3′ Cap-independent translation enhancers of positive-strand RNA plant viruses

Positive-strand RNA plant viruses that are neither 5′-capped nor 3′-polyadenylated use nontraditional mechanisms to recruit ribosomes to the 5′-end of their viral genomes. One strategy employed by some of these viruses involves a type of RNA element, termed the 3′ cap-independent translation enhancer (3′CITE), located in or near the 3′-untranslated region of viral RNA genomes. 3′CITEs function to mediate efficient translation of 5′-proximally encoded viral proteins and function by recruiting either translation initiation factors or the 60S ribosomal subunit to the viral RNA. Recent mechanistic and structural studies have revealed important new insights and details of how 3′CITEs are able to facilitate viral translation and allow these viruses to compete efficiently against cellular mRNAs for the host translational machinery.

► Plant viruses utilize unique mechanisms to hijack the host translational machinery. ► 3′CITEs are a class of RNA element that performs this function in Tombusviridae. ► 3′CITEs operate by binding to translation initiation factors or ribosomal subunits. ► Major advances in the field as well as future prospects are discussed herein.