{"id":15657,"date":"2020-06-04T15:08:58","date_gmt":"2020-06-04T13:08:58","guid":{"rendered":"https:\/\/ellipse.prbb.org\/?p=15657"},"modified":"2020-06-04T15:08:14","modified_gmt":"2020-06-04T13:08:14","slug":"entenent-la-formacio-i-creixement-dels-microtubuls","status":"publish","type":"post","link":"https:\/\/ellipse.prbb.org\/ca\/entenent-la-formacio-i-creixement-dels-microtubuls\/","title":{"rendered":"Entenent la formaci\u00f3 i creixement dels microt\u00fabuls"},"content":{"rendered":"\n<p class=\"wp-block-paragraph\">Els <a rel=\"noreferrer noopener\" href=\"https:\/\/ellipse.prbb.org\/ca\/rin4%e2%80%b2-mes-que-un-concurs-de-divulgacio-cientifica\/\" target=\"_blank\">microt\u00fabuls<\/a> formen tant l&#8217;esquelet com les \u00abautopistes\u00bb de les nostres c\u00e8l\u00b7lules. No obstant, encara es desconeixen els detalls sobre com es creen aquestes estructures tan essencials. Un nou projecte de recerca liderat pel <a rel=\"noreferrer noopener\" href=\"https:\/\/www.crg.eu\/en\/programmes-groups\/surrey-lab\" target=\"_blank\">laboratori dirigit per Thomas Surrey<\/a> \u2014 qui recentment ha arribat al <a rel=\"noreferrer noopener\" href=\"http:\/\/www.crg.eu\/\" target=\"_blank\">Centre de Regulaci\u00f3 Gen\u00f2mica (CRG)<\/a> des de l&#8217;<a rel=\"noreferrer noopener\" href=\"https:\/\/www.crick.ac.uk\/\" target=\"_blank\">Institut Crick<\/a> \u2014 llan\u00e7a una mica de llum sobre com s&#8217;inicia tot aquest proc\u00e9s.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Els microt\u00fabuls consisteixen en tubs llargs fets d&#8217;unitats de tubulina (a i b) organitzades de manera circular, seguint un patr\u00f3 en forma d&#8217;h\u00e8lix<\/strong>. La formaci\u00f3 dels microt\u00fabuls consisteix en dues fases:<\/p>\n\n\n\n<ul class=\"wp-block-list\"><li><strong>Nucleaci\u00f3<\/strong>: les primeres unitats d&#8217;a\/b-tubulina s\u00f3n col\u00b7locades a la part superior d&#8217;un complex en forma d&#8217;anell format per unitats de \u03b3-tubulina, anomenat \u03b3TuRC.<\/li><li><strong>Elongaci\u00f3<\/strong>:  m\u00e9s unitats d&#8217;a\/b-tubulina s\u00f3n afegides per allargar els microt\u00fabuls.<\/li><\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">Per poder entendre com es regulen aquests processos, l&#8217;equip de cient\u00edfics i cient\u00edfiques dirigit per Thomas Surrey <strong>va purificar complexos \u03b3TuRC<\/strong> <strong>humans<\/strong> i van observar la cin\u00e8tica de la <a rel=\"noreferrer noopener\" href=\"https:\/\/ellipse.prbb.org\/ca\/estudiant-la-divisio-cel%c2%b7lular-en-granotes\/\" target=\"_blank\">formaci\u00f3 <em>in vitro<\/em> dels microt\u00fabuls<\/a>.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">El que van trobar \u00e9s que el complex \u03b3TuRC \u00e9s en realitat molt ineficient respecte al primer pas. No obstant, un cop les primeres unitats ja s&#8217;han col\u00b7locat, el proc\u00e9s d&#8217;elongaci\u00f3 \u00e9s molt m\u00e9s r\u00e0pid.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\"><\/h2>\n\n\n\n<blockquote class=\"wp-block-quote is-layout-flow wp-block-quote-is-layout-flow\"><p>\u03b3TuRC \u00e9s molt ineficient respecte al primer pas per\u00f2, un cop les primeres unitats ja s&#8217;han col\u00b7locat, el proc\u00e9s d&#8217;elongaci\u00f3 \u00e9s molt m\u00e9s r\u00e0pid.<\/p><\/blockquote>\n\n\n\n<h2 class=\"wp-block-heading\"><\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Per descobrir per qu\u00e8 \u03b3TuRC \u00e9s tan ineficient al principi, el personal investigador va comen\u00e7ar a treballar amb <a rel=\"noreferrer noopener\" href=\"https:\/\/www.crick.ac.uk\/research\/labs\/alessandro-costa\" target=\"_blank\">el laboratori d&#8217;Alessandro Costa<\/a> al Crick, qui es va encarregar d&#8217;<strong>analitzar l&#8217;estructura d&#8217;aquest complex a trav\u00e9s de criomicrosc\u00f2pia electr\u00f2nica<\/strong> \u2014 una t\u00e8cnica que permet observar estructures incre\u00efblement petites (en aquest cas fins a 4A, o 4 bilion\u00e8simes parts d&#8217;un cm).