Proteomics of rat neonatal cardiac fibroblasts

Gβγ subunits are involved in many different signalling processes in various compartments of the cell, including the nucleus. To gain insight into the functions of nuclear Gβγ, we investigated the functional role of Gβγ signalling in regulation of GPCR-mediated gene expression in primary rat neonatal cardiac fibroblasts. Following activation of the angiotensin II type I receptor in these cells, Gβγ dimers interact with RNA polymerase II (RNAPII). Our findings suggest that Gβ1γ recruitment to RNAPII negatively regulates the fibrotic transcriptional response, which can be overcome by strong fibrotic stimuli. In these specific proteomics experiments, we compared the differential protein abundance in Gβ1 knockdown and WT cardiac fibroblasts following angiotensin II treatment using a bottom-up data-dependent approach.