This entry includes PAX-interacting protein 1 (PTIP or Swift) and chromatin modification-related protein eaf1 (from Aspergillus fumigatus). PTIP is involved in the DNA damage response and is an adaptor protein for the ATM/ATR kinases. PTIP contains five BRCT domains with which it interacts with the activation domain of the transcription factor Pax2 []. Knockout of PTIP prevent ubiquitination of proliferating cell nuclear antigen (PCNA), and monoubiquitination of PCNA enables translesion synthesis by specialized DNA polymerases to replicate damaged DNA []. Cells without PTIP are unable to progress through mitosis []. PTIP is a component of the MLL2/MLL3 complex [], but a PTIP-PA1 subcomplex functions independently of the MLL3/MLL4 complex to mediate transcription during class switch recombination, important for generating antibody diversity []. In Saccharomyces cerevisiae, EAF1 is a component of the NuA4 histone acetyltransferase complex involved in acetylation of nucleosomal histone H4 and H2A [].
