This chapter discusses how open reading frames (ORFs) of some RNAs can be altered after transcription by RNA editing. The chapter highlights the important role RNA editing plays in keeping selfish DNA elements in the genome in check. It also mentions the significant role RNA editing plays in enabling tRNAs to translate mRNAs efficiently, which is a process that is conserved between bacteria and eukaryotes. The chapter explains how RNA editing changes the sequence of RNAs once they have already been transcribed. It analyses RNA editing through base modification that changes the chemical identity of nucleotides already present within the transcript.
Chapter
RNA editing
Chapter
RNA Synthesis and Processing
This chapter discusses the initial level at which gene expression is regulated in both
prokaryotic and eukaryotic cells, which is the first step in expression of a gene and
transcription of DNA into RNA. It highlights different types of RNA that play distinct roles
in cells, such as messenger RNAs (mRNAs) that serve as templates for protein synthesis. It
also considers other noncoding RNAs function in gene regulation, mRNA splicing, rRNA
processing, and protein sorting in eukaryotes. The chapter examines the roles of noncoding
RNAs as regulators of gene expression in eukaryotic cells. It describes mRNA processing and
the roles of snRNAs and patterns of alternative splicing, including RNA editing.
Book
David Elliott and Michael Ladomery
Molecular Biology of RNA provides an overview of a cutting-edge field of biology. It starts with an introduction to the subject. It looks at how RNA can form versatile structures. It moves on to consider catalytic RNAs. Other topics covered include pre-mRNA splicing by the spliceosome, the RNA-binding proteins, pre-mRNA splicing defects found in development and disease, and co-transcriptional pre-mRNA processing. The text also looks at nucleocytoplasmic traffic of messenger RNA, messenger RNA localization, and translation of messenger RNA. It also examines stability and degradation of mRNA and RNA editing. Finally, the text provides an analysis on biogenesis and nucleocytoplasmic traffic of non-coding RNAs; the 'macro' RNAs, which include long non-coding RNAs and epigenetics; and the short non-coding RNAs and gene silencing. The text ends with a quick look at future perspectives.
Chapter
RNA processing
This chapter explores RNA processing events, which are points for regulation and quality control, and are sources of diversity. Many RNA processing reactions are directed by RNA components. Transfer RNAs (tRNAs) and ribosomal RNAs (rRNAs) are processed out of longer precursor transcripts, and the nucleotides are post-transcriptionally modified. Meanwhile, the maturation of eukaryotic messenger RNAs (mRNAs) requires the addition of a 5' cap and a poly(A) tail—processes that are closely tied to transcription, splicing, transport out of the nucleus, and ultimately translation. The chapter then explains RNA splicing, RNA editing, and RNA degradation. RNA splicing allows the generation of great diversity in RNA products and can be catalysed by the RNA itself (self-splicing) or by a large protein and RNA-containing complex called the spliceosome. The chapter also looks at RNA-binding domains in proteins.
