Abstract
OsPti1a is a negative regulator of defense signaling in rice. Previously, we showed that OsPti1a was mainly localized to plasma membrane through lipid modification of its N-terminus. Additionally, deletion of the N-terminal 10 amino acid of OsPti1a compromised its function in the complementation analysis, suggesting that localization of OsPti1a to plasma membrane is indispensable for negative regulation of disease resistance. Gel-filtration analysis revealed that OsPti1a formed a large complex about 200-300 kDa. However, deletion of the N-terminus of OsPti1a decreased molecular size of the complex. This result suggests that appropriate complex formation of OsPti1a at the plasma membrane is required for the function of OsPti1a in disease resistance. To characterize this complex, OsPti1a-interacting proteins were isolated by co-IP and identified by mass spectrometry method. We confirmed some of the candidates interacted with OsPti1a in yeast. The analysis of these candidates will help us to understand the molecular function of OsPti1a in disease resistance.
