Atypical tyrosine-protein kinase that plays a central role in chromatin remodeling and acts as a transcription regulator . Involved in DNA damage response by phosphorylating 'Tyr-142' of histone H2AX (H2AXY142ph) (, ). H2AXY142ph plays a central role in DNA repair and acts as a mark that distinguishes between apoptotic and repair responses to genotoxic stress (, ). Regulatory subunit of the ATP-dependent WICH-1 and WICH-5 ISWI chromatin remodeling complexes, which form ordered nucleosome arrays on chromatin and facilitate access to DNA during DNA-templated processes such as DNA replication, transcription, and repair (, ). Both complexes regulate the spacing of nucleosomes along the chromatin and have the ability to slide mononucleosomes to the center of a DNA template . The WICH-1 ISWI chromatin remodeling complex has a lower ATP hydrolysis rate than the WICH-5 ISWI chromatin remodeling complex . The WICH-5 ISWI chromatin-remodeling complex regulates the transcription of various genes, has a role in RNA polymerase I transcription (By similarity). Within the B-WICH complex has a role in RNA polymerase III transcription . Mediates the recruitment of the WICH-5 ISWI chromatin remodeling complex to replication foci during DNA replication .
Subcellular locations: Nucleus
Accumulates in pericentromeric heterochromatin during replication . Co-localizes with PCNA at replication foci during S phase . Co-localizes with SMARCA5/SNF2H at replication foci during late-S phase . Also localizes to replication foci independently of SMARCA5/SNF2H and PCNA . Localizes to sites of DNA damage .
Ubiquitously expressed with high levels of expression in heart, brain, placenta, skeletal muscle and ovary.