Involved in many cell functions, including pre-mRNA splicing, the aryl hydrocarbon receptor (AHR pathway, F-actin organization and protein ubiquitination. Plays a role in the dynamic organization of the actin skeleton as a stabilizer of actin filaments by association with F-actin through Kelch repeats (By similarity. Protects cells from cell death induced by actin destabilization (By similarity. Functions as modifier of the AHR/Aryl hydrocarbon receptor pathway increasing the concentration of AHR available to activate transcription. In addition, functions as a negative regulator of BCR(KLHL20 E3 ubiquitin ligase complex to prevent ubiquitin-mediated proteolysis of PML and DAPK1, two tumor suppressors. Inhibits pre-mRNA splicing (in vitro.