Proteomic and Phosphoproteomic Profiling of Heart in Pak2cko Mice Under Pressure Overload

This study employs a factorial design to delineate the combinatorial effects of cardiac-specific conditional gene knockout and pressure overload-induced cardiac hypertrophy via transverse aortic constriction (TAC). Four experimental cohorts were established: (1) conditional knockout mice subjected to TAC (CKO_TAC), (2) knockout controls with Sham surgery (CKO_Sham), (3) floxed control mice receiving TAC (ff_TAC), and (4) floxed Sham-operated controls (ff_Sham). Following a 5-week pressure overload (TAC), myocardial tissue underwent parallel proteomic and phosphoproteomic profiling using TMT-based quantitative mass spectrometry. This dual-omics approach specifically interrogates: (a) the intrinsic genetic perturbation effect (CKO_ Sham vs ff_ Sham), (b) the pure pressure overload response (ff_TAC vs ff_Sham), and critically, (c) the genotype-by-environment interaction through synergistic/antagonistic divergence between observed versus predicted additive effects in CKO_TAC relative to genetic and surgical controls. Phosphoproteomic data further resolve signaling pathway dynamics underlying phenotypic modulation.