biostudies-literatureSowders JMDirectorate for Biological SciencesNational Institute of Food and AgricultureNIGMS NIH HHS1086-1101https://www.ebi.ac.uk/biostudies/studies/S-EPMC11096078biostudies-literatureUnknown118(4)Extracellular ATP (eATP) is a key signaling molecule that plays a pivotal role in plant growth and defense responses. The receptor P2K1 is responsible for perceiving eATP and initiating its signaling cascade. However, the signal transduction mechanisms downstream of P2K1 activation remain incompletely understood. We conducted a comprehensive analysis of the P2K1 interactome using co-immunoprecipitation-coupled tandem mass spectrometry, leading to the identification of 121 candidate proteins interacting with P2K1. In silico analysis narrowed down the candidates to 47 proteins, including Ca²⁺-binding proteins, ion transport-related proteins, and receptor kinases. To investigate their involvement in eATP signaling, we employed a screening strategy based on changes in gene expressioThe Plant journal : for cell and molecular biologyCPK28 is a modulator of purinergic signaling in plant growth and defense.PMC110960781015621IOS‐1557813IOS-1557813T32 GM008336Tanaka KSowders JMJewell JBfalseCPK28 is a modulator of purinergic signaling in plant growth and defense.Extracellular ATP (eATP) is a key signaling molecule that plays a pivotal role in plant growth and defense responses. The receptor P2K1 is responsible for perceiving eATP and initiating its signaling cascade. However, the signal transduction mechanisms downstream of P2K1 activation remain incompletely understood. We conducted a comprehensive analysis of the P2K1 interactome using co-immunoprecipitation-coupled tandem mass spectrometry, leading to the identification of 121 candidate proteins interacting with P2K1. In silico analysis narrowed down the candidates to 47 proteins, including Ca²⁺-binding proteins, ion transport-related proteins, and receptor kinases. To investigate their involvement in eATP signaling, we employed a screening strategy based on changes in gene expressio2024-01-01T00:00:00Z2024 May2025-06-27T03:05:25.741Z2025-06-27T03:05:25.741ZS-EPMC110960783830859710.1111/tpj.16656