AUTHOR=Lu Chenchen , Li Zhiqing , Zhang Wenchang , Guo Hao , Lan Weiqun , Shen Guanwang , Xia Qingyou , Zhao Ping 

TITLE=SUMOylation of Translationally Regulated Tumor Protein Modulates Its Immune Function

JOURNAL=Frontiers in Immunology

VOLUME=13

YEAR=2022

URL=https://www.frontiersin.org/journals/immunology/articles/10.3389/fimmu.2022.807097

DOI=10.3389/fimmu.2022.807097

ISSN=1664-3224

ABSTRACT=<p>Translationally controlled tumor protein (TCTP) is a highly conserved protein possessing numerous biological functions and molecular interactions, ranging from cell growth to immune responses. However, the molecular mechanism by which TCTP regulates immune function is largely unknown. Here, we found that knockdown of <italic>Bombyx mori</italic> translationally controlled tumor protein (<italic>BmTCTP</italic>) led to the increased susceptibility of silkworm cells to virus infection, whereas overexpression of <italic>BmTCTP</italic> significantly decreased the virus replication. We further demonstrated that <italic>BmTCTP</italic> could be modified by SUMOylation molecular BmSMT3 at the lysine 164 <italic>via</italic> the conjugating enzyme BmUBC9, and the stable SUMOylation of <italic>BmTCTP</italic> by expressing <italic>BmTCTP</italic>-BmSMT3 fusion protein exhibited strong antiviral activity, which confirmed that the SUMOylation of <italic>BmTCTP</italic> would contribute to its immune responses. Further work indicated that <italic>BmTCTP</italic> is able to physically interact with interleukin enhancer binding factor (ILF), one immune molecular, involved in antivirus, and also induce the expression of <italic>BmILF</italic> in response to virus infection, which in turn enhanced antiviral activity of <italic>BmTCTP</italic>. Altogether, our present study has provided a novel insight into defending against virus <italic>via BmTCTP</italic> SUMOylation signaling pathway and interacting with key immune molecular in silkworm.</p>