Multifunctional protein that is involved in the regulation of many processes including tumor suppression, apoptosis, cell cycle progression or transcription ( , ). Promotes apoptosis by favouring the activation of caspase-9/CASP9 and allowing apoptosome formation . In addition, plays a role in the modulation of histone acetylation and transcription as part of the INHAT (inhibitor of histone acetyltransferases) complex. Inhibits the histone-acetyltranferase activity of EP300/CREBBP (CREB-binding protein) and EP300/CREBBP-associated factor by histone masking . Preferentially binds to unmodified histone H3 and sterically inhibiting its acetylation and phosphorylation leading to cell growth inhibition . Participates in other biochemical processes such as regulation of mRNA nuclear-to-cytoplasmic translocation and stability by its association with ELAVL1 (Hu-antigen R) . Plays a role in E4F1-mediated transcriptional repression as well as inhibition of protein phosphatase 2A (, ).
(Microbial infection) Plays an essential role in influenza A, B and C viral genome replication ( , ). Mechanistically, mediates the assembly of the viral replicase asymmetric dimers composed of PB1, PB2 and PA via its N-terminal region . Also plays an essential role in foamy virus mRNA export from the nucleus .
Subcellular locations: Nucleus, Cytoplasm, Endoplasmic reticulum
Translocates to the cytoplasm during the process of neuritogenesis (By similarity). Shuttles between nucleus and cytoplasm.
Expressed in all tissues tested. Highly expressed in kidney and skeletal muscle, moderate levels of expression in brain, placenta and pancreas, and weakly expressed in lung. Found in all regions of the brain examined (amygdala, caudate nucleus, corpus callosum, hippocampus and thalamus), with highest levels in amygdala.