Mike R. Foy†, Richard F. Thompson*, and Michel Baudry*‡ *Neuroscience Program, University of Southern California, Los Angeles, CA 90089-2520; and †Department of Psychology, Loyola Marymount University, Los Angeles, CA 90045 Contributed by Richard F. Thompson, January 27, 2000 Estrogen replacement therapy in women is associated with Materials and Methods improvement of cognitive deficits and reduced incidence of Preparation of Hippocampal Slice Cultures. Transverse hippocampal Alzheimer’s disease. The present study indicates that estrogen is slice cultures were prepared from 7- to 10-day-old rat pups neuroprotective against N-methyl-D-aspartate (NMDA)- and kain- ͞ according to standard techniques (25). Briefly, hippocampi were ate-mediated neurotoxicity, an effect mediated by tyrosine kinase dissected and sectioned transversely at 400 ␮m by using a mitogen-activated protein kinase (MAPK) pathways. Estrogen also McIlwain tissue chopper (Westbury, NY) in a cutting medium stimulates tyrosine phosphorylation of NMDA receptors via an src consisting of MEM (with Earle’s salts; GIBCO), 25 mM Hepes, tyrosine kinase͞MAPK pathway. Finally, estrogen-mediated en- 10 mM Tris, 10 mM glucose, and 3 mM MgCl (pH 7.2). hancement of long-term potentiation in hippocampal slices is 2 Hippocampal sections were then placed onto membrane inserts mediated by activation of an src tyrosine kinase pathway. Thus, (Millipore) in 6-well culture trays with 1 ml of growth medium estrogen, by activating an src tyrosine kinase and the extracellular ͞ ͞ ͞ [MEM with Hanks’ salts (GIBCO) 20% (vol/vol) horse serum 3 signal-related protein kinase MAPK signaling pathway, both en- ͞ ͞ ͞ ͞ mM glutamine 25 mM Hepes 5 mM NaHCO3 25 mM glucose hances NMDA receptor function and long-term potentiation and ͞ ͞ ͞ 0.5 mM ascorbate 2 mM CaCl2 2.5 mM MgCl2 0.5 mg/liter retains neuroprotective properties against excitotoxicity.
    [Show full text]
  • C-Terminal Tyrosine Phosphorylation of the Viral Matrix Protein Is a Key Regulator
    Cell, Vol. 80, 379-388, February 10, 1995, Copyright © 1995 by Cell Press HIV-1 Infection of Nondividing Cells: C-Terminal Tyrosine Phosphorylation of the Viral Matrix Protein Is a Key Regulator Philippe Gallay, Simon Swingler, Christopher Aiken, et al., 1992) that closely resembles the prototypic SV40 and Didier Trono large T antigen NLS (Kalderon et al., 1984). A peptide Infectious Disease Laboratory based on the MA NLS acts as a nuclear targeting se- The Salk Institute for Biological Studies quence when coupled to a heterologous protein in vitro 10010 North Torrey Pines Road (Bukrinsky et al., 1993a). In cells acutely infected with H IV-l, La Jolla, California 92037 MA was detected in fractions containing partially purified HIV-1 preintegration complexes (Bukrinsky et al., 1993b), as well as in the nucleus (Sharova and Bukrinskaya, 1991). Summary In the absence of a functional vpr gene, the critical role of the MA NLS is further revealed: vpr-MA-NLS double The HIV-1 matrix (MA) protei n contains two subcellular mutant viruses show a defect in nuclear import and, as a localization signals with opposing effects. A myristoy- result, have an impaired ability to infect nondividing cells lated N-terminus governs particle assembly at the such as macrophages (Bukrinsky et al., 1993a; Heinzinger plasma membrane, and a nucleophilic motif facilitates et al., 1994; von Schwedler et al., 1994). import of the viral preintegration complex into the nu- In addition to fulfilling this critical function at an early cleus of nondividing cells. Here, we show that myris- step of the infection process, MA also plays an essential toylation acts as the MA dominant targeting signal in role in virus morphogenesis.
    [Show full text]
  • The Role of Tyrosine Phosphorylation in Regulation of Signal Transduction Pathways in Unicellular Eukaryotes
    Curr. Issues Mol. Biol. 8: 27–50. Online journal at www.cimb.org The Role of Tyrosine Phosphorylation in Regulation of Signal Transduction Pathways in Unicellular Eukaryotes Irina V. Schemarova transducer and activator of transcription) proteins located in the cytoplasm. This transmission is also provided by Sechenov Institute of Evolutionary Physiology and the SH2 domain contacts responsible for coupling of Biochemistry, Russian Academy of Sciences, St. phosphotyrosine-containing proteins (Darnell, 1997). Petersburg 194223, Russia The structural-functional organization of Ras-MAPK and STAT signaling pathways in vertebrate cells has Abstract been intensively studied for more than 20 years. By The review summarizes for the frst time the current the present time an extensive experimental material concepts of the role of tyrosine phosphorylation in has been accumulated, which allows judging about the regulation of signal transduction pathways in unicellular events in cells of the higher eukaryotes at each stage of eukaryotes. Evolutionary concepts are developed about transmission of proliferative signal. Much less is known the origin of protein tyrosine kinases (PTK)-signaling. about mechanisms of transmission of growth signals in cells of primitive eukaryotes. There are practically no data Introduction in the literature about the existence of their STAT and Ras- At the end of the last century, in mammalian cells a multi- MAPK pathways of the signal transmission; meanwhile, it cascade pathway was discovered to be responsible for is obvious that RTKs exist not only in mammals, but in transmission of proliferative signals into genome. The multicellular invertebrates, including the most primitive key role in the signal transmission through this pathway — sponges and coelenterates (Schartl, Barnekow, 1982; is played by processes of phosphorylation of protein Schartl et al., 1989; Kruse et al., 1997).
    [Show full text]