{"id":5723,"date":"2012-05-21T09:45:34","date_gmt":"2012-05-21T07:45:34","guid":{"rendered":"https:\/\/ellipse.prbb.org\/?p=5723"},"modified":"2024-01-19T12:35:06","modified_gmt":"2024-01-19T11:35:06","slug":"transduccio-de-senyal-com-funciona-la-xarxa-de-comunicacio-cel%c2%b7lular","status":"publish","type":"post","link":"https:\/\/ellipse.prbb.org\/ca\/transduccio-de-senyal-com-funciona-la-xarxa-de-comunicacio-cel%c2%b7lular\/","title":{"rendered":"Transducci\u00f3 de senyal: com funciona la xarxa de comunicaci\u00f3 cel\u00b7lular"},"content":{"rendered":"<p>La <strong>transducci\u00f3 de senyals<\/strong> <strong>a la c\u00e8l\u00b7lula<\/strong>, descoberta als anys setanta per Martin Rodbell i per la qual va rebre el premi Nobel el 1994, \u00e9s encara un tema d\u2019intensa recerca. Amb l\u2019objectiu de respondre als est\u00edmuls mediambientals, els organismes vius han desenvolupat una \u00e0mplia varietat de processos per <strong>transmetre senyals des de l\u2019exterior a l\u2019interior <\/strong>i produir una <strong>resposta cel\u00b7lular adequada<\/strong>. Defectes en aquestes vies moleculars poden provocar problemes com la <strong>diabetis<\/strong>, el <strong>c\u00e0ncer<\/strong> o <strong>malalties psic\u00f2tiques<\/strong>.<\/p>\n<p>Hi ha dos passos principals en aquest proc\u00e9s:<\/p>\n<ol>\n<li>Primer, una <strong>mol\u00e8cula de senyal <\/strong>(o<strong> lligand<\/strong>) necessita activar un <strong>receptor<\/strong> <strong>espec\u00edfic<\/strong> situat a la membrana o al citoplasma de la c\u00e8l\u00b7lula. La uni\u00f3 lligand-receptor \u00e9s molt espec\u00edfica; es reconeixen com una clau i un pany.<\/li>\n<li>Despr\u00e9s, un <strong>missatger<\/strong>&nbsp;<strong>secundari<\/strong> transmet el senyal als <strong>enzims<\/strong> o <strong>activadors gen\u00e8tics<\/strong>.<\/li>\n<\/ol>\n<p>En cada pas, el senyal pot ser <strong>amplificat<\/strong> i provocar respostes diferents. La major part dels receptors dels senyals canvien de forma una vegada s\u2019uneixen amb els seus lligands. Aix\u00f2 pot exposar un domini enzim\u00e0tic o obrir un canal d\u2019ions. L\u2019activitat enzim\u00e0tica, com ara la <strong>fosforilaci\u00f3<\/strong>, inicia una allau de senyals, modificant o alliberant mol\u00e8cules de missatgers secundaris.<\/p>\n<p><strong>Les hormones esteroides<\/strong> com la cortisona, la testosterona o la progesterona s\u00f3n <strong>solubles<\/strong> en els l\u00edpids i, per tant, poden passar a trav\u00e9s de les membranes a l\u2019interior de la c\u00e8l\u00b7lula sense necessitat d&#8217;un receptor extern. All\u00ed, un receptor intracel\u00b7lular, i tamb\u00e9 espec\u00edfic, s\u2019hi uneix i permet al conjunt moure\u2019s al nucli, on els gens es poden activar per tenir funcions reproductives, per respondre a l\u2019estr\u00e8s o per crear m\u00fasculs. Aquest tipus de senyalitzaci\u00f3 pot trigar alguns minuts, mentre que un prot\u00f3 que arriba a les c\u00e8l\u00b7lules per la retina de l\u2019ull t\u00e9 una resposta immediata.<\/p>\n<p>&nbsp;<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-5885 aligncenter\" src=\"https:\/\/ellipse.prbb.org\/wp-content\/uploads\/2012\/05\/Comunicaci\u00f3Celular_cat.png\" alt=\"\" width=\"658\" height=\"941\" srcset=\"https:\/\/ellipse.prbb.org\/wp-content\/uploads\/2012\/05\/Comunicaci\u00f3Celular_cat.png 1499w, https:\/\/ellipse.prbb.org\/wp-content\/uploads\/2012\/05\/Comunicaci\u00f3Celular_cat-157x224.png 157w, https:\/\/ellipse.prbb.org\/wp-content\/uploads\/2012\/05\/Comunicaci\u00f3Celular_cat-768x1098.png 768w, https:\/\/ellipse.prbb.org\/wp-content\/uploads\/2012\/05\/Comunicaci\u00f3Celular_cat-419x600.png 419w\" sizes=\"auto, (max-width: 658px) 100vw, 658px\" \/><\/p>\n<p>&nbsp;<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Per produir una resposta cel\u00b7lular adequada, les c\u00e8l\u00b7lules han desenvolupat una \u00e0mplia varietat de processos per transmetre senyals des de l\u2019exterior fins al seu interior.<\/p>\n","protected":false},"author":9,"featured_media":5867,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[30],"tags":[269,297,312,513],"new-type":[35],"class_list":["post-5723","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-ciencia-i-societat","tag-biologia-cellular","tag-biologia-molecular","tag-cancer-ca","tag-ciencia-al-descobert","new-type-noticies"],"acf":[],"_links":{"self":[{"href":"https:\/\/ellipse.prbb.org\/ca\/wp-json\/wp\/v2\/posts\/5723","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/ellipse.prbb.org\/ca\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/ellipse.prbb.org\/ca\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/ellipse.prbb.org\/ca\/wp-json\/wp\/v2\/users\/9"}],"replies":[{"embeddable":true,"href":"https:\/\/ellipse.prbb.org\/ca\/wp-json\/wp\/v2\/comments?post=5723"}],"version-history":[{"count":5,"href":"https:\/\/ellipse.prbb.org\/ca\/wp-json\/wp\/v2\/posts\/5723\/revisions"}],"predecessor-version":[{"id":40203,"href":"https:\/\/ellipse.prbb.org\/ca\/wp-json\/wp\/v2\/posts\/5723\/revisions\/40203"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/ellipse.prbb.org\/ca\/wp-json\/wp\/v2\/media\/5867"}],"wp:attachment":[{"href":"https:\/\/ellipse.prbb.org\/ca\/wp-json\/wp\/v2\/media?parent=5723"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/ellipse.prbb.org\/ca\/wp-json\/wp\/v2\/categories?post=5723"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/ellipse.prbb.org\/ca\/wp-json\/wp\/v2\/tags?post=5723"},{"taxonomy":"new-type","embeddable":true,"href":"https:\/\/ellipse.prbb.org\/ca\/wp-json\/wp\/v2\/new-type?post=5723"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}