{"id":61347,"date":"2025-08-30T14:04:26","date_gmt":"2025-08-30T08:34:26","guid":{"rendered":"https:\/\/vajiramandravi.com\/current-affairs\/?p=61347"},"modified":"2025-08-30T14:16:10","modified_gmt":"2025-08-30T08:46:10","slug":"mitochondrial-protein-import","status":"publish","type":"post","link":"https:\/\/vajiramandravi.com\/current-affairs\/mitochondrial-protein-import\/","title":{"rendered":"Mitochondrial Protein Import"},"content":{"rendered":"<h2><strong>Mitochondrial Protein Import Latest News<\/strong><\/h2>\n<p><span style=\"font-weight: 400;\">Recently, researchers at Caltech University have uncovered new rules governing mitochondrial protein import, revising the long-standing understanding of how proteins are transported into mitochondria.<\/span><\/p>\n<h2><strong>About Mitochondria<\/strong><\/h2>\n<ul>\n<li style=\"font-weight: 400;\" aria-level=\"1\"><b>Mitochondria<\/b><span style=\"font-weight: 400;\"> are double-membraned organelles that generate <\/span><b>ATP (adenosine triphosphate)<\/b><span style=\"font-weight: 400;\">, the universal cellular energy currency.<\/span><\/li>\n<li style=\"font-weight: 400;\" aria-level=\"1\"><span style=\"font-weight: 400;\">They originated over <\/span><b>a billion years ago<\/b><span style=\"font-weight: 400;\"> through <\/span><b>endosymbiosis<\/b><span style=\"font-weight: 400;\"> between a primitive archaeal cell and a bacterium.<\/span><\/li>\n<li style=\"font-weight: 400;\" aria-level=\"1\"><span style=\"font-weight: 400;\">Over time, mitochondria transferred most of their <\/span><b>genes to the host nucleus<\/b><span style=\"font-weight: 400;\">, making them dependent on the host cell for protein supply.<\/span><\/li>\n<\/ul>\n<h3><strong>Traditional Model of Protein Import<\/strong><\/h3>\n<ul>\n<li style=\"font-weight: 400;\" aria-level=\"1\"><span style=\"font-weight: 400;\">Earlier, it was believed that <\/span><b>mitochondrial proteins are imported only after translation<\/b><span style=\"font-weight: 400;\"> is completed in the cytosol.<\/span><\/li>\n<li style=\"font-weight: 400;\" aria-level=\"1\"><span style=\"font-weight: 400;\">Proteins were thought to fully synthesize on ribosomes before passing through mitochondrial membrane channels.<\/span><\/li>\n<\/ul>\n<h2><strong>New Findings by Caltech Scientists<\/strong><\/h2>\n<ul>\n<li style=\"font-weight: 400;\" aria-level=\"1\"><span style=\"font-weight: 400;\">Around <\/span><b>20% of mitochondrial proteins are cotranslationally imported<\/b><span style=\"font-weight: 400;\">, i.e., they are imported <\/span><b>while still being synthesized<\/b><span style=\"font-weight: 400;\"> by ribosomes.<\/span><\/li>\n<li style=\"font-weight: 400;\" aria-level=\"1\"><span style=\"font-weight: 400;\">This mechanism mainly applies to <\/span><b>large and structurally complex proteins<\/b><span style=\"font-weight: 400;\"> that require assistance during folding.<\/span><\/li>\n<li style=\"font-weight: 400;\" aria-level=\"1\"><span style=\"font-weight: 400;\">If these proteins fully fold in the cytosol, they risk forming <\/span><b>irreversible structures<\/b><span style=\"font-weight: 400;\"> that block import channels.<\/span><\/li>\n<\/ul>\n<h2><strong>Mechanism of Cotranslational Import<\/strong><\/h2>\n<ul>\n<li style=\"font-weight: 400;\" aria-level=\"1\"><span style=\"font-weight: 400;\">Such proteins contain a <\/span><b>mitochondrial targeting sequence<\/b><span style=\"font-weight: 400;\">, but this alone is insufficient for cotranslational delivery.<\/span><\/li>\n<li style=\"font-weight: 400;\" aria-level=\"1\"><span style=\"font-weight: 400;\">A <\/span><b>second signal<\/b><span style=\"font-weight: 400;\"> is required \u2013 the <\/span><b>first large protein domain<\/b><span style=\"font-weight: 400;\"> that emerges during translation.<\/span><\/li>\n<li style=\"font-weight: 400;\" aria-level=\"1\"><span style=\"font-weight: 400;\">This domain acts like a <\/span><b>\u201ccode to unlock the boarding pass\u201d<\/b><span style=\"font-weight: 400;\">, ensuring the protein is guided into mitochondria early.<\/span><\/li>\n<li style=\"font-weight: 400;\" aria-level=\"1\"><span style=\"font-weight: 400;\">Experiments confirmed that <\/span><b>transplanting these domains<\/b><span style=\"font-weight: 400;\"> onto other proteins rerouted them for cotranslational import.<\/span><\/li>\n<\/ul>\n<p><b>Source: <\/b><a href=\"https:\/\/phys.org\/news\/2025-08-biochemists-uncover-mitochondrial-protein-import.html\" target=\"_blank\" rel=\"nofollow noopener\"><b>PHY<\/b><\/a><\/p>\n","protected":false},"excerpt":{"rendered":"<p>Mitochondria are double-membraned organelles that generate ATP (adenosine triphosphate), the universal cellular energy currency. Read more about Mitochondrial Protein Import, Traditional Model, New Findings, News<\/p>\n","protected":false},"author":8,"featured_media":61328,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[1],"tags":[2412,21,22,23],"class_list":{"0":"post-61347","1":"post","2":"type-post","3":"status-publish","4":"format-standard","5":"has-post-thumbnail","7":"category-upsc-prelims-current-affairs","8":"tag-mitochondrial-protein-import","9":"tag-prelims-pointers","10":"tag-upsc-current-affairs","11":"tag-upsc-prelims-current-affairs","12":"no-featured-image-padding"},"acf":[],"_links":{"self":[{"href":"https:\/\/vajiramandravi.com\/current-affairs\/wp-json\/wp\/v2\/posts\/61347","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/vajiramandravi.com\/current-affairs\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/vajiramandravi.com\/current-affairs\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/vajiramandravi.com\/current-affairs\/wp-json\/wp\/v2\/users\/8"}],"replies":[{"embeddable":true,"href":"https:\/\/vajiramandravi.com\/current-affairs\/wp-json\/wp\/v2\/comments?post=61347"}],"version-history":[{"count":0,"href":"https:\/\/vajiramandravi.com\/current-affairs\/wp-json\/wp\/v2\/posts\/61347\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/vajiramandravi.com\/current-affairs\/wp-json\/wp\/v2\/media\/61328"}],"wp:attachment":[{"href":"https:\/\/vajiramandravi.com\/current-affairs\/wp-json\/wp\/v2\/media?parent=61347"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/vajiramandravi.com\/current-affairs\/wp-json\/wp\/v2\/categories?post=61347"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/vajiramandravi.com\/current-affairs\/wp-json\/wp\/v2\/tags?post=61347"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}