Regulation of inositol phospholipid-pelated 2nd messengers

肌醇磷脂包裹的第二信使的调节

• 批准号: 07044216
• 负责人: KONDO Hisatake
• 金额: $ 7.3万
• 依托单位: Tohoku University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for international Scientific Research
• 财政年份: 1995
• 资助国家: 日本
• 起止时间: 1995 至 1996
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-07044216/
• 关键词: PI-turnover; DG-kinase; PA-phosphatase; gene cloning; arachidonic acid; molecular heterogeneity; PIキナーゼ; ホスファチジン酸ホスファターゼ; 遺伝子発現局在; 脳; 網膜; ラット; ジアシルグリセロールキナーゼ; イノシトールリン脂質; 核局在; ショウジョウバエ

Phosphoinositides (PI) turnover produces second messengers such as diacylglycerol (DG) and inositol triphosphate in response to external stimuli. DG acts as an activator of several forms of protein kinase C and is converted to phosphatidic acid (PA) by DG kinase. On the other hand, PA is cleaved from phosphatidylcholine and converted to DG by PA phosphatase. PA and its metabolic derivative, lysophosphatidic acid, are potent mitogens and activators. Therefore, DG kinase and PA phosphatase play crucial roles in regulation of the relative concentration of DG and PA,both of which serve as signal mediators as well as intermediates of glycerolipid synthesis.The present study disclosed for the first time the heterogeneity of DG kinase in terms of molecular structure, biochemical characteristics and gene expression localization in the brain and clarified the molecular identity of PA phosphatase : Four subtypes of DG kinase (termed type I-IV) were identified by H.Kondo (Head investigator) and h … More is group, its fifth subtype (type delta) was identified by H.Kanoh (co-investigator), its sixth subtype (type thita) by W.J.van Blitterswijk (co-investigator), its seventh by J.A.Glomset (co-investigator), while PA phosphatase (type II) was identified by H.Kanoh. The DG kinase type I is of soluble form and localized in the oligodendrocyte, but not neurons, and the absence of its expression is seen in the brain of myelin-deficient (shiverer) mice, suggesting the role in formation and maintenance of the myelin. The type II DG kinase is of membrane-associated from and localized in the medium-spiny neurons, neurons in the nucleus accumbens and olfactory tubercle, and in the endocrine cells of the pituitary inermediate lobe, suggesting the involvement in the dopaminergic transmission. The type III is localized dominantly in the Purkinje neurons and substantially in the granule cells of the cerebellum, suggesting its role in the cerebellar motor-control. The type IV is localized in the cerebral and cebellar cortical neurons, but peculiar in the molecular structure : while the former three contain two EF-hand and zinc-finger motifs in addition to the ATP-binding domain, the type IV contains no EF-hand motifs, but possesses ankyrin-like repeats. This structure has a high homology to rdgA (a gene of Drosophila inducing the retinal degeneration). A nuclear targeting motif is also contained and the transfection of this cDNA into the fibroblast results in localization of its protein in the nucleus, suggesting its role in the regulation of transcription. The delta type contains a pleckstrin homology domain and a DPH C-terminal tail homology domain, while the thita type contains three cysteine-rich domains, a proline-rich region and a pleckstrin homology domain with overlapping ras-associating domain. The DG kinase subtype by J.A.Glomset is a membrane-bound and selectively phosphrylates arachidonoyl-DG,indicating that this is specific in the PI turnover. The type II PA phosphatase is membrane-bound and its N-terminal sequence is conserved in the partial cDNA of hic53, a H O -inducible gene. Less

