Fig. 1

p30 in viral replication. The p30 protein mainly localizes into the nucleolus and represses viral replication by targeting the Tax/Rex mRNA. Absent Rex in the early stages of infection, the HTLV-1 viral transcripts are fully spliced, and Tax and Rex are translated. The oncoprotein Tax transactivates the long terminal repeat promoter, amplifying viral expression. Rex exports the unspliced and singly spliced viral mRNA from the nucleus to cytoplasm, leading to the expression of structural proteins and the production of viral particles. In the late stages of infection, p30 directly interacts with Rex, binds the doubly spliced Tax/Rex mRNA and decreases both Tax and Rex protein levels, leading to viral latency