|
[[Ficheiro:Signal transduction pathways.svg|500px|miniatura|dereita|[[Transdución de sinais]] envolvida na [[apoptose]].]]
CytochromeO citocromo ''c'' isé alsotamén anun intermediateintermediario inna [[apoptosisapoptose]], aque controlledé formunha offorma cellcontrolada deathde usedmorte tocelular killutilizada cellspara inmatar thecélulas processdurante ofo developmentproceso ordo indesenvolvemento responseou toen infectionresposta ora DNAunha damageinfección ou danos no [[ADN]].<ref name="pmid8689682">{{cite journal | author = Liu X, Kim CN, Yang J, Jemmerson R, Wang X | title = Induction of apoptotic program in cell-free extracts: requirement for dATP and cytochrome c | journal = Cell | volume = 86 | issue = 1 | pages = 147–57 |date=July 1996 | pmid = 8689682 | doi = 10.1016/S0092-8674(00)80085-9 }}</ref>
O citocromo ''c'' únese á [[cardiolipina]] na membrana mitocondrial interna, o que a acora á membrana e evita que se libere fóra da mitocondria e inicie a apoptose. Aínda que a atracción inicial entre a cardiolipina e o citocromo '''c''' é electrostática debido á carga moi positiva sobre o citocromo ''c'', a interacción final é hidrofóbica, cando unha cola hidrofóbica da cardiolipina se insire na porción hidrofóbica do citocromo ''c''.
Cytochrome ''c'' binds to [[cardiolipin]] in the inner mitochondrial membrane, thus anchoring its presence and keeping it from releasing out of the mitochondria and initiating apoptosis. While the initial attraction between cardiolipin and cytochrome c is electrostatic due to the extreme positive charge on cytochrome c, the final interaction is hydrophobic, where a hydrophobic tail from cardiolipin inserts itself into the hydrophobic portion of cytochrome c.
DuringDurante thea earlyfase phaseinicial ofda apoptosisapoptose, mitochondrialestá ROSestimulada productiona isprodución stimulated,mitocondrial andde cardiolipin[[especies isreactivas oxidizeddo byoxíxeno]]on, e a peroxidasecardiolipina functionoxídase ofpor theunha cardiolipin–cytochromefuncion cperoxidase complex.que Theten hemoproteino iscomplexo thencardiolipina–citocromo detachedc. fromA the[[hemoproteína]] mitochondrialsepárase innerdespois membraneda andmembrana canmitocondrial beinterna extrudede intopode thepasar ao citoplasma soluble cytoplasma throughtravés poresde inporos thena outermembrana membraneexterna. <ref name="PMID16408030">{{cite journal |author=Orrenius S, Zhivotovsky B |title=Cardiolipin oxidation sets cytochrome c free |journal=[[Nat. Chem. Biol.]] |volume=1 |issue=4 |pages=188–9 |date=September 2005 |pmid=16408030 |doi=10.1038/nchembio0905-188}}</ref>
TheA sustainedelevación elevationsostida innos niveis de [[calciumcalcio]] levelsprecee precedesa liberación do cytcitocromo ''c'' releaseda from the mitochondriamitocondria. TheA releaseliberación ofde smallpequenas amountscantidades ofde cytcitocromo ''c'' leadscausa tounha aninteracción interaction with theco [[Inositolreceptor triphosphatedo inositol trifosfato|receptor| IP3 receptor]] (IP3R) on theno [[endoplasmicretículo reticulumendoplasmático]] (ER), causingcausando ERa calciumliberación de calcio polo releaseretículo endoplasmático. TheO overallincremento increaseglobal inde calciumcalcio triggersactiva aunha massivemasiva releaseliberación ofde cytcitocromo ''c'', whicho thencal actsdespois inactúa theno positivebucle feedbackde loop[[retroalimentación]] topositivo maintainque ERmantén calciuma releaseliberación de calcio do retículo endoplasmático a throughtravés thedos IP3Rs.<ref name="pmid14608362">{{cite journal | author = Boehning D, Patterson RL, Sedaghat L, Glebova NO, Kurosaki T, Snyder SH | title = Cytochrome c binds to inositol (1,4,5) trisphosphate receptors, amplifying calcium-dependent apoptosis | journal = Nat. Cell Biol. | volume = 5 | issue = 12 | pages = 1051–61 |date=December 2003 | pmid = 14608362 | doi = 10.1038/ncb1063 }}</ref> ThisIsto explainsexplica howcomo thea ERliberación calciumde releasecalcio canpolo reachretículo cytotoxicendoplasmático levels.pode atinxir Thisniveis [[citotoxicidade|citotóxicos]]. releaseEsta ofliberación cytochromede citocromo ''c'' iná turnsúa activatesvez activa a [[caspase 9]], aque cysteineé unhs cisteína [[protease]]. A Caspasecaspase 9 canpode thendespois gocontinuar, onactivando to activatea [[caspase 3]] ande a [[caspase 7]], whichas arecales responsibleson forresponsables destroyingde thedestruír a cellcélula fromdesde withindentro.
== Localización extramitocondrial ==
|
