1H, 13C, 15N chemical shift assignments of SHP2 SH2 domains in complex with PD-1 immune-tyrosine motifs

Anti-Tumor Potential of Post-Translational Modifications of PD-1

Programmed cell death protein-1 (PD-1) is a vital immune checkpoint molecule. The location, stability, and protein-protein interaction of PD-1 are significantly influenced by post-translational modification (PTM) of proteins. The biological information of PD-1, including its gene and protein structures and the PD-1/PD-L1 signaling pathway, was briefly reviewed in this review. Additionally, recent research on PD-1 post-translational modification, including the study of ubiquitination, glycosylation, phosphorylation, and palmitoylation, was summarized, and research strategies for PD-1 PTM drugs were concluded. At present, only a part of PD-1/PD-L1 treated patients (35-45%) are benefited from immunotherapies, and novel strategies targeting PTM of PD-1/PD-L1 may be important for anti-PD-1/PD-L1 non-responders (poor responders).

Targeting protein phosphatases in cancer immunotherapy and autoimmune disorders

Protein phosphatases act as key regulators of multiple important cellular processes and are attractive therapeutic targets for various diseases. Although extensive effort has been dedicated to phosphatase-targeted drug discovery, early expeditions for competitive phosphatase inhibitors were plagued by druggability issues, leading to the stigmatization of phosphatases as difficult targets. Despite challenges, persistent efforts have led to the identification of several drug-like, non-competitive modulators of some of these enzymes - including SH2 domain-containing protein tyrosine phosphatase 2, protein tyrosine phosphatase 1B, vascular endothelial protein tyrosine phosphatase and protein phosphatase 1 - reigniting interest in therapeutic targeting of phosphatases. Here, we discuss recent progress in phosphatase drug discovery, with emphasis on the development of selective modulators that exhibit biological activity. The roles and regulation of protein phosphatases in immune cells and their potential as powerful targets for immuno-oncology and autoimmunity indications are assessed.

NMR Methods to Study the Dynamics of SH2 Domain-Phosphopeptide Complexes

Nuclear magnetic resonance (NMR) spectroscopy is the method of choice for studying the dynamics of biological macromolecules in solution. By exploiting the intricate interplay between the effects of protein motion (both overall rotational diffusion and internal mobility) and nuclear spin relaxation, NMR allows molecular motion to be probed at atomic resolution over a wide range of timescales, including picosecond (bond vibrations and methyl-group rotations), nanosecond (loop motions and rotational diffusion), and microsecond-millisecond (ligand binding, allostery). In this chapter, we describe different NMR pulse schemes (R1, R1ρ, heteronuclear NOE, and CPMG relaxation dispersion) to characterize the dynamics of SH2 domains. As an example, we use the N-SH2 domain of protein tyrosine phosphatase SHP2 in complex with two phosphopeptides derived from immune checkpoint receptor PD-1 (ITIM and ITSM).