Slager Rebecca E, Devasure Jane M, Pavlik Jaqueline A, Sisson Joseph H, Wyatt Todd A
Department of Internal Medicine, Pulmonary and Critical Care Medicine Section, University of Nebraska Medical Center, 985300 Nebraska Medical Center, Omaha, NE 68198-5300, USA.
J Histochem Cytochem. 2008 Jan;56(1):7-14. doi: 10.1369/jhc.7A7249.2007. Epub 2007 Sep 17.
The novel isoform of protein kinase C (PKC), PKCepsilon, is an important regulator of ciliated cell function in airway epithelial cells, including cilia motility and detachment of ciliated cells after environmental insult. However, the mechanism of PKCepsilon signaling in the airways and the potential role of the PKCepsilon-interacting protein, receptor for activated C kinase 1 (RACK1), has not been widely explored. We used immunohistochemistry and Western blot analysis to show that RACK1 is localized exclusively to basal, non-ciliated (and non-goblet) bovine and human bronchial epithelial cells. Our immunohistochemistry experiments used the basal body marker pericentrin, a marker for cilia, beta-tubulin, and an airway goblet cell marker, MUC5AC, to confirm that RACK1 was excluded from differentiated airway cell subtypes and is only expressed in the basal cells. These results suggest that PKCepsilon signaling in the basal airway cell may involve RACK1; however, PKCepsilon regulation in ciliated cells uses RACK1-independent pathways.
蛋白激酶C（PKC）的新型同工型PKCε，是气道上皮细胞中纤毛细胞功能的重要调节因子，包括纤毛运动以及环境损伤后纤毛细胞的脱离。然而，PKCε在气道中的信号传导机制以及PKCε相互作用蛋白——活化C激酶1受体（RACK1）的潜在作用，尚未得到广泛研究。我们使用免疫组织化学和蛋白质印迹分析表明，RACK1仅定位于牛和人支气管上皮的基底、无纤毛（且无杯状）细胞。我们的免疫组织化学实验使用了基体标记物中心粒蛋白、纤毛标记物β-微管蛋白以及气道杯状细胞标记物MUC5AC，以确认RACK1不存在于分化的气道细胞亚型中，仅在基底细胞中表达。这些结果表明，气道基底细胞中的PKCε信号传导可能涉及RACK1；然而，纤毛细胞中的PKCε调节使用不依赖RACK1的途径。