磷脂酰肌醇（PI）周转产生第二信使，如二酰基甘油（DG）和肌醇三磷酸响应外部刺激。DG作为几种形式的蛋白激酶C的激活剂，并通过DG激酶转化为磷脂酸（PA）。另一方面，PA从磷脂酰胆碱裂解并通过PA磷酸酶转化为DG。PA及其代谢衍生物溶血磷脂酸是有效的有丝分裂原和激活剂。因此，DG激酶和PA磷酸酶在调节DG和PA的相对浓度中起着至关重要的作用，两者都是信号介质和甘油脂合成的中间体。本研究首次揭示了DG激酶在分子结构、生化特性和脑内基因表达定位方面的异质性，并阐明了PA磷酸酶的分子身份：DG激酶的四种亚型（称为I-IV型）由H.Kondo（首席研究员）和H. ...更多信息 第五种亚型（delta型）由H.Kanoh（共同研究者）鉴定，第六种亚型（thita型）由W. J.货车Blitterswijk（共同研究者）鉴定，第七种亚型由J.A.Glomset（共同研究者）鉴定，而PA磷酸酶（II型）由H. Kanoh鉴定。DG激酶I型是可溶性形式，定位于少突胶质细胞中，但不定位于神经元中，并且在髓鞘缺陷（颤抖）小鼠的脑中观察到其表达的缺失，表明其在髓鞘形成和维持中的作用。Ⅱ型DG激酶是膜相关的，并定位于中棘神经元，神经元在丘脑核和嗅结节，并在垂体中间叶的内分泌细胞，表明参与多巴胺能传递。III型主要定位于浦肯野神经元和小脑颗粒细胞，表明其在小脑运动控制中的作用。IV型定位于大脑和小脑皮质神经元中，但在分子结构上独特：前三种除了ATP结合结构域外还含有两个EF-手和锌指基序，而IV型不含EF-手基序，但具有锚定样重复序列。该结构与rdgA（果蝇属诱导视网膜变性的基因）具有高度同源性。还含有核靶向基序，并且将该cDNA转染到成纤维细胞中导致其蛋白质定位在细胞核中，表明其在转录调节中的作用。delta型含有一个pleckstrin同源结构域和一个DPH C-末端尾部同源结构域，而thita型含有三个富含半胱氨酸的结构域、一个富含脯氨酸的区域和一个具有重叠ras-缔合结构域的pleckstrin同源结构域。由J.A.Glomset提出的DG激酶亚型是一种膜结合的并选择性磷酸化花生四烯酸-DG，表明这在PI周转中具有特异性。II型PA磷酸酶是膜结合的，其N-末端序列在Hic 53的部分cDNA中是保守的，Hic 53是一个H O -诱导基因。少

项目成果

近藤尚武・阪上洋行他1名: "Enhanced gene expression for phosphatidylinositol 3-kinase in the hypoglossal motonewons following axonal crush." Mol Brain Res.37. 329-332 (1996)

Naotake Kondo、Hiroyuki Sakagami 和其他 1 人：“轴突挤压后舌下运动神经元中磷脂酰肌醇 3-激酶的基因表达增强。” Mol Brain Res.329-332 (1996)。

J.P.Walsh, R.Suen & J.A.Glomset: "Arachidonoyl-diacylglycerol kinase, specific in vitro inhibition by phosphoinositides suggests a mechanism for regulation of phosphatidylinositol biosynthesis." J.Biol.Chem.270. 28647-28653 (1995)

J.P.沃尔什，R.孙

中川有,後藤薫と近藤尚武: "Cloning and characterization of sluble phosphatidylinositol 4-kinase of 92 kDa" Biochem.J.320. 643-649 (1996)

Yu Nakakawa、Kaoru Goto 和 Naotake Kondo：“92 kDa 的可溶解磷脂酰肌醇 4-激酶的克隆和表征”Biochem.J.320 (1996)。

Y.Ito, H.Sakagami, H.Kondo: "Enhanced gene expression for phosphatidylinositol 3-kinase in the hypoglossal motoneurons following axonal crush." Mol.Brain Res.37. 329-332 (1996)

Y.Ito、H.Sakagami、H.Kondo：“轴突挤压后舌下运动神经元中磷脂酰肌醇 3-激酶的基因表达增强。”

K.Goto & H.Kondo: "Heterogeneity of diacylglycerol kinase in terms of molecular structure, biochemical characteristics and gene expression localization in the brain." J.Lipid Med.14. 251-257 (1996)

后藤健一