Protein–protein interactions of tandem affinity purification‐tagged protein kinases in rice

Summary Forty‐one rice cDNAs encoding protein kinases were fused to the tandem affinity purification (TAP) tag and expressed in transgenic rice plants. The TAP‐tagged kinases and interacting proteins were purified from the T1 progeny of the transgenic rice plants and identified by mass spectrometry. Ninety‐five percent of the TAP‐tagged kinases were recovered. Fifty‐six percent of the TAP‐tagged kinases were found to interact with other rice proteins. A number of these interactions were consistent with known protein complexes found in other species, validating the TAP‐tag method in rice plants. Phosphorylation sites were identified on four of the kinases that interacted with either 14‐3‐3 proteins or cyclins.