Analysis of KRAP expression and localization, and genes regulated by KRAP in a human colon cancer cell line
Analysis of KRAP expression and localization, and genes regulated by KRAP in a human colon cancer cell line
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DOI：
10.1007/s10038-007-0204-8
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发表时间：
2007-12-01
影响因子：
3.5
通讯作者：
Shirasawa, Senji
中科院分区：
文献类型：
--
作者：
Fujimoto, Takahiro;Koyanagi, Midori;Shirasawa, Senji
我们先前从人结肠癌HCT 116细胞的cDNA文库中鉴定了人KRAP（Ki-ras诱导的肌动蛋白相互作用蛋白）基因，其表达水平被激活的Ki-ras上调。虽然KRAP基因在结构上从鱼类到哺乳动物物种都是保守的，但KRAP的表达模式和功能仍有待阐明。在这里，我们已经产生了KRAP的特异性多克隆抗体，并表征了KRAP在小鼠组织中的组织学表达。KRAP在小鼠组织中广泛表达，在胰腺、肝脏和棕色脂肪组织中表达水平较高，并且KRAP与丝状肌动蛋白沿着胰腺和肝脏组织的顶膜共定位。亚分级研究表明，KRAP是一种细胞质蛋白，大多数与细胞骨架有关。此外，通过抑制HCT 116细胞中KRAP表达的微阵列基因表达谱显示，在癌症中经常失调的几种受体和信号分子在KRAP敲低的细胞中差异表达。这些结果提示KRAP可能是一种细胞凋亡相关蛋白，参与了肿瘤的结构完整性和/或信号转导。
We previously identified the human KRAP (Ki-ras-induced actin-interacting protein) gene from the cDNA library of human colon cancer HCT116 cells as one of the genes whose expression levels were up-regulated by activated Ki-ras. Although the KRAP gene is structurally conserved from fish to mammalian species, the expression pattern and function of KRAP still remain to be elucidated. Here, we have generated a specific polyclonal antibody for KRAP and characterized the histological expression of KRAP in mouse tissues. KRAP was ubiquitously expressed in mouse tissues, with high levels in pancreas, liver, and brown adipose tissues, and KRAP was co-localized with filamentous actin along the apical membranes in both pancreas and liver tissues. A subfractionation study revealed that KRAP is a cytoplasmic protein and that the majority is associated with the cytoskeleton. Furthermore, microarray gene expression profile by inhibiting KRAP expression in HCT116 cells showed that several receptors and signal molecules frequently deregulated in cancers were differentially expressed in the KRAP-knockdown cells. All of these results suggested that KRAP might be a cytoskeleton-associated protein involving the structural integrity and/or signal transductions in human cancers.