ajustandose para funcionar mejor en la membrana ... 7... · pinocitosis fase fluida fusión-fisión...
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Ajustandose para funcionar mejor en la membrana:• Interacciones con secuencias específicas.• Cambios en la composición lipídica.• Forzar cambio en la membrana.
Tuesday, August 18, 2009
Doblándose para funcionar mejor en la membrana:• Cambios en la composición lipídica. In vitro, PtdIns(4,5)P2, PLA.• Influencia de proteínas de membrana: oligomerización, dominios transmembranales cónicos• Citoesqueleto y actividad de motores moleculares.• Andamiaje. BAR, ARF exocitosis, Anfifisina Drosophila.• Inserción de hélices anfipáticas.
Tuesday, August 18, 2009
El Fosfatidil inositol 1,3,5, tri fosfato ftdIns(1,4,5)P3: un lípido poco abundante con efectos cruciales en la función de la membrana:
Tuesday, August 18, 2009
Trafico de membrana:
Tuesday, August 18, 2009
LA MEMBRANA ES UNA ENTIDAD DINÁMICA
Vida media de la Na+,K+/ATPAsa en células epiteliales:sin contactos 24hCon contactos 2h
La aldosterona induce la insersión de canales de agua:
La insulina provoca la insersión de transportadores de glucosa (Glut-1) en adipocitos y miocitos
Tuesday, August 18, 2009
FagocitosisEndocitosisExocitosisPinocitosisFase FluidaFusión-fisión
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The tight junction. Trafficking, signaling, viral receptors, target for pathogens and virulence factors. Polarity (Generate?).TJs: fusion of exoplasmic leaflets.What are the molecular basis for close approximation or fusion between the exoplasmic lipid leaflets?Approximating membranes: a thermodynamically unfavorable, requires proteins. Annexin A2 heterotetramer (A2t), binds lipid bilayer structures through molecular bridging of their external leaflets. Is annexin in tight junction?, and does annexin bridge membranes?.
Annexin
A
Tuesday, August 18, 2009
CAVEOLAE-NOT JUST CRATERS IN THE CELLULAR LANDSCAPEJeoung-Sook Shin and Soman N. Abraham (Duke)Science, 2001,293:1447
HIV bind to glycosphingolipidGalactosyl ceramide receptorsIn caveolae
Parientas de los lipid rafts. Son assembly de glycosphyngolipids and cholesterol, associated with signaling proteins}La endocitosis clásica depende de coated pits que se funden a los lisosomas. Las CAVEOLAE no: NO DEGRADANSU CONTENIDO. Tienen Caveolin, cholesterol y GMI
HIV RSVCHOLERA TOXIN
E. COLI expressing FimHBind to GPI anchored receptorCD48 triggering recruitmentOf caveolae and endocytosis
AEROLYSIN and STREPTOLYSIN are assembled at the caveolaAnd form channels spanning the membrane
TOXOPLASMA induceFormation of vacuoles thatFail to fuse to lysosomes
GOLGI
ER
CAVEOLARMICRODOMAINS
RSV respiratorySyncytial virus
MYCOBACTERIA initiateThe aggregation of distinct hostProteins, which prevents fusionTo lysosomes
Tuesday, August 18, 2009
Microvello
Tuesday, August 18, 2009
Cell theory identifies the cell as the elementary unit from which all living organisms are constructed.
Plasmodesmata connect each plant cell to its neighbours, facilitating the exchange of large molecules and allowing the mass flow of smaller molecules.
Plant cells are neither physically separated nor structurally independent.
Coenocytes and syncytia
In 1853, Thomas Henry Huxley noted a imilar inconsistency between the structure of some tissues and the German cell theory of his day. Cells of multicellular organisms are not anatomically isolated. Are Cells the elementary units of living organisms?.
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Tuesday, August 18, 2009
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Tuesday, August 18, 2009
Tuesday, August 18, 2009
Tuesday, August 18, 2009