Rab geranylgeranyl transferase. A multisubunit enzyme that prenylates GTP-binding proteins terminating in Cys-X-Cys or Cys-Cys.
Rab geranylgeranyl transferase. A multisubunit enzyme that prenylates GTP-binding proteins terminating in Cys-X-Cys or Cys-Cys.
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DOI：
10.1016/s0021-9258(19)49740-8
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发表时间：
1992-07
期刊：
影响因子：
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通讯作者：
Miguel C. Seabra;Joseph L. Goldstein;Thomas C. Südhof;Thomas C. Südhof;Michael S. Brown
中科院分区：
文献类型：
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作者：
Miguel C. Seabra;Joseph L. Goldstein;Thomas C. Südhof;Thomas C. Südhof;Michael S. Brown
Rab 蛋白是膜结合的异戊二烯化 GTP 结合蛋白，是膜囊泡从一个细胞器定向移动到另一个细胞器所需的。在本文中，我们表征并纯化了一种酶，该酶将香叶基香叶基残基附着到带有COOH末端序列Cys-X-Cys（例如Rab3A）和Cys-Cys（例如Rab1A）的Rab蛋白上。该酶被命名为 Rab 香叶基香叶基转移酶（Rab GG 转移酶）。在高盐浓度下，大鼠脑细胞质中的 Rab GG 转移酶分离成两种成分，分别称为 A 和 B，这两种成分都是活性所必需的。我们将组分 B 纯化至表观同质性，发现它含有 60 和 38 kDa 的两种肽。纯化的 Rab GG 转移酶不会将香叶基香叶基连接到 p21H-ras-CVLL，p21H-ras-CVLL 被类似于 CAAX 法呢基转移酶的 CAAX 型 GG 转移酶异戊二烯化。 Rab GG 转移酶被 Zn2+ 强烈抑制，Zn2+ 是法呢基转移酶绝对需要的阳离子。超过 100 mM 的 NaCl 浓度也会抑制 Rab GG 转移酶。结合之前的数据，目前的研究结果表明，哺乳动物细胞拥有至少三种蛋白质异戊烯基转移酶（CAAX 法尼基转移酶、CAAX GG 转移酶和 Rab GG 转移酶），它们对不同类别的低分子量 GTP 结合蛋白和其他蛋白质具有特异性。
Rab proteins are membrane-bound prenylated GTP-binding proteins required for the targeted movement of membrane vesicles from one organelle to another. In the current paper we have characterized and purified an enzyme that attaches geranylgeranyl residues to Rab proteins that bear the COOH-terminal sequence Cys-X-Cys (such as Rab3A) and Cys-Cys (such as Rab1A). This enzyme is designated Rab geranylgeranyl transferase (Rab GG transferase). At high salt concentrations, Rab GG transferase from rat brain cytosol separates into two components, designated A and B, both of which are required for activity. We purified Component B to apparent homogeneity and found that it contains two peptides of 60 and 38 kDa. The purified Rab GG transferase did not attach geranylgeranyl to p21H-ras-CVLL, which is prenylated by a GG transferase of the CAAX type that resembles the CAAX farnesyltransferase. Rab GG transferase was strongly inhibited by Zn2+, a cation that is absolutely required by farnesyltransferase. The Rab GG transferase was also inhibited by NaCl concentrations in excess of 100 mM. Together with previous data, the current findings indicate that mammalian cells possess at least three protein prenyltransferases (CAAX farnesyltransferase, CAAX GG transferase, and Rab GG transferase) that are specific for different classes of low molecular weight GTP-binding proteins and other proteins.