Functional regulation of centrosome and Golgi apparatus by signal-anchoring proteins.

CG-NAP（centrosome and Golgi localized PKN-associated protein）是一种卷曲螺旋蛋白，被鉴定为PKN调节结构域的结合蛋白，其羧基端区域具有与PKC高度同源的催化结构域，氨基端区域具有独特的调节结构域。本研究分析了CG-NAP在高尔基体形成和中心体分裂中的作用，得到以下结果.发现CG-NAP与微管和细胞质动力蛋白亚基p150^相互作用<Glued>，并以微管依赖性方式定位于高尔基体。通过检测解聚微管或抑制细胞质动力蛋白的恢复过程，发现CG-NAP通过与细胞质动力蛋白相互作用被募集到微管的负端，从而定位于高尔基体.哺乳动物细胞中的高尔基体形成一个连续的带状结构，由相互连接的扁平池堆叠而成， ...更多信息 d靠近中心体。无论是分子的要求，也没有目的，高尔基带的形成是已知的。结果表明，在高尔基体缺乏CG-NAP的细胞中，高尔基体是破碎的。在这些细胞中，膜蛋白的转运和糖基化正常发生，但有一些延迟，表明这些堆叠是功能性的。这些结果表明，CG-NAP是高尔基体侧融合形成功能完整的细胞器所必需的.在G2期晚期，中心体分裂发生在重复的中心体之间，这是由蛋白激酶Nek 2A磷酸化两个中心体之间的凝聚蛋白引起的。当CG-NAP或Kendrin被siRNA抑制时，分裂中心体的细胞比例增加。此外，发现这些蛋白质与超磷酸化的失活Nek 2A特异性相关，表明它们在抑制中心体Nek 2A活性中的作用。Nek 2A抑制的可能机制，如磷酸化和结合，正在研究中。少

CG-NAP (centrosome and Golgi localized PKN-associated protein) is a coiled-coil protein identified as a binding protein for the regulatory domain of PKN that has a catalytic domain highly homologous to PKC in the carboxyl-terminal region and a unique regulatory domain in the amino-terminal region. In this study, we have analyzed the function of CG-NAP in the Golgi formation and centrosome splitting and obtained the results as follows.1. CG-NAP was found to interact with both microtubules and a cytoplasmic dynein subunit p150^<Glued> and localize to the Golgi apparatus in a microtubule-dependent manner. By examining the recovery process from the depolymerizing microtubules or inhibiting cytoplasmic dynein, it was revealed that CG-NAP is recruited to the minus ends of microtubules by interacting with cytoplasmic dynein, thereby localizes to the Golgi apparatus.2. The Golgi apparatus in mammalian cells forms a continuous ribbon of interconnected stacks of flat cisternae that are positione … More d close to the centrosome. Neither the molecular requirements for, nor the purpose of, Golgi ribbon formation are known. It was revealed that the Golgi apparatus is fragmented in the cells lacking CG-NAP at the Golgi. In these cells transport and glycosylation of membrane proteins occurred normally with some delay, indicating that these stacks are functional. These results suggest that CG-NAP is required for the lateral fusion of the Golgi stacks to form fully functional apparatus.3. The centrosome splitting occurs between duplicated centrosomes at late G2 phase, which is caused by phosphorylation of cohesion proteins between two centrosomes by a protein kinase Nek2A. The ratio of the cells with split centrosomes was increased when CG-NAP or kendrin was suppressed by siRNA. Further, these proteins were found to associate specifically with hyper-phosphorylated inactive Nek2A, suggesting their role in the suppression of Nek2A activity at centrosomes. Possible mechanisms of Nek2A inhibition, such as phosphorylation and binding, are being examined. Less