TISSUE-SPECIFIC VARIATIONS IN THE EXPRESSION AND REGULATION OF THE SMALL GTP-BINDING PROTEIN-RHO
TISSUE-SPECIFIC VARIATIONS IN THE EXPRESSION AND REGULATION OF THE SMALL GTP-BINDING PROTEIN-RHO
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DOI：
10.1016/0167-4889(94)90038-8
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发表时间：
1994-07-21
影响因子：
5.1
通讯作者：
JUST, I
中科院分区：
文献类型：
--
作者：
FRITZ, G;LANG, P;JUST, I
Rho蛋白参与调节微血管细胞网络的组装，并且已知是来自肉毒梭菌的ADP-核糖基转移酶C3的特异性底物。在这里，我们研究了分布的Rho和Rho调节蛋白的提取物从各种兔组织。在肺和肾的细胞提取物中检测到最高量的[P-32] ADP-核糖基化蛋白。与这些组织相比，在来自肝、脾、脑、心脏和肌肉的提取物中观察到Rho蛋白的标记减少50-95%。Rho的C3介导的[P-32] ADP-核糖基化水平与通过Western分析检测到的RhoA蛋白的量不相关。[P-32] ADP-核糖基化蛋白位于胞质或膜组分的相对量，分别取决于研究的组织类型，表明Rho蛋白亚细胞分布的组织特异性变化。Rho与其他因子的复合以及不同Rho物种的表达也是如此。在Rho调节蛋白中，肺和脑的提取物含有最高量的鸟嘌呤核苷酸解离抑制蛋白（Rho-GDI）。然而，Rho与Rho-GDI的关联显示出组织特异性，并且与Rho-GDI量不相关。Rho-GAP（GAP = GTP酶激活蛋白）活性在肺、肾和脾的提取物中最高，在肌肉和心脏的提取物中最低。总之，我们的数据表明RhoA，[P-32] ADP-核糖基化蛋白和Rho调节因子的表达存在组织特异性差异，表明Rho蛋白的活性和调节存在组织特异性变化。
Rho proteins are involved in the regulation of the assembly of the microfilamental cellular network and are known to be specific substrates for the ADP-ribosyltransferase C3 from Clostridium botulinum. Here, we studied the distribution of Rho and Rho-regulating proteins in extracts from various rabbit tissues. The highest amounts of [P-32]ADP-ribosylated proteins were detected in cell extracts from lung and kidney. Compared to these tissues, 50-95% reduced labeling of Rho proteins was observed in extracts from liver, spleen, brain, heart and muscle. The level of the C3-mediated [P-32]ADP-ribosylation of Rho did not correlate with the amount of RhoA proteins detected by Western analysis. The relative amounts of [P-32]ADP-ribosylated proteins located in cytosolic or membrane fractions, respectively, depended on the type of tissue investigated, indicating a tissue-specific variation in the subcellular distribution of Rho proteins. The same was true for the complexation of Rho with other factors and the expression of diverse Rho species. In respect to Rho-reguiating proteins, extracts from lung and brain contained the highest amounts of guanine nucleotide dissociation-inhibitor proteins (Rho-GDI). The association of Rho with Rho-GDI however showed tissue specificity and did not correlate with Rho-GDI amounts. The highest Rho-GAP (GAP = GTPase-activating protein) activities were observed in extracts from lung, kidney and spleen, the lowest ones in extracts from muscle and heart. In total, our data demonstrate tissue-specific differences in the expression of RhoA, [P-32]ADP-ribosylated proteins and Rho-regulating factors, indicating a tissue-specific variation in the activity and regulation of Rho proteins.