Scaffold subunit of some HBO1 complexes, which have a histone H4 acetyltransferase activity. Plays a key role in HBO1 complex by directing KAT7/HBO1 specificity towards histone H4 acetylation (H4K5ac, H4K8ac and H4K12ac), regulating DNA replication initiation, regulating DNA replication initiation. May also promote acetylation of nucleosomal histone H4 by KAT5. Promotes apoptosis. May act as a renal tumor suppressor. Negatively regulates canonical Wnt signaling; at least in part, cooperates with NPHP4 in this function. Component of the HBO1 complex composed at least of ING4 or ING5, KAT7/HBO1, MEAF6, and one of JADE1, JADE2 and JADE3. Interacts with NPHP4. Localizes to the ciliary transition zone. The 2 PHD-type zinc fingers are required for transcriptional activity. Belongs to the JADE family.