Morgado-Díaz J A, Montesano G, De Souza Fernandes S, Redondo P A, Fernandes de Souza W, Albuquerque-Xavier A C, Leve F, Tanaka M N, Martins de Araujo W, Oliveira S S, Benchimol Marlene, De Souza W
Grupo de Biologia Estrutural, Divisão de Biologia Celular, Centro de Pesquisas, Instituto Nacional de Câncer, Rio de Janeiro, RJ 20231-050, Brazil.
Tissue Cell. 2007 Jun;39(3):161-9. doi: 10.1016/j.tice.2007.03.001. Epub 2007 Apr 6.
We examined the participation of MAPK and PKA in the Golgi complex disassembly caused by light-activated Calphostin C in HT-29 cells. When these cells were incubated with Calphostin C, fragmentation and dispersal of the Golgi complex was observed as assessed by immunofluorescence microscopy. Electron microscopy analysis showed that clusters of vesicles and large tubule-vesicular membrane structures, resembling the Golgi remnants present in mitotic cells, substituted the Golgi stacks. In addition, Calphostin C treatment caused inhibition of the endocytic route. We confirmed that the Golgi disassembly was not due to PKC inhibition, and suggested, based on the use of specific inhibitors, that other kinases are involved. It was shown that pretreatment with PD98059 and H-89, both inhibitors of MAPK and PKA, respectively, prior to incubation with Calphostin C, caused blockade of the Golgi disassembly, as well as the inhibition of the endocytic pathway caused by this drug. This finding supports the existence of a novel mechanism by which MAPK and PKA may regulate the Golgi breakdown caused by Calphostin C in HT-29 cells.
我们研究了丝裂原活化蛋白激酶（MAPK）和蛋白激酶A（PKA）在光激活的钙泊三醇C（Calphostin C）引起的HT-29细胞高尔基体复合体解体过程中的作用。当这些细胞与钙泊三醇C一起孵育时，通过免疫荧光显微镜评估，可观察到高尔基体复合体的碎片化和分散。电子显微镜分析表明，囊泡簇和大的管状囊泡膜结构取代了高尔基体堆栈，这些结构类似于有丝分裂细胞中存在的高尔基体残余物。此外，钙泊三醇C处理导致内吞途径受到抑制。我们证实高尔基体解体并非由于蛋白激酶C（PKC）抑制所致，并基于使用特异性抑制剂表明，其他激酶也参与其中。结果显示，在与钙泊三醇C孵育之前，分别用MAPK抑制剂PD98059和PKA抑制剂H-89进行预处理，可导致高尔基体解体被阻断，以及该药物引起的内吞途径抑制。这一发现支持了一种新机制的存在，即MAPK和PKA可能通过该机制调节钙泊三醇C在HT-29细胞中引起的高尔基体解体。
