T-cell receptor (TCR) signaling is essential for the function of T cells and negatively regulated by the E3 ubiquitin-protein ligases CBL and CBLB Here, we combined mouse genetics and affinity purification coupled to quantitative mass spectrometry to monitor the dynamics of the CBL and CBLB signaling complexes that assemble in normal T cells over 600 seconds of TCR stimulation. We identify most previously known CBL and CBLB interacting partners, as well as a majority of proteins that have not yet been implicated in those signaling complexes. We exploit correlations in protein association with CBL and CBLB as a function of time of TCR stimulation for predicting the occurrence of direct physical association between them. By combining co-recruitment analysis with biochemical analysis, we demonstrated that the CD5 transmembrane receptor constitutes a key scaffold for CBL- and CBLB-mediated ubiquitylation following TCR engagement. Our results offer an integrated view of the CBL and CBLB signaling complexes induced by TCR stimulation and provide a molecular basis for their negative regulatory function in normal T cells.

中文翻译：

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对原代 T 细胞中 CBL 和 CBLB 信号体的共同募集分析确定 CD5 是 TCR 诱导的泛素化的关键调节因子。

T 细胞受体 (TCR) 信号传导对 T 细胞的功能至关重要，并受 E3 泛素蛋白连接酶 CBL 和 CBLB 负调控和 CBLB 信号复合物，在 600 秒的 TCR 刺激下在正常 T 细胞中组装。我们确定了大多数以前已知的 CBL 和 CBLB 相互作用伙伴，以及大多数尚未涉及这些信号复合物的蛋白质。我们利用蛋白质与 CBL 和 CBLB 的相关性作为 TCR 刺激时间的函数来预测它们之间直接物理关联的发生。通过将联合招募分析与生化分析相结合，我们证明了 CD5 跨膜受体构成了 TCR 参与后 CBL 和 CBLB 介导的泛素化的关键支架。我们的结果提供了 TCR 刺激诱导的 CBL 和 CBLB 信号复合物的综合视图，并为它们在正常 T 细胞中的负调节功能提供了分子基础。