RAB GERANYLGERANYL TRANSFERASE CATALYZES THE GERANYLGERANYLATION OF ADJACENT CYSTEINES IN THE SMALL GTPASES RAB1A, RAB3A, AND RAB5A
RAB GERANYLGERANYL TRANSFERASE CATALYZES THE GERANYLGERANYLATION OF ADJACENT CYSTEINES IN THE SMALL GTPASES RAB1A, RAB3A, AND RAB5A
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DOI：
10.1073/pnas.91.25.11963
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发表时间：
1994-12-06
影响因子：
11.1
通讯作者：
GLOMSET, JA
中科院分区：
文献类型：
--
作者：
FARNSWORTH, CC;SEABRA, MC;GLOMSET, JA
Rab 蛋白是 Ras 相关的小 GTP 酶，在位于或靠近其 C 末端的半胱氨酸残基上进行香叶基香叶基化，它们在几个重要方面与其他香叶基香叶基化的小 GTP 酶不同。 (i) 大多数 Rab 蛋白在下列 C 末端序列之一内含有两个相邻的半胱氨酸残基：-XXCC、-XCXC 或 -CCXX； (ii) 以 -XCXC 蛾结尾的 Rab 蛋白已被证明在两个相邻的半胱氨酸残基上都被香叶基香叶基化； (iii) Rab 蛋白是独特的 Rab 特异性香叶基香叶基转移酶的底物。该酶是否催化两个半胱氨酸的香叶基香叶基化尚不清楚。我们通过体外异戊二烯化蛋白的直接结构分析解决了这个问题，我们将重组 Rab 香叶基香叶基转移酶、Rab 护送蛋白和 [1-H-3]香叶基香叶基焦磷酸与重组野生型 Rab1A (-XXCC)、Rab3A (-XCXC) 或 Rab5A (-CCXX) 一起孵育，并用胰蛋白酶处理每个标记的蛋白质，然后通过 HPLC 和电喷雾质量分析所得肽光谱分析，发现每个蛋白质的两个 C 端相邻半胱氨酸都被香叶基香叶基化，这些结果表明 Rab 香叶基香叶基转移酶/Rab 护送蛋白催化具有三个不同 C 端蛾的 Rab 蛋白中两个半胱氨酸的香叶基香叶基化，并表明具有这些基序的其他 Rab 蛋白可能被类似地修饰。
Rab proteins are Ras-related small GTPases that are geranylgeranylated on cysteine residues located at or near their C termini, They differ from other geranylgeranylated small GTPases in several important respects. (i) Most Rab proteins contain two adjacent cysteine residues within one of the following C-terminal sequence moths: -XXCC, -XCXC, or -CCXX; (ii) a Rab protein that ends in a -XCXC moth has been shown to be geranylgeranylated on both adjacent cysteine residues; and (iii) Rab proteins are substrates of a unique Rab-specific geranylgeranyltransferase. Whether this enzyme catalyzes the geranylgeranylation of both cysteines is unknown. We addressed this question by direct structural analysis of in vitro prenylated proteins, We incubated recombinant Rab geranylgeranyltransferase, Rab escort protein, and [1-H-3]geranylgeranyl pyrophosphate with recombinant wild-type Rab1A (-XXCC), Rab3A (-XCXC), or Rab5A (-CCXX) and treated each labeled protein with trypsin, We then analyzed the resulting peptides by HPLC and electrospray mass spectrometry and found that for each protein both C-terminal adjacent cysteines were geranylgeranylated, These results indicate that Rab geranylgeranyltransferase/Rab escort protein catalyzes the geranylgeranylation of both cysteines in Rab proteins with three distinct C-terminal moths and suggest that other Rab proteins with these motifs may be similarly modified.