[PDF][PDF] Selective autophagy of the adaptor protein Bcl10 modulates T cell receptor activation of NF-κB

S Paul, AK Kashyap, W Jia, YW He, BC Schaefer - Immunity, 2012 - cell.com
S Paul, AK Kashyap, W Jia, YW He, BC Schaefer
Immunity, 2012cell.com
The adaptor protein Bcl10 is a critically important mediator of T cell receptor (TCR)-to-NF-κB
signaling. Bcl10 degradation is a poorly understood biological phenomenon suggested to
reduce TCR activation of NF-κB. Here we have shown that TCR engagement triggers the
degradation of Bcl10 in primary effector T cells but not in naive T cells. TCR engagement
promoted K63 polyubiquitination of Bcl10, causing Bcl10 association with the autophagy
adaptor p62. Paradoxically, p62 binding was required for both Bcl10 signaling to NF-κB and …
Summary
The adaptor protein Bcl10 is a critically important mediator of T cell receptor (TCR)-to-NF-κB signaling. Bcl10 degradation is a poorly understood biological phenomenon suggested to reduce TCR activation of NF-κB. Here we have shown that TCR engagement triggers the degradation of Bcl10 in primary effector T cells but not in naive T cells. TCR engagement promoted K63 polyubiquitination of Bcl10, causing Bcl10 association with the autophagy adaptor p62. Paradoxically, p62 binding was required for both Bcl10 signaling to NF-κB and gradual degradation of Bcl10 by autophagy. Bcl10 autophagy was highly selective, as shown by the fact that it spared Malt1, a direct Bcl10 binding partner. Blockade of Bcl10 autophagy enhanced TCR activation of NF-κB. Together, these data demonstrate that selective autophagy of Bcl10 is a pathway-intrinsic homeostatic mechanism that modulates TCR signaling to NF-κB in effector T cells. This homeostatic process may protect T cells from adverse consequences of unrestrained NF-κB activation, such as cellular senescence.
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