Mechanisms underlying the polar localization and ER accumulation of rice ammonium transporter1

2023 Fiscal Year Final Research Report

• Project/Area Number: 22K14805
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 38010:Plant nutrition and soil science-related
• Research Institution: Okayama University
• Principal Investigator: Konishi Noriyuki 岡山大学, 資源植物科学研究所, 助教 (20866959)
• Project Period (FY): 2022-04-01 – 2024-03-31
• Keywords: アンモニウム / イネ / アンモニウム輸送体 / 極性局在 / 小胞体蓄積 / リン酸化 / 翻訳後制御

Outline of Final Research Achievements

Ammonium is a major nitrogen source for paddy-growing rice, and three ammonium transporter1 (AMT1) members are responsible for its uptake. In rice, AMT1 members polarly localize at the distal side of the plasma membrane, and they accumulate in ER after ammonium supply. However, the physiological significance and mechanisms underlying these posttranslational regulations are poorly understood.
Here, we analyzed the localization of various AMT1;1 deletion variants and point-mutated AMT1;2 variants to investigate the region involved in their polar localization and ER accumulation. Overall, this analysis indicates that 1) phosphorylations at the C-terminal cytosolic region of AMT1;2 was not required for its polar localization, 2) the 13 amino acid region of AMT1;1 C-terminus was involved in its membrane trafficking. Furthermore, by co-immunoprecipitation, we identify several interacting proteins of AMT1;1 and AMT1;2 as potential regulators of their posttranslational regulations.

Free Research Field

植物栄養学

Academic Significance and Societal Importance of the Research Achievements

本研究では、AMT1のイネに特徴的な翻訳後制御機構の解明に向けての端緒をつかむことができた。今後、イネの窒素利用効率の向上に資する発見につながると期待される。