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.
Chapter 22mRNA Stability and Localization
Figure 22.01: Features of prokaryotic and eukaryotic mRNAs. (a) A typical bacterial mRNA.
Figure 22.02: Types of ribonucleases. Exonucleases are unidirectional.
22.2 Messenger RNAs Are Unstable Molecules
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.
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.