Distinct regions of Praja-1 E3 ubiquitin-protein ligase selectively bind to docosahexaenoic acid-containing phosphatidic acid and diacylglycerol kinase δ
Distinct regions of Praja-1 E3 ubiquitin-protein ligase selectively bind to docosahexaenoic acid-containing phosphatidic acid and diacylglycerol kinase δ
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Praja-1 E3 泛素蛋白连接酶的不同区域选择性结合含有二十二碳六烯酸的磷脂酸和二酰甘油激酶 δ
DOI：
10.1016/j.bbalip.2022.159265
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发表时间：
2023
期刊：
影响因子：
--
通讯作者：
Sakane Fumio
中科院分区：
文献类型：
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作者：
Numagami Yuki;Hoshino Fumi;Murakami Chiaki;Ebina Masayuki;Sakane Fumio
1-硬脂酰基-2-二十二碳六烯酰(18：0/22：6)-磷脂酸(PA)与Praja-1 E3泛素蛋白连接酶(全长：615aa)相互作用并激活，泛素化和降解5-羟色胺转运体(SERT)。SERT调节5-羟色胺能系统活动，是抑郁症、自闭症、强迫症、精神分裂症和阿尔茨海默病的治疗靶点。此外，二酰甘油激酶δ2(全长：1214aa)除了与序列反应外，还与PraJA-1相互作用，产生18：0/22：6-PA，结合并激活PraJA-1。在本研究中，我们更详细地研究了PARJA-1与18：0/22：6-PA和DGKδ2的相互作用。我们首次发现Praja-1的N末端1/3区域(aa1-224)与18：0/22：6-PA结合，该区域的Lys141是与18：0/22：6-PA结合的关键。反之，PARJA-1的C端催化结构域(AA446-615)与DGKδ2相互作用。此外，DGKδ2的催化结构域(AA309-466)的N端部分与PARJA-1紧密结合。此外，DGKδ2含有Pleckstrin同源区和C1区(aa1-308)的N-末端区域和催化结构域(aa762-939)的C-末端部分与PraJA-1弱相关。综上所述，这些结果揭示了PARJA-1的N末端(AA1-224)和C末端(AA446-615)区域以及DGKδ2催化区的N-末端(AA309-466)作为调节域的新功能。此外，DGKδ2-PARJA-1-SERT杂三聚体很可能位于DGKδ2的18：0/22：6-PA产生催化结构域、PARJA-1的18：0/22：6-PA结合调节区、PARJA-1的泛素蛋白连接酶催化结构域以及含有泛素化受体位点的SERT C末端区域。
1-Stearoyl-2-docosahexaenoyl (18:0/22:6)-phosphatidic acid (PA) interacts with and activates Praja-1 E3 ubiquitin-protein ligase (full length: 615 aa) to ubiquitinate and degrade the serotonin transporter (SERT). SERT modulates serotonergic system activity and is a therapeutic target for depression, autism, obsessive-compulsive disorder, schizophrenia and Alzheimer's disease. Moreover, diacylglycerol kinase (DGK) δ2 (full length: 1214 aa) interacts with Praja-1 in addition to SERT and generates 18:0/22:6-PA, which binds and activates Praja-1. In the present study, we investigated the interaction of Praja-1 with 18:0/22:6-PA and DGKδ2 in more detail. We first found that the N-terminal one-third region (aa 1–224) of Praja-1 bound to 18:0/22:6-PA and that Lys141 in the region was critical for binding to 18:0/22:6-PA. In contrast, the C-terminal catalytic domain of Praja-1 (aa 446–615) interacted with DGKδ2. Additionally, the N-terminal half of the catalytic domain (aa 309–466) of DGKδ2 intensely bound to Praja-1. Moreover, the N-terminal region containing the pleckstrin homology and C1 domains (aa 1–308) and the C-terminal half of the catalytic domain (aa 762–939) of DGKδ2 weakly associated with Praja-1. Taken together, these results reveal new functions of the N-terminal (aa 1–224) and C-terminal (aa 446–615) regions of Praja-1 and the N-terminal half of the catalytic region (aa 309–466) of DGKδ2 as regulatory domains. Moreover, it is likely that the DGKδ2–Praja-1–SERT heterotrimer proximally arranges the 18:0/22:6-PA-producing catalytic domain of DGKδ2, the 18:0/22:6-PA-binding regulatory domain of Praja-1, the ubiquitin-protein ligase catalytic domain of Praja-1 and the ubiquitination acceptor site-containing SERT C-terminal region.