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)代谢产生第二信使，如二酰甘油(DG)和肌醇三磷酸，以响应外界刺激。DG作为几种形式的蛋白激酶C的激活剂，被DG激酶转化为磷脂酸(PA)。另一方面，PA从磷脂酰胆碱中分离出来，并被PA磷酸酶转化为DG。PA及其代谢衍生物溶血磷脂酸是强有力的有丝分裂原和激活剂。因此，DG和PA磷酸酶在调节DG和PA的相对浓度方面起着至关重要的作用。DG和PA都是甘油脂合成的信号媒介和中间体。本研究首次从分子结构、生化特征和脑内基因表达定位的异质性方面揭示了DG激酶的异质性，并阐明了PA磷酸酶的分子同一性：H.Kondo(首席研究员)和h…鉴定了DG激酶的四种亚型(称为I-IV型)More IS组，其第五亚型(delta型)由H.Kanoh(协调员)鉴定，其第六亚型(Thita型)由W.J.van Blitterswjk(协调员)鉴定，其第七亚型(由J.A.Glomset(协调员)鉴定)，PA磷酸酶(II型)由H.Kanoh鉴定。DG激酶I型为可溶性形式，定位于少突胶质细胞中，但不存在于神经元中，在髓鞘缺陷(寒战)小鼠的脑中未见其表达，提示其在髓鞘的形成和维持中起作用。在中棘神经元、伏隔核和嗅结节的神经元以及垂体中叶的内分泌细胞中，II型DG激酶呈膜相关分布，提示其参与了多巴胺能传递。III型主要定位于浦肯野神经元，大量定位于小脑颗粒细胞，提示其在小脑运动控制中的作用。IV型定位于大脑和大脑皮层神经元，但在分子结构上具有特殊性：前三种神经元除了含有ATP结合结构域外，还含有两个EF-Hand和锌指基序，而IV型不包含EF-Hand基序，但具有Ankyrin样重复序列。该结构与果蝇视网膜变性诱导基因rdgA有很高的同源性。该基因还含有一个核靶向基序，将其导入成纤维细胞后，其蛋白定位于细胞核，提示其在转录调控中的作用。Delta型包含一个Pleckstrin同源结构域和一个DPH C末端同源结构域，而Thita类型包含三个富含半胱氨酸的结构域、一个富含Pro的区域和一个具有重叠的ras结合结构域的Pleckstrin同源结构域。J.A.Glomset的DG激酶亚型是一种膜结合的选择性磷酸酯-花生四烯酰基-DG，表明这是PI周转中特有的。II型PA磷酸酶是膜结合的，其N端序列在HO诱导基因hic53的部分cDNA中是保守的。较少

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