{"id":48107,"date":"2025-05-19T15:47:17","date_gmt":"2025-05-19T10:17:17","guid":{"rendered":"https:\/\/vajiramandravi.com\/current-affairs\/?p=48107"},"modified":"2025-05-27T16:16:54","modified_gmt":"2025-05-27T10:46:54","slug":"a-to-i-mrna-editing-in-animals","status":"publish","type":"post","link":"https:\/\/vajiramandravi.com\/current-affairs\/a-to-i-mrna-editing-in-animals\/","title":{"rendered":"A-to-I mRNA Editing in Animals"},"content":{"rendered":"<h2>A-to-I mRNA Editing in Animals Latest News<\/h2>\n<p>Researchers from China recently reported that it\u2019s hard to make sense of the widespread persistence of A-to-I mRNA editing in animals.<\/p>\n<h2>Concept and Mechanism<\/h2>\n<ul>\n<li><strong>DNA acts like a recipe book<\/strong>\u00a0for building proteins using\u00a0<strong>20 amino acids<\/strong>. Each recipe (i.e., gene) is transcribed into\u00a0<strong>messenger RNA (mRNA)<\/strong>.<\/li>\n<li>The\u00a0<strong>mRNA<\/strong>\u00a0is then read by\u00a0<strong>ribosomes<\/strong>\u00a0to assemble proteins. The mRNA is composed of\u00a0<strong>four nucleotide bases<\/strong>: A (adenosine), U, G, and C.<\/li>\n<li>In\u00a0<strong>A-to-I mRNA editing<\/strong>, the\u00a0<strong>adenosine (A)<\/strong>\u00a0in mRNA is\u00a0<strong>enzymatically converted<\/strong>\u00a0into\u00a0<strong>inosine (I)<\/strong>\u00a0by proteins called\u00a0<strong>ADARs (Adenosine Deaminase Acting on RNA)<\/strong>.<\/li>\n<li>The ribosome reads\u00a0<strong>inosine as guanine (G)<\/strong>, altering the protein\u2019s amino acid sequence\u00a0<strong>post-transcriptionally<\/strong>, without any change in the DNA.<\/li>\n<li><strong>Functional Impact:\u00a0<\/strong>A-to-I editing can change the\u00a0<strong>codon identity<\/strong>, thereby producing\u00a0<strong>a different amino acid<\/strong>\u00a0in the resulting protein.\n<ul>\n<li>This may lead to\u00a0<strong>functional protein diversification and\u00a0<\/strong>alteration in\u00a0<strong>protein stability or activity<\/strong>.<\/li>\n<\/ul>\n<\/li>\n<li>A major risk is\u00a0<strong>misreading stop codons<\/strong>:\n<ul>\n<li>A stop codon like\u00a0<strong>UAG or UGA<\/strong>\u00a0may be edited to\u00a0<strong>UGG<\/strong>, coding for\u00a0<strong>tryptophan<\/strong>.<\/li>\n<li>This allows the ribosome to\u00a0<strong>continue protein synthesis<\/strong>, potentially creating\u00a0<strong>abnormally long or malfunctioning proteins<\/strong>.<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<h2>Discovery of PSC Genes<\/h2>\n<ul>\n<li>Researchers identified\u00a0<strong>71 genes<\/strong>\u00a0in\u00a0<i>F. graminearum<\/i>\u00a0that contain\u00a0<strong>premature stop codons<\/strong>\u00a0(UAG) in their unedited mRNA.<\/li>\n<li>These were termed\u00a0<strong>PSC (premature stop codon-containing) genes<\/strong>.<\/li>\n<li>Deleting these genes had:\n<ul>\n<li><strong>No impact during asexual growth<\/strong>.<\/li>\n<li>But significant\u00a0<strong>disruption during sexual development<\/strong>, proving the\u00a0<strong>essentiality of A-to-I editing<\/strong>\u00a0in these stages.<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<h2>A-to-I mRNA Editing in Animals FAQs<\/h2>\n<p><strong>Q1:\u00a0<\/strong>What is A-to-I mRNA editing?<br \/>\n<strong>Ans:<\/strong>\u00a0A-to-I mRNA editing is a post-transcriptional RNA modification where adenosine (A) is converted to inosine (I) by the ADAR (Adenosine Deaminase Acting on RNA) enzyme.<\/p>\n<p><strong>Q2:\u00a0<\/strong>What is the significance of inosine in mRNA?<br \/>\n<strong>Ans:<\/strong>\u00a0Inosine is read as guanosine (G) by the cellular machinery, which can alter the resulting protein sequence, potentially affecting its function.<\/p>\n<p><strong>Source:\u00a0<\/strong><a href=\"https:\/\/www.thehindu.com\/sci-tech\/science\/our-bodies-perform-a-kind-of-mrna-editing-and-we-dont-know-why\/article69423396.ece\" target=\"_blank\" rel=\"nofollow noopener\">TH<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"<p>A-to-I mRNA editing is a post-transcriptional RNA modification where adenosine (A) is converted to inosine (I) by the ADAR (Adenosine Deaminase Acting on RNA) enzyme.<\/p>\n","protected":false},"author":8,"featured_media":48013,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[1],"tags":[549,21,22,23],"class_list":{"0":"post-48107","1":"post","2":"type-post","3":"status-publish","4":"format-standard","5":"has-post-thumbnail","7":"category-upsc-prelims-current-affairs","8":"tag-a-to-i-mrna-editing-in-animals","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\/48107","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=48107"}],"version-history":[{"count":0,"href":"https:\/\/vajiramandravi.com\/current-affairs\/wp-json\/wp\/v2\/posts\/48107\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/vajiramandravi.com\/current-affairs\/wp-json\/wp\/v2\/media\/48013"}],"wp:attachment":[{"href":"https:\/\/vajiramandravi.com\/current-affairs\/wp-json\/wp\/v2\/media?parent=48107"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/vajiramandravi.com\/current-affairs\/wp-json\/wp\/v2\/categories?post=48107"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/vajiramandravi.com\/current-affairs\/wp-json\/wp\/v2\/tags?post=48107"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}