Mass spectrometry analysis of EphA2-interacting proteins, EphA2 ubiquitination, DCAF15 acetylation, and SIRT1 phosphorylation in Streptococcus suis-induced blood-brain barrier disruption

This dataset contains mass spectrometry (MS) analyses performed to investigate the molecular mechanisms by which Streptococcus suis (S. suis) disrupts the blood-brain barrier (BBB) through targeting Ephrin type-A receptor 2 (EphA2). The submitted data includes four independent MS datasets: Affinity purification-mass spectrometry (AP-MS) to identify host proteins that interact with EphA2 upon S. suis infection, which led to the discovery of the E3 ligase DCAF15. Liquid chromatography-tandem MS (LC-MS/MS) analysis of immunopurified EphA2 to map the specific sites of S. suis-induced ubiquitination on EphA2 (identifying K646, K649, and K754 as major sites for K48- and K63-linked ubiquitin chains). LC-MS/MS analysis of immunopurified DCAF15 to identify the specific acetylation sites on DCAF15 (K552 and K581) that regulate its function and interaction with EphA2. LC-MS/MS analysis of immunopurified SIRT1 to confirm the specific phosphorylation site on SIRT1 (S48) induced by the bacterial serine/threonine kinase (STK). Collectively, these MS-based site-mapping experiments reveal a novel bacterial strategy where S. suis STK phosphorylates SIRT1 at S48, leading to deacetylation of DCAF15 at K552/K581, which in turn promotes ubiquitination of EphA2 at K646/K649/K754 and its subsequent degradation, thereby exacerbating BBB disruption. These data provide crucial proteomic evidence for the proposed mechanistic pathway.