|Activator protein-2α functions as a master regulator of multiple transcription factors in the mouse liver.
|Year of Publication
|Li Q, Luo C, Löhr CV, Dashwood RH
AIM: Activator protein 2α (AP-2α) belongs to the AP-2 family of transcription factors that are involved in the regulation of cell proliferation, differentiation, apoptosis and carcinogenesis and has been suggested to function as a tumor suppressor in many cancers. However, the physiological role of AP-2α in hepatocytes is unknown. The present study is to characterize the expression and function of AP-2α in the liver of conscience mouse.
METHODS: Exogenous AP-2α was overexpressed in the mouse liver by in vivo gene delivery and changes in transcription factor expression were identified by using protein-DNA arrays and immunoblotting.
RESULTS: Western blotting and protein/DNA arrays showed that AP-2α is expressed in the nuclei of mouse hepatocytes. Overexpression of AP-2αin vivo significantly suppressed transcription factors AP-1, CREB and c-Myc, and markedly increased CBF, c-Myb, NF-1, Pax-5, RXR, Smad3/4, TR(DR-4), USF-1 and GATA. Among all GATA proteins, only GATA-4 level was dramatically elevated and there was a concomitant loss of phospho-GATA-4. Corresponding changes were detected in upstream kinases Akt, GSK-3β and PKA, which regulates the phosphorylation status and stability of GATA-4 protein.
CONCLUSIONS: AP-2α is expressed in mouse hepatocytes and it acts as a master regulator of numerous transcription factors in the liver.
|PubMed Central ID
|P01 CA090890 / CA / NCI NIH HHS / United States
R01 CA080176 / CA / NCI NIH HHS / United States
R01 CA122959 / CA / NCI NIH HHS / United States