RNA editing mechanisms

Blanc, V. Davidson, N.O. (2003) C-to-U RNA editing mechanisms leading to genetic diversity J. Biol. Chem. 278, 1395-1398. 

FIGURE 1.17 A RNA editing mechanism involving transesterification reactions under the direction of a guide RNA. 

Seeburg PH, Higuchi M, Sprengel R (1998) RNA editing of glutamate receptor channels mechanism and physiology. Brain Res Brain Res Rev 26 217-219... 

RNA-editing is a posttranscriptional mechanism mediated by RNA editases, which results in a site-selective deamination of adenosine to inosine. This alters codons and splicing in nuclear transcripts and thereby alters the structure and function of proteins. 

The suppressor tRNA developed by the Chamberlin lab for use in a rabbit reticulocyte lysate is based on an E. coli glycyl tRNA, which was initially chosen because glycyl-tRNA synthetases do not rely on a double-sieve editing mechanism for enzymatic hydrolysis of misacylated tRNAs [26]. Two base pair changes were made to the acceptor stem to allow incorporation of the optimal T7 RNA polymerase promoter into the DNA template for tRNA y-Con [27,28],... 

MICROTUBULE ASSEMBLY KINETICS RITCHIE EQUATION RNA, exonucleolytic cleavage, PHOSPHODIESTERASES RNA LIGASE RNA POLYMERASES EDITING MECHANISMS REPLICASE RNA stability,... 

These processes are summarized in Figure 28-1. We have examined several of these mechanisms in previous chapters. Posttranscriptional modification of mRNA, by processes such as alternative splicing patterns (see Fig. 26-19b) or RNA editing (see Box 27-1), can affect which proteins are produced from an mRNA transcript and in what amounts. A variety of nucleotide sequences in an mRNA can affect the rate of its degradation (p. 1020). Many factors affect the rate at which an mRNA is translated into a protein, as well as the posttranslational modification, targeting, and eventual degradation of that protein (Chapter 27). 

RNA editing. A shortened version (apo B-48) of apolipoprotein B is formed by the intestine, whereas the full-length protein (apo B-lOO) is synthesized by the liver. A glutamine codon (CAA) is changed into a stop codon. Propose a simple mechanism for this change. 

RNA editing. Many uridine molecules are inserted into some mitochondrial mRNAs in trypanosomes. The uridine residues come from the poly(U) tail of a donor strand. Nucleoside triphosphates do not participate in this reaction. Propose a reaction mechanism that accounts for these findings. (Hint Relate RNA editing to RNA splicing.)... 

RNA editing the alteration of the base sequence in a newly synthesized mRNA molecule bases may be chemically modified, deleted, or added RNA transposon a transposition mechanism that involves an RNA transcript also referred to as a retrotransposon rough ER a type of endoplasmic reticulum involved in protein synthesis... 

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