RNA editing

Marić, Tihana (2015) RNA editing. Bachelor's thesis, Faculty of Science > Department of Biology.

Language: Croatian

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RNA editing describes molecular processes that include posttranscriptional changes in RNA nucleotide sequence compared to coding DNA sequence and may be necessary for their biological function. It is spread in eukaryotes, and it also occurs in some RNA viruses. Nucleus, mitochondria and plastids are cellular compartments in which RNA editing occurs. Also transcripts to be edited are not necessarily protein coding. There are two main groups of RNA editing – editing by substitution of nucleotides and insertions or deletions in which number of nucleotides in RNA transcripts is changed. For substitution editing, there are two main protein systems in mammals – APOBEC and ADAR. APOBEC has cytidine deaminase activity and conducts C to U deamination whereas ADARs are adenosine deaminases and they change A→I. Protozan RNA editing includes editing of mitochondrial RNA transcripts. Typical editing for trypanosomatid protozoans involves insertion as well as deletion of U in protein coding RNA transcripts. RNA editing in protoza Acanthoamoebe castelanii includes editing of 5’-end of tRNA acceptor stem. In plants C to U editing is the most common type of modification. Mitochondrial and plastids RNAs are targeted for editing in this case. RNA of viruses, like Ebolavirus and hepatitis delta virus, can also undergo editing using its own or host protein complexes. It can largely affect their virulence. RNA editing is complex and energetically expensive process so there is open question why did it even arose. Constructive neutral evolution model tries to give satisfying answer. It proposes that RNA editing system emerged after allowing mutations to happen. RNA editing allows corrections of DNA mutations on RNA level and therefore it permits DNA-encoded information to degenerate progressively.

Item Type: Thesis (Bachelor's thesis)
Supervisor: Rokov Plavec, Jasmina
Date: 2015
Number of Pages: 23
Subjects: NATURAL SCIENCES > Biology
Divisions: Faculty of Science > Department of Biology
Depositing User: Silvana Šehić
Date Deposited: 14 Apr 2016 10:11
Last Modified: 14 Apr 2016 10:11
URI: http://digre.pmf.unizg.hr/id/eprint/4716

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