Phosphorylation analysis of the Hippo-YAP pathway using Phos-tag

Phosphorylation is an essential regulatory mechanism in cells that modifies diverse substrates, such as proteins, carbohydrates, lipids, and nucleotides. Protein phosphorylation regulates function, subcellular localization, and protein-protein interactions. Protein kinases and phosphatases catalyze this reversible mechanism, subsequently influencing signal transduction. The dysregulation of protein phosphorylation leads to many diseases, such as cancer, neurodegenerative diseases, and metabolic diseases. Therefore, analyzing the phosphorylation status and identifying protein phosphorylation sites are critical for elucidating the biological functions of specific phosphorylation events. Unraveling the critical phosphorylation events associated with diseases and specific signaling pathways is promising for drug discovery. To date, highly accurate and sensitive approaches have been developed to detect the phosphorylation status of proteins. In this review, we discuss the application of Phos-tag to elucidate the biological functions of Hippo pathway components, with emphasis on the identification and quantitation of protein phosphorylation under physiological and pathological conditions. SIGNIFICANCE: We here provide a comprehensive overview of Phos-tag technique-based strategies to identify phosphorylated proteins at the cellular level in the Hippo-YAP pathway that comprises a major driving force for cellular homeostasis. We clarify the links of applying Phos-tag in elucidating the biological functions of the Hippo pathway components with particular attention to the identification and quantitation of protein phosphorylation under physiological and pathological conditions. We believe that our paper will make a significant contribution to the literature because these detailed phosphorylation modifications and functional diversity of the Hippo pathway components in physiological and pathological processes are only beginning to come to the fore, highlighting the potential for discovering new therapeutic targets. Moreover, this line of research can provide further insight into the inextricable link between phos-tag applications as a molecular tool and cellular signaling modality, offering new directions for an integrated research program toward understanding cellular regulation at the molecular level. Given the broad research and practical applications, we believe that this paper will be of interest to the readership of your journal.