Protein tyrosine phosphatase non-receptor type 13-Signal transducer and activator of transcription 1 protein-protein interface (PTPN13-STAT1 PPI) (PTPN13-STAT1 PPI)

The PTPN13-STAT1 protein-protein interface is a critical regulatory site where the non-receptor protein tyrosine phosphatase 13 (PTPN13, also known as FAP-1) interacts with and dephosphorylates the Signal Transducer and Activator of Transcription 1 (STAT1) [1, 2]. This dephosphorylation at the Tyr701 residue terminates STAT1 signaling, which is essential for the IFNγ-mediated induction of interferon regulatory factor 1 (IRF1) and major histocompatibility complex (MHC) class I molecules [1, 2]. In cancers such as colorectal cancer, particularly those with APC mutations, this interface is exploited to suppress antigen presentation and facilitate immune evasion [1, 2, 3]. Therapeutic strategies targeting this interface, such as the experimental APC11 peptide, aim to block the PTPN13-STAT1 interaction to restore STAT1 phosphorylation and enhance anti-tumor immunity [1, 2]. However, PTPN13 is a multi-functional protein that also regulates Fas-mediated apoptosis and stabilizes cell-cell junctions through desmosome formation [3, 8, 10]. Consequently, achieving high specificity for the STAT1 interaction is a primary challenge to avoid disrupting other homeostatic functions of the phosphatase [12].

Other names

Fas-associated phosphatase 1-Signal transducer and activator of transcription 1 interfacePTPL1-STAT1 interactionPTP-BAS-STAT1 interfacePTP-BL-STAT1 interfaceFAP-1-STAT1 PPI

Inhibition of the protein-protein interaction between PTPN13 and STAT1 to prevent dephosphorylation of STAT1 at Tyr701, thereby restoring IFNγ-mediated immune signaling.