Investigation of PICK1 function in NIH3T3 cells by RNA interference

• Main Authors: Kuan-Jen Lin, 林冠禎
• Other Authors: Wey-Jinq Lin
• Format: Others
• Language: zh-TW
• Published: 2009
• Online Access: http://ndltd.ncl.edu.tw/handle/89684147190101829570

碩士 === 國立陽明大學 === 生物藥學研究所 === 97 === PCK1 is a PDZ-containing scaffold protein. Previous studies showed that PICK1 stabilized mitochondrial membrane potential by recruiting protein kinase C�� (PKC��) and thus reduced etoposide-induced cell death. In this study the functions of PICK1 were further investigated by using RNA interference. Mitochondria are morphologically dynamic organelles that continuously undergo fusion and fission. This process has been shown to play crucial roles in various cellular functions. I found, in this study, that down-regulation of PICK1 by shRNA in NIH3T3 cells significantly increased mitochondrial fragmentation. Furthermore, maintenance of normal mitochondrial network in parental NIH3T3 cells required PKC�� activity as treatment with a PKC��-selective inhibitor resulted in mitochondrial fragmentation. These results suggest that PICK1 may regulate mitochondrial morphology by recruiting PKC�� to mitochondria. Down-regulation of PICK1 also decreased ATP content and oxygen consumption in NIH3T3 cells suggesting a reduced oxidative phosphorylation. PICK1 knock-down cells may thus rely on anaerobic respiration for their ATP supply. This notion is supported by an increased lactate production and dependence on glucose for survival. Taken together, these observations suggest that reduced levels of PICK1 impair the mitochondrial electron transport chain and the maintenance of normal mitochondrial morphology which may be due to a destabilization of mitochondrial membrane integrity.