{"id":254221,"date":"2025-07-12T11:57:14","date_gmt":"2025-07-12T11:57:14","guid":{"rendered":"https:\/\/learnexams.com\/blog\/?p=254221"},"modified":"2025-07-12T11:57:16","modified_gmt":"2025-07-12T11:57:16","slug":"c-to-u-editing-has-only-been-identified-in-one-protein","status":"publish","type":"post","link":"https:\/\/www.learnexams.com\/blog\/2025\/07\/12\/c-to-u-editing-has-only-been-identified-in-one-protein\/","title":{"rendered":"C-to-U editing has only been identified in one protein"},"content":{"rendered":"\n<p>C-to-U editing has only been identified in one protein. What is that protein called?<\/p>\n\n\n\n<p><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-ast-global-color-6-color\">The correct answer and explanation is:<\/mark><\/strong><\/p>\n\n\n\n<p>The protein in which C-to-U editing has been identified is <strong>apolipoprotein B (ApoB)<\/strong>. This is an important protein that plays a central role in lipid metabolism and the formation of lipoproteins, which transport cholesterol and triglycerides in the bloodstream.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Explanation:<\/h3>\n\n\n\n<p>C-to-U editing refers to a specific form of RNA editing where a cytosine (C) nucleotide is changed into a uracil (U) in the RNA sequence. This process is catalyzed by enzymes known as <strong>ADARs (adenosine deaminases acting on RNA)<\/strong>.<\/p>\n\n\n\n<p>In the case of ApoB, the C-to-U editing occurs in the <strong>mRNA transcript<\/strong> of the <strong>ApoB gene<\/strong>. The modification of a single cytosine to uracil leads to a change in the encoded protein. Specifically, this editing occurs at a particular site in the ApoB mRNA, which results in the creation of two different forms of the protein: <strong>ApoB-100<\/strong> and <strong>ApoB-48<\/strong>.<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>ApoB-100<\/strong> is a full-length protein, composed of 100% of the amino acid sequence encoded by the mRNA.<\/li>\n\n\n\n<li><strong>ApoB-48<\/strong> is a truncated version, produced because of the C-to-U editing event. The mRNA editing leads to a premature stop codon, which causes the translation machinery to halt early, producing a shorter version of the protein.<\/li>\n<\/ul>\n\n\n\n<p>This editing event is crucial for regulating the function of lipoproteins, particularly in the liver and intestines. ApoB-48, for example, is primarily found in chylomicrons in the intestines, while ApoB-100 is involved in the formation of very low-density lipoproteins (VLDL) in the liver.<\/p>\n\n\n\n<p>The discovery of C-to-U editing in ApoB highlights its importance in post-transcriptional regulation and protein diversity, showing how RNA modifications can control the function and structure of proteins without altering the DNA sequence.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>C-to-U editing has only been identified in one protein. What is that protein called? The correct answer and explanation is: The protein in which C-to-U editing has been identified is apolipoprotein B (ApoB). This is an important protein that plays a central role in lipid metabolism and the formation of lipoproteins, which transport cholesterol and [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"site-sidebar-layout":"default","site-content-layout":"","ast-site-content-layout":"default","site-content-style":"default","site-sidebar-style":"default","ast-global-header-display":"","ast-banner-title-visibility":"","ast-main-header-display":"","ast-hfb-above-header-display":"","ast-hfb-below-header-display":"","ast-hfb-mobile-header-display":"","site-post-title":"","ast-breadcrumbs-content":"","ast-featured-img":"","footer-sml-layout":"","ast-disable-related-posts":"","theme-transparent-header-meta":"","adv-header-id-meta":"","stick-header-meta":"","header-above-stick-meta":"","header-main-stick-meta":"","header-below-stick-meta":"","astra-migrate-meta-layouts":"default","ast-page-background-enabled":"default","ast-page-background-meta":{"desktop":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"ast-content-background-meta":{"desktop":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"footnotes":""},"categories":[25],"tags":[],"class_list":["post-254221","post","type-post","status-publish","format-standard","hentry","category-exams-certification"],"_links":{"self":[{"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/posts\/254221","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/comments?post=254221"}],"version-history":[{"count":0,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/posts\/254221\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/media?parent=254221"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/categories?post=254221"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/tags?post=254221"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}