Regulatory mechanism of phospholipase D activity and its physiological role in rat parotid glands

大鼠腮腺磷脂酶D活性的调节机制及其生理作用

• 批准号: 16591875
• 负责人: KAMIYA Masako
• 金额: $ 2.36万
• 依托单位: Asahi University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2004
• 资助国家: 日本
• 起止时间: 2004 至 2007
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-16591875/
• 关键词: signal transduction; phospholipase D; phosphoinositide kinase; phospholipase A_2; apical plasma membranes; secretory granules; phosphatidic aicid; phosnhatidylinosito1-4, 5-diphosnhate; イノシトールリン脂質; 細胞骨格; ジアシルグリセロール; 脂肪酸

In this study, to clarify mechanisms controlling PLD activity at the exocytotic site, we investigated the effects of various factors on the PLD activity associated with apical plasma membranes from rat parotid glands. We also investigated the physiological relationship between PLD activation and saliva secretion. An outline of the results is as follows :1. The mechanism of PLD activation :PLD was activated synergistically by free fatty acids and phosphatidylinositol-4, 5-diphosphate (PIP_2), whereas it was inhibited by phosphatidylinositol(PI). PLD was also activated by phosphatidic acid(PA), which is produced by PLD itself. These results suggest that the regulation of PLD activity is complex, and at least three factors act in a synergistic manner as follows: (1) the production of fatty acids by phospho-lipase A_2, (2) a shift in the balance from PI to PIP_2 and (3) a product-mediated positive feedback loop.2. Signal cross-talk between PLD and phosphoinositide kinases :Interestingly, the synthesis of PIP_2 by phosphoinositide 5-kinase (PIP5K) was also activated by PLD-derived PA. On the contrary, PA inhibited PI kinase, which supplies the substrate to PIP5K. On the other hand, it was thought that PIP tended to accumulate in secretory granular membranes in the presence or absence of PA. These results suggest that positive feed-forward regulation is achieved through the stimulation of PLD by PIP5K-derived PIP_2, and of PIP5K by PLD-derived PA. At the site of exocytosis, secretory granular membranes may supply the PIP5K substrate.3. The correlation of PLD signaling with exocytosis :When the membranes were treated with PLD in the in vitro fusion system, fusion was facilitated in proportion to the PA content of the membrane. Moreover, when PIP2 was introduced directly into the parotid cells, the amylase secretion stimulated by isoproterenol was increased.These results suggest that PLD and PIP5K act together to induce some physiological function, such as exocytosis.

在这项研究中，以澄清机制控制PLD活性在胞吐网站，我们研究了各种因素对PLD活性与大鼠腮腺顶端质膜的影响。我们还研究了PLD激活和唾液分泌之间的生理关系。主要研究结果如下：1.磷脂酶D激活机制：磷脂酰肌醇（PI）抑制磷脂酶D的激活，而游离脂肪酸和磷脂酰肌醇-4，5-二磷酸（PIP_2）协同激活磷脂酶D。磷脂酶D自身产生的磷脂酸（PA）也能激活磷脂酶D。这些结果表明，PLD活性的调节是复杂的，至少有三个因素以协同的方式起作用：（1）磷脂酶A_2产生脂肪酸;（2）平衡从PI向PIP_2的转移;（3）产物介导的正反馈环。PLD与磷脂酰肌醇激酶之间的信号串扰：有趣的是，磷脂酰肌醇5-激酶（PIP 5 K）合成PIP_2也被PLD衍生的PA激活。相反，PA抑制PI激酶，PI激酶为PIP 5 K提供底物。另一方面，有人认为，PIP倾向于积累在分泌颗粒膜在PA的存在或不存在。这些结果表明，正前馈调节是通过PIP 5 K衍生的PIP_2刺激PLD和PIP 5 K衍生的PA刺激PLD实现的。在胞吐部位，分泌颗粒膜可能提供PIP 5 K底物。PLD信号与胞吐的相关性：当在体外融合系统中用PLD处理膜时，膜的PA含量成比例地促进融合。此外，当PIP 2直接导入腮腺细胞时，异丙肾上腺素刺激的淀粉酶分泌增加，这些结果表明PLD和PIP 5 K共同作用，诱导一些生理功能，如胞吐。

项目成果

The significance of cytoskeleton in exocytosis : Control of apical plasma membranes-evoked amylase release from secretory granules isolated from the rat parotid glands

细胞骨架在胞吐作用中的意义：控制顶端质膜引起的从大鼠腮腺分离的分泌颗粒释放淀粉酶

• 发表时间: 2008
• 期刊: J. Gifu Dent. Soc.(Reviewed) 34(3)
• 作者: Yasunaga Kameyama;et. al.
• 通讯作者: et. al.

The significance of cytoskeleton in exocytosis: Control of apical plasma membranes-evoked amylase release from secretory granules isolated from the rat parotid glands

细胞骨架在胞吐作用中的意义：控制顶端质膜引起的从大鼠腮腺分离的分泌颗粒释放淀粉酶

• 发表时间: 2008
• 期刊: J. Gifu Dent. Soc. 34
• 作者: Yasunaga Kameyama;et. al.;Yasunaga Kameyama;Yasunaga Kameyama
• 通讯作者: Yasunaga Kameyama

The significance of cytoskeleton in exocytosis:Control of apical plasma membranes-evoked amylase release from secretory granules isolated from the rat parotid glands

细胞骨架在胞吐作用中的意义：控制顶端质膜引起的大鼠腮腺分泌颗粒释放淀粉酶

• 发表时间: 2008
• 期刊: J.Gifu Dent.Soc. 34
• 作者: T.Nagano;S.Oida;H.Ando;K.Gomi;T.Arai;M.Fukae;Koji Yashiro;Yasunaga Kameyama;Yasunaga Kameyama
• 通讯作者: Yasunaga Kameyama

Enhancemen of acyl-CoA : 1-acyl-sn-glycerol-3-phosphocholine acyltranseferase activity in the microsomes from rat submandibular gland during the growth

酰基辅酶A的增强：生长过程中大鼠颌下腺微粒体中1-酰基-sn-甘油-3-磷酸胆碱酰基转移酶活性

• 发表时间: 2007
• 期刊: J. Gifu Dent. Soc. 34(3)(Reviewed)
• 作者: Yasunaga Kameyama;et. al.
• 通讯作者: et. al.

イノシトールリン脂質代謝系のホスホリパーゼD代謝産物による活性調節

磷脂酶 D 代谢物对肌醇磷脂代谢系统活性的调节

• 发表时间: 2006
• 作者: Masako Mizuno-Kamiya;et. al.;神谷 真子
• 通讯作者: 神谷 真子