A Steroid-Conjugated Contrast Agent for Magnetic Resonance Imaging of Cell Signaling

摘要

One of the most challenging areas of research in cell biology is tracking cell signaling pathways to understand mechanisms.In an effort to elucidate cell signaling mechanisms,transcriptional systems that can be activated by exogenous molecules have been developed.The GAL4-UAS transcriptional system has a truncated form of the progesterone receptor(PR)hormone-binding domain fused to a gene transactivation domain.The mutated receptor fails to bind progesterone yet retains the ability to bind the synthetic progesterone antagonist RU-486(mifepristone,Scheme 1).The binding of the mutated progesterone receptor to RU-486 triggers a signal trans-duction cascade by activating transcription of lac-Z,the target reporter gene.This gene switch system is particularly useful for tracking the cell signaling in vitro and in vivo with an appropriate imaging strategy.