<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Van veure que, del total de les 14 subunitats de \u03b3-tubulina que formen el cercle de \u03b3TuRC, la meitat es trobaven molt juntes, en una configuraci\u00f3 compacta (tancada), mentre que l&#8217;altre meitat disposava d&#8217;espais entremig (oberta), convertint l&#8217;anell en <strong>asim\u00e8tric<\/strong>. Aquesta desviaci\u00f3 de la geometria dels microt\u00fabuls faria m\u00e9s dif\u00edcil que la tubulina a\/b s&#8217;hi afegeixi i comenci a formar els microt\u00fabuls.<\/p>\n\n\n\n<div class=\"wp-block-image\"><figure class=\"aligncenter size-large is-resized\"><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/ellipse.prbb.org\/wp-content\/uploads\/2020\/06\/Figure_5_Consolati_text-896x600.jpg\" alt=\"\" class=\"wp-image-15640\" width=\"480\" height=\"321\" srcset=\"https:\/\/ellipse.prbb.org\/wp-content\/uploads\/2020\/06\/Figure_5_Consolati_text-896x600.jpg 896w, https:\/\/ellipse.prbb.org\/wp-content\/uploads\/2020\/06\/Figure_5_Consolati_text-334x224.jpg 334w, https:\/\/ellipse.prbb.org\/wp-content\/uploads\/2020\/06\/Figure_5_Consolati_text-768x514.jpg 768w, https:\/\/ellipse.prbb.org\/wp-content\/uploads\/2020\/06\/Figure_5_Consolati_text.jpg 1181w\" sizes=\"auto, (max-width: 480px) 100vw, 480px\" \/><figcaption>L&#8217;equip investigador va trobar que la meitat de l&#8217;estructura de l&#8217;\u03b3TuRC \u00e9s compacta\/tancada, mentre que l&#8217;altra meitat est\u00e0 m\u00e9s oberta, amb espais entre les unitats de \u03b3-tubulina.<\/figcaption><\/figure><\/div>\n\n\n\n<p class=\"wp-block-paragraph\">El personal cient\u00edfic creu que la manera en la que \u03b3TuRC s&#8217;activa \u2014 i la formaci\u00f3 de microt\u00fabuls s&#8217;accelera \u2014 \u00e9s per un canvi en la conformaci\u00f3 de l&#8217;anell, passant d&#8217;una forma oberta asim\u00e8trica a una m\u00e9s compacta, m\u00e9s similar al patr\u00f3 com\u00fa de microt\u00fabuls. El repte ara est\u00e0 en descobrir quins factors estan involucrats en aquest canvi.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>El personal cient\u00edfic del laboratori de Thomas Surrey, recentment traslladat al CRG des de l&#8217;Institut Crick, llancen una mica de llum sobre com es creen els microt\u00fabuls.<\/p>\n","protected":false},"author":9,"featured_media":15636,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[26],"tags":[265,219],"new-type":[35],"class_list":["post-15657","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-recerca","tag-crg-ca","tag-microtubuls","new-type-noticies"],"acf":[],"_links":{"self":[{"href":"https:\/\/ellipse.prbb.org\/ca\/wp-json\/wp\/v2\/posts\/15657","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=15657"}],"version-history":[{"count":12,"href":"https:\/\/ellipse.prbb.org\/ca\/wp-json\/wp\/v2\/posts\/15657\/revisions"}],"predecessor-version":[{"id":15673,"href":"https:\/\/ellipse.prbb.org\/ca\/wp-json\/wp\/v2\/posts\/15657\/revisions\/15673"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/ellipse.prbb.org\/ca\/wp-json\/wp\/v2\/media\/15636"}],"wp:attachment":[{"href":"https:\/\/ellipse.prbb.org\/ca\/wp-json\/wp\/v2\/media?parent=15657"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/ellipse.prbb.org\/ca\/wp-json\/wp\/v2\/categories?post=15657"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/ellipse.prbb.org\/ca\/wp-json\/wp\/v2\/tags?post=15657"},{"taxonomy":"new-type","embeddable":true,"href":"https:\/\/ellipse.prbb.org\/ca\/wp-json\/wp\/v2\/new-type?post=15657"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}