G‐quadruplexes in RNA biology

G‐quadruplexes are noncanonical structures formed by G‐rich DNA and RNA sequences that fold into a four‐stranded conformation. Experimental studies and computational predictions show that RNA G‐quadruplexes are present in transcripts associated with telomeres, in noncoding sequences of primary transcripts and within mature transcripts. RNA G‐quadruplexes at these specific locations play important roles in key cellular functions, including telomere homeostasis and gene expression. Indeed, RNA G‐quadruplexes appear as important regulators of pre‐mRNA processing (splicing and polyadenylation), RNA turnover, mRNA targeting and translation. The regulatory mechanisms controlled by RNA G‐quadruplexes involve the binding of protein factors that modulate G‐quadruplex conformation and/or serve as a bridge to recruit additional protein regulators. In this review, we summarize the current knowledge on the role of G‐quadruplexes in RNA biology with particular emphasis on the molecular mechanisms underlying their specific function in RNA metabolism occurring in physiological or pathological conditions. WIREs RNA 2012, 3:495–507. doi: 10.1002/wrna.1113 This article is categorized under: RNA Structure and Dynamics > Influence of RNA Structure in Biological Systems RNA Interactions with Proteins and Other Molecules > Protein–RNA Interactions: Functional Implications