Chapter 22 m RNA Stability and Localization. 22.1 Introduction. 3′ untranslated region (UTR) – The untranslated sequence downstream from the coding region of an mRNA. 5′ untranslated region (UTR) – The untranslated sequence upstream from the coding region of an mRNA. 22.1 Introduction.
Figure 22.01: Features of prokaryotic and eukaryotic mRNAs. (a) A typical bacterial mRNA.
Figure 22.02: Types of ribonucleases. Exonucleases are unidirectional.
Figure 22.03: Method for determining mRNA half-lives.
mRNA associates with a changing population of proteins during its nuclear maturation and cytoplasmic life.
Some nuclear-acquired mRNP proteins have roles in the cytoplasm.
A very large number of RNA-binding proteins (RBPs) exist, most of which remain uncharacterized.
Different mRNAs are associated with distinct, but overlapping, sets of regulatory proteins, creating RNA regulons.22.3 Eukaryotic mRNAs Exist in the Form of mRNPs from Their Birth to Their Death
Figure 22.04: The concept of an RNA regulon.
Figure 22.05: Degradation of bacterial mRNAs.
Figure 22.06: The major deadenylation-dependent decay pathways in eukaryotes.
Figure 22.08: Other decay pathways in eukaryotic cells. The initiating event for each pathway is illustrated.
Figure 22.09: Table summarizing key elements of mRNA decay pathways in eukaryotic cells.
Figure 22.10: Mechanisms by which destabilizing elements (DEs) and stabilizing elements (SEs) function.
Figure 22.11: Regulation of transferring mRNA stability by iron levels.
Figure 22.12: The role of TRAMP and the exosome in degrading aberrant nuclear RNAs.
Figure 22.14: Two mechanisms by which a termination codon is recognized as premature.
Figure 22.13: Substrates for cytoplasmic surveillance systems.
Figure 22.16: Three main functions of mRNA localization.
Figure 22.17: Localization of Ash1 mRNA.