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. Author manuscript; available in PMC: 2019 Sep 18.
Published in final edited form as: Ann Integr Mol Med. 2019;1(1):1002.

Figure 5: RNA-dependent mRNA amplification can result in a 5’-truncated molecule encoding C-terminal fragment of a conventionally encoded polypeptide.

Figure 5:

Boxed line-sense strand RNA. Single line-antisense strand RNA. “AUG”-functional translation initiation codon (could be other than AUG). “TCE”- 3’-terminal complementary element; “ICE”- internal complementary element, both on the antisense RNA strand. Yellow circle – helicase/modifying activity complex. Blue lines (both single and boxed) – RNA strand modified and separated from its complement by a helicase complex. Red arrow – position of cleavage of the chimeric intermediate. Step 1: synthesis of antisense strand; step 2: strand separation; step 3: folding of antisense strand into self-priming configuration; step 4: extension of self-primed antisense RNA; step 5: strand separation; step 6: cleavage of the chimeric intermediate; stage 7: end-products of RNA amplification. Steps 3’−7’ correspond to steps 3-7. Top panel: Conventional, genome-transcribed mRNA molecule. Middle panel: projected stages of RNA-dependent mRNA amplification. “ICE” is located within a segment of antisense RNA corresponding to the 5’UTR of conventional mRNA; the chimeric RNA end product contains the entire coding content of conventional mRNA. Bottom panel: “ICE” is located within a segment of antisense RNA corresponding to the coding region of conventional mRNA. The amplified chimeric end product contains a 5’-truncated coding region of conventional mRNA. The translational outcome is decided by position of the first functional translation initiation codon; if in-frame, a CTF of conventional polypeptide is produced.