Yoshida Y, Kawata M, Katayama M, Horiuchi H, Kita Y, Takai Y
Department of Biochemistry, Kobe University School of Medicine, Japan.
Biochem Biophys Res Commun. 1991 Mar 15;175(2):720-8. doi: 10.1016/0006-291x(91)91625-m.
We have clarified that rhoA p21 purified from bovine aortic smooth muscle is geranylgeranylated at the cysteine residue in the C-terminal CAAX motif (A is an aliphatic amino acid and X is any amino acid). In this paper, a geranylgeranyltransferase for rhoA p21 (rhoA p21 GGT) was partially purified from bovine brain cytosol. This enzyme transferred a geranylgeranyl moiety from geranylgeranyl pyrophosphate to rhoA p21 having the CAAX motif (rhoA p21-CAAX) but not to rhoA p21 lacking the AAX portion. rhoA p21 GGT was separated from the previously reported farnesyltransferase for ras p21s (ras p21 FT) by column chromatographies and did not geranylgeranylate or farnesylate c-Ha-ras p21-CAAX. ras p21 FT did not geranylgeranylate or farnesylate rhoA p21-CAAX. These results indicate that rhoA p21 GGT distinct from ras p21 FT is present in bovine brain cytosol.
我们已经阐明，从牛主动脉平滑肌中纯化的rhoA p21在其C末端CAAX基序（A为脂肪族氨基酸，X为任意氨基酸）的半胱氨酸残基处发生了香叶基香叶基化。在本文中，一种用于rhoA p21的香叶基香叶基转移酶（rhoA p21 GGT）从牛脑细胞质中得到了部分纯化。该酶将香叶基香叶基部分从香叶基香叶基焦磷酸转移至具有CAAX基序的rhoA p21（rhoA p21-CAAX），但不会转移至缺少AAX部分的rhoA p21。通过柱色谱法将rhoA p21 GGT与先前报道的用于ras p21的法尼基转移酶（ras p21 FT）分离，且rhoA p21 GGT不会对c-Ha-ras p21-CAAX进行香叶基香叶基化或法尼基化。ras p21 FT也不会对rhoA p21-CAAX进行香叶基香叶基化或法尼基化。这些结果表明，与ras p21 FT不同的rhoA p21 GGT存在于牛脑细胞质中。
