KSHV vIL-6 promotes SIRT3-induced deacetylation of SERBP1 to inhibit ferroptosis and enhance cellular transformation by inducing lipoyltransferase 2 mRNA degradation.

Ferroptosis, a defensive strategy commonly employed by the host cells to restrict pathogenic infections, has been implicated in the development and therapeutic responses of various types of cancer. However, the role of ferroptosis in oncogenic Kaposi's sarcoma-associated herpesvirus (KSHV)-induced cancers remains elusive. While a growing number of non-histone proteins have been identified as acetylation targets, the functions of these modifications have yet to be revealed. Here, we show KSHV reprogramming of host acetylation proteomics following cellular transformation of rat primary mesenchymal precursor. Among them, SERPINE1 mRNA binding protein 1 (SERBP1) deacetylation is increased and required for KSHV-induced cellular transformation. Mechanistically, KSHV-encoded viral interleukin-6 (vIL-6) promotes SIRT3 deacetylation of SERBP1, preventing its binding to and protection of lipoyltransferase 2 (Lipt2) mRNA from mRNA degradation resulting in ferroptosis. Consequently, a SIRT3-specific inhibitor, 3-TYP, suppresses KSHV-induced cellular transformation by inducing ferroptosis. Our findings unveil novel roles of vIL-6 and SERBP1 deacetylation in regulating ferroptosis and KSHV-induced cellular transformation, and establish the vIL-6-SIRT3-SERBP1-ferroptosis pathways as a potential new therapeutic target for KSHV-associated cancers. Author summary: Ferroptosis has been implicated in viral infections and the development of cancers, however, its role in oncogenic Kaposi's sarcoma-associated herpesvirus (KSHV)-induced cancers is still unknown. Although abnormal protein lysine acetylation modification has been strongly implicated in tumorigenesis, the exact role of this modification in KSHV-induced cell transformation remains elusive. Our study uncovers the reduction of acetylation of SERPINE1 mRNA binding protein 1 (SERBP1), which is required for KSHV-induced cellular transformation. KSHV-encoded viral interleukin-6 (vIL-6) promotes SIRT3 deacetylation of SERBP1, preventing its binding to and protection of lipoyltransferase 2 (Lipt2) mRNA from mRNA degradation resulting in ferroptosis. A SIRT3-specific inhibitor, 3-TYP, induces ferroptosis and inhibits survival of KSHV-transformed cells. These findings define a novel mechanism contributing to KSHV-induced cellular transformation and provide a rationale for therapeutically targeting lysine acetylation and the associated enzyme for infectious diseases. [ABSTRACT FROM AUTHOR]