Ribosome Shunting

Ribosome shunting is a mechanism of translation initiation in which ribosomes physically bypass, or shunt over, parts of the 5' untranslated region to reach the initiation codon. This enables viruses to have more information than usual in an mRNA molecule. Some viral RNAs have been shown to use Ribosome shunting as a more efficient form of translation during certain stages of viral life cycle or when translation initiation factors are scarce (e.g cleavage by viral proteases). Some viruses known to use this mechanism include adenovirus, Sendai virus, human papillomavirus, duck hepatitis B pararetrovirus, Rice tungro bacilliform viruses, and cauliflower mosaic virus. In these viruses the ribosome is directly translocated from the upstream initiation complex to the start codon (AUG) without the need for eIF4A helices activity to unwind RNA secondary structures.

Read more about Ribosome Shunting:  Ribosome Shunting in Cauliflower Mosaic Virus, Ribosome Shunting in Rice Tungro Bacilliform Pararetrovirus, Ribosome Shunting in Sendai Virus, Ribosome Shunt in Adenovirus