Figure 7.

Model showing the ubiquitination of HIV-1 Tat by CHIP. The multiply-spliced HIV-1 mRNA is translated resulting in expression of Tat leading to transcriptional activation of HIV-1 genome. Tat protein is degraded through the lysosomal and 20S proteasomal pathway. Tat is also ubiquitinated by host cell E3 ligase CHIP leading to its Lys-48–linked ubiquitination. Ubiquitinated Tat is recognized by 26S proteasome and degraded resulting in the inhibition of HIV-1 replication and virion production.