THE C1 DOMAIN IN CANCER SIGNALING MOLECULES: REGULATION BY LIPIDS AND PROTEIN-PROTEIN INTERACTIONS

摘要: Cysteine-rich (C1) domains, present in PKC isozymes, Chimaerins, RasGRPs, PKDs, Munc13s, DGKs, and MRCKs, can bind the diacylglycerol (DAG) second messenger. In thesis research, I demonstrated that p23/Tmp21 acts as a C1-domain docking protein mediates perinuclear translocation of beta2-chimaerin. Glu227 Leu248 beta2-chimaerin are crucial for binding targeting. Isolated C1-domains from individual isozymes or RasGRP1 differentially interact with p23/Tmp21. PKCepsilon interacts specifically via its C1b domain, however this association is lost response to phorbol esters. These results demonstrate an anchor distinctively modulates compartmentalization C1-domain-containing proteins, it plays essential role re-localization region It has been established apoptosis induced by esters LNCaP cells primarily mediated novel PKCdelta. depletion significantly potentiates 12-myristate 13-acetate (PMA)-induced cells. Remarkably, effect was PKCdelta revealed fact RNAi inhibitor GF 109203X rescue potentiating depletion. Immunoprecipitation confocal microscopy analysis formed complex Disruption PKCdelta-p23/Tmp21 accelerates PMA-induced plasma membrane activation downstream effector ROCK JNK. Moreover, doxorubicin-mediated This work provided first evidence negatively regulates PKCdelta-mediated PMA doxorubicin. addition, radiosensitizes PC3 androgen-independent prostate cancer Depletion but not PKCalpha shRNA, Confocal images gammairradiation-induced impaired EGFR AG1478, PLCgamma1 U73122, ROS scavenger N-acetyl-cysteine (NAC). The potential DAG containing control ionizing irradiation cell death/survival also suggested inhibition may be useful therapeutic approach radiosensitize Taken together, several findings highlight relevance proteins cancer. Degree Type Dissertation Name Doctor Philosophy (PhD) Graduate Group Pharmacological Sciences dissertation available at ScholarlyCommons: http://repository.upenn.edu/edissertations/141 First Advisor Marcelo G. Kazanietz