Legionella pneumophila: Diferenzas entre revisións

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Miguelferig (conversa | contribucións)
Miguelferig (conversa | contribucións)
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In order for ''Legionella'' to survive within [[macrophages]] and [[protozoa]] it must create a specialized compartment known as the ''Legionella'' containing vacuole or LCV. Through the action of the Dot/Icm secretion system, the bacteria is able to prevent degradation by the normal endosomal trafficking pathway and instead replicates. Shortly after internalization, the bacteria specifically recruits [[endoplasmic reticulum]]-derived vesicles and [[mitrochondria]] to the LCV while preventing the recruitment of endosomal markers such as [[Rab5]] and [[Rab7]]. Formation and maintanience of the vacuole are crucial for pathogensis, bacteria lacking the Dot/Icm secretion system are non-pathogenic and cannot replicate within cells while deletion of the Dot/Icm effector SdhA results in destabilization of the vacuolar membrane and no bacterial replication.<ref>[http://www.ncbi.nlm.nih.gov/pubmed/23649096]</ref><ref>[http://www.ncbi.nlm.nih.gov/pubmed/22308473?dopt=Citation]</ref>
 
== AdquisiciónObtención de nutrientes ==
 
Unha vez que está dentro da célula [`hóspede]], ''Legionella'' precisa nutrientes para crecer e reproducirse. Dentro dos vacúolos a dispoñibilidade de nutrientes é baixa, a gran demanda de [[aminoácido]]s da bacteria non está cuberta co transporte dos aminoácidos libres que se encontran no [[citoplasma]] do hóspede. Para mellorar a dispoñibilidade de aminoácidos, o parasito promove o mecanismo da degradación [[proteasoma|proteasómica]] do hóspede. Isto xera un exceso de aminoácidos libres no citoplasma das células infectadas por ''L. pneumophila'', que pode utilizarse para a proliferación intravacuolar do parasito.
Once inside the host-cell, ''Legionella'' needs nutrients to grow and reproduce. Inside the vacuole, nutrient availability is low, the high demand of [[amino acids]] is not covered by the transport of free amino acids found in the host cytoplasm. In order to improve the availability of amino acids, the parasite promotes the host mechanisms of proteasomal degradation. This generates an excess of free amino acids in the cytoplasm of L. pneumophila-infected cells that can be used for intra-vacuolar proliferation of the parasite.
 
ToPara obtainobter aminoaminoácidos acids,''L. Legionellapneumophila'' pneumophilautiliza useso theefector AnkB bona fide F-Box effector, whicho iscal farnesylatedé by[[farnesilación|farnesilado]] thepola activityactividade ofde threetres hostencimas enzymesdo localizedhóspede inlocalizados thena membranemembrana ofdos thevacúolos LCVque (conteñen a ''Legionella'', containingque vacuole)son: [[farnesyltransferase]] (FTase), Ras-convertingencima protease enzyme-1 proteaseconvertidora de Ras (RCE1), ande isoprenyla cysteineisoprenil carboxylcisteína methylcarboxil metil transferase (IcmT). A [[Farnesylationfarnesilación]] allowspermite que AnkB to get anchored intose theancore cytoplasmicno sidelado ofcitoplásmico thedo vacuolevacúolo.
 
Unha vez que AnkB está ancorado na membrana do vacúolo, este interacciona co complexo SCF1 ubiquitina ligase e funciona como unha plataforma para o atraque no vacúolo de proteínas poliubiquitinadas ligadas a K48.
Once AnkB is anchored into the LCV membrane, it interacts with the SCF1 ubiquitin ligase complex and functions as a platform for the docking of K48-linked polyubiquitinated proteins to the LCV.
TheA poliubiquitinación ligada a K48-linked polyubiquitinationé unha marca ispara a markerdegradación for[[proteasoma]]l proteasomalque degradationlibera thatpéptidos releasesde 2 toa 24 aminoaminoácidos acid-longde peptideslongo, whichque areson quicklyrapidamente degradeddegradados toa aminoaminoácidos acidspor by variousvarias oligopeptidases ande aminopeptidases present inpresentes theno cytoplasmcitoplasma.
Os aminoácidos impórtanse ao interior dos vacúolos que conteñen lexionela por medio de varios transportadores de aminoácidos como o SLC1A5 (transportador de aminoácidos neutro).
Amino acids are imported into the LCV through various amino acid transporters such as the SLC1A5 (Neutral amino acid transporter).
Os aminoácidos son a fonte primaria de carbono e enerxía para ''L. pneumophila'', a cal para aproveitalos ten unhas 12 clases ode transportadores ABC, aminoácido permeases, e moitas [[protease]]s. Os aminoácidos importados utilízaos ''L. pneumophila'' para xerar enerxía a través do [[ciclo do ácido cítrico]] e como fontes de carbono e nitróxeno.
The amino acids are the primary carbon and energy source of L. Pneumophila, that have almost 12 classes of ABC transporters, amino acid permeases, and many proteases, to exploit it. The imported amino acids are utilized by L. pneumophila to generate energy through the TCA cycle ([[Krebs cycle]]) and as sources of carbon and nitrogen.
 
Porén, a promoción da degradación proteasomal para a obtención de aminoácidos pode non ser a única estratexia de [[virulencia]] para obter fontes de carbono e enerxía do hóspede. Os encimas degradativos segregados polo sistema de tipo II poden proporcionar unha estratexia adicional para xerar fontes de carbono e enerxía.
However, promotion of proteasomal degradation for the obtention of amino acids may not be the only [[virulence]] strategy to obtain carbon and energy sources from the host. Type II–secreted degradative enzymes may provide an additional strategy to generate carbon and energy sources.
 
==Xenómica==