PSF controls expression of histone variants and cellular viability in thymocytes

► The multifunctional RNA processing factor PSF is essential for cell viability. ► T cell-specific knock down of PSF causes loss of thymic cellularity via apoptosis. ► PSF-depleted thymocytes have a specific reduction in a subset of histone mRNAs. ► Reduced expression of histone cluster 1 H2AE specifically induces apoptosis.