The role of activin binding protein in the activin signal transduction.

激活素结合蛋白在激活素信号转导中的作用。

• 批准号: 04454597
• 负责人: SUGINO Hiromu
• 金额: $ 4.22万
• 依托单位: The University of Tokushima
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (B)
• 财政年份: 1992
• 资助国家: 日本
• 起止时间: 1992 至 1993
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-04454597/
• 关键词: activin; follistatin; dual kinase; heparan sulfate; ヘパラン硫酸; 結合タンパク質; リン酸化; シグナル伝達

Activins are members of a large family of transforming growth factors beta, and has various functions, including stimulation of hematopoiesis, paracrine regulation of ovarian and testicular function, modulation of nerve cell differentiation and induction of mesodermal tissues in Xenopus embryo. To understand the expression mechanism for diverse actions of activin, we investigated the molecular mechanism of activin signal transduction and obtained the following findings.(1) We have recently isolated the activin receptor from the mouse embryonal carcinoma (EC) cell line P19, and found that the activin receptor is a transmembrane serine/threonine/tyrosine protein kinase. In this study, we isolated a mouse activin receptor (type II) protein from COS cells transiently expressed the activin receptor (type II) DNA by the same affinity chromatography as from ECP19 cells. The purified receptor protein was also found to phosphorylate both itself and substrate proteins on serine, threonine and ty … More rosine residues. To date, no transmembrane-type kinase with dual kinase activity has been reported. Accordingly, we may propose that signal transduction of activin employs a novel pathway via a new class of cellular receptor.(2) We examined the stoichiometric interaction between activin and follistatin (activin-binding protein) by FPLC gel filtration, and found that the molar ratio of follistatin to activin was 2 : 1. This ratio was also confirmed by testing the stimulating or inhibiting effect of the activin-follistatin mixtures on FSH-release by cultured pituitary cells. These results indicate that two moles of follistatin is necessary for complete inhibition of the activity of one mole activin. Furthermore, we purified six molecular forms of follistatin from porcine ovaries. Protein chemical analysis revealed that the structural differences among the six forms were caused by truncation of the C-terminal region and/or the presence of carbohydrate chains. All six molecular species were found to have the same activin binding activity, By contrast, the C-terminal truncated form showed much higher affinity for tha rat granulosa cell surface than the C-terminal extended forms. These results suggest that cell-associated follstatin plays an important role in controlling the various actions of activin in a paracrine or autocrine manner. Less

激活素是转化生长因子β大家族的成员，具有多种功能，包括刺激造血、旁分泌调节卵巢和睾丸功能、调节神经细胞分化以及诱导非洲爪蟾胚胎中的中胚层组织。为了了解激活素多种作用的表达机制，我们研究了激活素信号转导的分子机制，并获得了以下发现。（1）我们最近从小鼠胚胎癌（EC）细胞系P19中分离到激活素受体，发现激活素受体是一种跨膜丝氨酸/苏氨酸/酪氨酸蛋白激酶。在本研究中，我们通过与 ECP19 细胞相同的亲和层析，从瞬时表达激活素受体（II 型）DNA 的 COS 细胞中分离出小鼠激活素受体（II 型）蛋白。还发现纯化的受体蛋白能够磷酸化其自身以及丝氨酸、苏氨酸和松氨酸残基上的底物蛋白。迄今为止，尚未报道具有双重激酶活性的跨膜型激酶。因此，我们可以提出，激活素的信号转导采用了一种新的细胞受体途径。(2)我们通过FPLC凝胶过滤检查了激活素和卵泡抑素(激活素结合蛋白)之间的化学计量相互作用，发现卵泡抑素与激活素的摩尔比为2:1。通过测试卵泡抑素的刺激或抑制作用也证实了这一比例。 激活素-卵泡抑素混合物对培养的垂体细胞释放 FSH 的影响。这些结果表明，两摩尔卵泡抑素对于完全抑制一摩尔激活素的活性是必需的。此外，我们从猪卵巢中纯化了六种分子形式的卵泡抑素。蛋白质化学分析表明，六种形式之间的结构差异是由 C 末端区域的截短和/或碳水化合物链的存在引起的。发现所有六种分子种类都具有相同的激活素结合活性。相比之下，C端截短形式对大鼠颗粒细胞表面的亲和力比C端延伸形式高得多。这些结果表明细胞相关的卵泡抑素在以旁分泌或自分泌方式控制激活素的各种作用中发挥重要作用。较少的

项目成果

T.Nakamura et al.: "Follistatin inhibits activin-induced differentiation of rat follicular granulosa calls in vitro." Biochem.Biophys.Acta. 1135. 103-109 (1992)

T.Nakamura 等人：“卵泡抑素在体外抑制激活素诱导的大鼠滤泡颗粒细胞分化。”

T.Nakamura et al.: "Follistatin inhibits activin-induced differentiation of rat follicular granulosa calls in vitro." Biochem. Biophys. Acta. 1135. 103-109 (1992)

T.Nakamura 等人：“卵泡抑素在体外抑制激活素诱导的大鼠滤泡颗粒细胞分化。”

K.Ogawa et al.: "Exoression of alpha, betaA and betaB subunits of inhibin or activin and follistatin in rat pancreatic islets." FEBS Lett.319. 217-220 (1993)

K.Okawa 等人：“大鼠胰岛中抑制素或激活素和卵泡抑素的 α、βA 和 βB 亚基的外排”。

R.Demura et al.: "Competitive protein binding assay for activin A/EDF using follistatin : Determination of activin levels in human plasma." Biochem. Biophys. Res. Commum.185. 1148-1154 (1992)

R.Demura 等人：“使用卵泡抑素对激活素 A/EDF 进行竞争性蛋白结合测定：测定人血浆中的激活素水平。”

T.Nakamura et al.: "Isolation and characterization of native activin B." J.Biol. Chem.267. 16385-16389 (1992)

T.Nakamura 等人：“天然激活素 B 的分离和表征。”