{"id":2350,"date":"2010-06-04T13:40:10","date_gmt":"2010-06-04T11:40:10","guid":{"rendered":"http:\/\/localhost\/azgad\/wordpress\/?p=2350"},"modified":"2010-06-04T13:40:29","modified_gmt":"2010-06-04T11:40:29","slug":"making-the-right-contacts-to-get-ahead","status":"publish","type":"post","link":"https:\/\/azgad.com\/?p=2350","title":{"rendered":"Making the right contacts to get ahead"},"content":{"rendered":"<p>.<br \/>\n<strong>\u05db\u05d9\u05e6\u05d3 \u05de\u05e0\u05d5\u05e2\u05d9\u05dd \u05d1\u05d9\u05d5\u05dc\u05d5\u05d2\u05d9\u05d9\u05dd \u05de\u05e6\u05dc\u05d9\u05d7\u05d9\u05dd \u05dc\u05d4\u05e1\u05d9\u05e2 \u05d7\u05d5\u05de\u05e8\u05d9\u05dd \u05d7\u05d9\u05d5\u05e0\u05d9\u05d9\u05dd \u05dc\u05d0\u05d5\u05e8\u05db\u05d5 \u05d5\u05dc\u05e8\u05d5\u05d7\u05d1\u05d5 \u05e9\u05dc \u05d4\u05ea\u05d0, <\/strong><br \/>\n.<br \/>\n<strong>A set of mutant yeast strains allows researchers to identify structural elements<br \/>\n that help motor proteins to get moving <\/strong><br \/>\n.<\/p>\n<p>.<br \/>\nCells are crisscrossed by microtubules, protein cables that provide<br \/>\n essential infrastructure and serve as \u2018highways\u2019 for moving molecular<br \/>\n cargoes. Motor proteins, such as kinesin that travels along microtubules<br \/>\n via a multi-step \u2018walking\u2019 mechanism, effectively drive this transport.<br \/>\n The broad strokes of this process are well understood generally, but<br \/>\n new work from Etsuko Muto and Seiichi Uchimura of the RIKEN Brain<br \/>\n Science Institute in Wako in collaboration with physicists at Waseda<br \/>\nUniversity, Tokyo, has revealed valuable new details about how microtubule<br \/>\n interactions facilitate kinesin movement.<br \/>\n.<br \/>\nKinesin is associated with the nucleotide molecule adenosine diphosphate<br \/>\n(ADP) when it first binds microtubules, after which it undergoes a structural<br \/>\n change that triggers release of ADP and enables interaction with adenosine<br \/>\n triphosphate (ATP). Subsequent enzymatic processing of ATP into ADP triggers<br \/>\n additional structural changes, causing kinesin to move forward along the<br \/>\nmicrotubule while also returning the protein to its initial ADP-bound state.<br \/>\n.<br \/>\nMicrotubules are composed of dimers of the protein \u03b1- and \u03b2-tubulin, but<br \/>\neukaryotic cells can have numerous different tubulin subtypes, making it<br \/>\n challenging to investigate molecular-level details of kinesin\u2013tubulin interaction.<br \/>\nTo overcome this problem, Muto and Uchimura developed yeast strains that<br \/>\n express only a single subtype each of \u03b1- and \u03b2-tubulin, thus enabling simple<br \/>\nscreening of the effects of individual tubulin mutations. In their most recent work,<br \/>\nthey have used this approach to extensively characterize points of interaction<br \/>\n between kinesin and microtubules by generating 36 yeast strains with<br \/>\nindividual mutations in either tubulin subunit.<br \/>\n.<br \/>\nTheir data suggest that \u03b1-tubulin is primarily responsible in the initial association<br \/>\n with kinesin-ADP, with \u03b2-tubulin providing important stabilizing interactions<br \/>\nfollowing the release of ADP . The researchers were particularly surprised<br \/>\nto note that mutations targeting one highly conserved glutamate (E415) in \u03b1-tubulin<br \/>\n caused a five-fold reduction in kinesin enzymatic activity, apparently by impairing<br \/>\n binding-induced release of ADP. \u201cOur results indicate that kinesin binding to residue<br \/>\n E415 in \u03b1-tubulin transmits a signal to the kinesin nucleotide pocket, triggering its<br \/>\nconformational change and leading to release of ADP,\u201d explains Muto. \u201cI did not expect<br \/>\n that residues in \u03b1-tubulin would play such an important role.\u201d<br \/>\n.<br \/>\nIn future studies, Muto and Uchimura hope to further dissect the amino acid network<br \/>\nthat communicates these structural changes across the kinesin protein. Since microtubules<br \/>\nplay a key role in diverse cellular functions beyond molecular transport, Muto believes<br \/>\n that their mutational analysis strategy should also offer a powerful tool for studying<br \/>\nprocesses ranging from the separation of chromosome pairs during cell division to<br \/>\ncilia-mediated cell propulsion.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>. \u05db\u05d9\u05e6\u05d3 \u05de\u05e0\u05d5\u05e2\u05d9\u05dd \u05d1\u05d9\u05d5\u05dc\u05d5\u05d2\u05d9\u05d9\u05dd \u05de\u05e6\u05dc\u05d9\u05d7\u05d9\u05dd \u05dc\u05d4\u05e1\u05d9\u05e2 \u05d7\u05d5\u05de\u05e8\u05d9\u05dd \u05d7\u05d9\u05d5\u05e0\u05d9\u05d9\u05dd \u05dc\u05d0\u05d5\u05e8\u05db\u05d5 \u05d5\u05dc\u05e8\u05d5\u05d7\u05d1\u05d5 \u05e9\u05dc \u05d4\u05ea\u05d0, . A set of mutant yeast strains allows researchers to identify structural elements that help motor proteins to get moving . . Cells are crisscrossed by microtubules, protein cables that provide essential infrastructure and serve as \u2018highways\u2019 for moving molecular cargoes. Motor proteins, &hellip; <\/p>\n<p><a class=\"more-link btn\" href=\"https:\/\/azgad.com\/?p=2350\">\u05d4\u05de\u05e9\u05d9\u05db\u05d5 \u05d1\u05e7\u05e8\u05d9\u05d0\u05d4<\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_monsterinsights_skip_tracking":false,"_monsterinsights_sitenote_active":false,"_monsterinsights_sitenote_note":"","_monsterinsights_sitenote_category":0,"footnotes":""},"categories":[10],"tags":[513,186],"class_list":["post-2350","post","type-post","status-publish","format-standard","hentry","category-10","tag-513","tag-186","nodate","item-wrap"],"_links":{"self":[{"href":"https:\/\/azgad.com\/index.php?rest_route=\/wp\/v2\/posts\/2350","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/azgad.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/azgad.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/azgad.com\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/azgad.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=2350"}],"version-history":[{"count":2,"href":"https:\/\/azgad.com\/index.php?rest_route=\/wp\/v2\/posts\/2350\/revisions"}],"predecessor-version":[{"id":2352,"href":"https:\/\/azgad.com\/index.php?rest_route=\/wp\/v2\/posts\/2350\/revisions\/2352"}],"wp:attachment":[{"href":"https:\/\/azgad.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=2350"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/azgad.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=2350"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/azgad.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=2350"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}