| Tip 60 and HDAC 7 interact with the endothelin receptor a and may be involved in downstream signaling . ^^^ Here we report that the histone acetyltransferase Tip 60 and the histone deacetylase HDAC 7 interact with one of the ET receptors , ETA , as determined by yeast two hybrid analysis , glutathione S transferase pull down assays , and co immunoprecipitation from transfected COS 7 cells . ^^^ In the absence of ET 1 , Tip 60 and HDAC 7 were localized mainly in the cell nucleus while ETA was predominantly confined to the plasma membrane . ^^^ Stimulation with ET 1 resulted in the internalization of ETA to the perinuclear compartment and simultaneously in the efflux of Tip 60 and HDAC 7 from the nucleus to the same perinuclear compartment where each protein co localized with the receptor . ^^^ Upon co transfection with ETA into COS 7 cells , Tip 60 strongly increased ET 1 induced ERK1 / 2 phosphorylation , whereas HDAC 7 had no significant effect . ^^^ |