An essential role of sumoylation in T cell synapse organization and T cell activation discovered by Yingqiu Li Group
Source:Yingqiu Li
2016-03-15
Dr. Yingqiu Li and colleagues, School of Life Sciences, Sun Yat-sen University, have reported that a kind of posttranslational modification, SUMO modification, is required for T cell immunological synapse formation and T cell activation. This report entitled “TCR-induced sumoylation of the kinase PKC-θ controls T cell synapse organization and T cell activation” was published on Nature Immunology.

T cells are a central component of the adaptive immune system. When the TCR and its coreceptors (e.g., CD28, CD4 and CD8) are engaged by cognate antigens and costimulatory ligands presented by antigen-presenting cells (APCs), an immunological synapse is formed at the T cell–APC contact site. The mature immunological synapse, which provides a platform for appropriate TCR signal transduction, segregates into a TCR–PKC-θ–rich central supramolecular activation cluster (cSMAC), an integrin-rich peripheral SMAC, and a distal SMAC. In this report, the scientists found that the kinase PKC-θ was sumoylated upon costimulation with antigen or via the TCR plus the coreceptor CD28. They identified the SUMO E3 ligase PIASxβ as a ligase for PKC-θ and revealed that sumoylation ofPKC-θ was essential for T cell activation. Desumoylation did not affect the catalytic activity of PKC-θ but inhibited the association of CD28 with PKC-θ and filamin A and impaired the assembly of a mature immunological synapse and central co-accumulation of PKC-θ and CD28. Their findings demonstrate that sumoylation controls TCR-proximal signaling and that sumoylation of PKC-θ is essential for the formation of a mature immunological synapse and T cell activation.

Article: Xu-Dong Wang#, Yu Gong#, Zhi-Long Chen#, Bei-Ni Gong#, Ji-JiXie, Chuan-Qi Zhong, Qi-Long Wang, Liang-HuiDiao, Anlong Xu, Jiahuai Han, Amnon Altman &Yingqiu Li*. TCR-induced sumoylation of the kinase PKC-theta controls T cell synapse organization and T cell activation.Nat Immunol. 2015 Nov;16(11):1195-203. doi: 10.1038/ni.3259. Epub 2015 Sep 21.