Scaffold subunit of some HBO1 complexes, which have a histone H4 acetyltransferase activity (PubMed:16387653, PubMed:19187766, PubMed:20129055, PubMed:24065767). 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 (PubMed:20129055, PubMed:24065767). May also promote acetylation of nucleosomal histone H4 by KAT5 (PubMed:15502158). Promotes apoptosis (PubMed:16046545). May act as a renal tumor suppressor (PubMed:16046545). Negatively regulates canonical Wnt signaling; at least in part, cooperates with NPHP4 in this function (PubMed:22654112). Component of the HBO1 complex composed at least of ING4 or ING5, KAT7/HBO1, MEAF6, and one of JADE1, JADE2 and JADE3 (PubMed:16387653, PubMed:19187766, PubMed:20129055, PubMed:24065767, PubMed:29382722). Interacts with NPHP4 (PubMed:22654112). Interacts with VHL and KAT5 (PubMed:12169691, PubMed:15502158). Does not associate with ING4 or ING5, and does not act as a component of the HBO1 complex (PubMed:19187766). Localizes to the ciliary transition zone. Highly expressed in kidney. Also present in pancreas, liver and heart (at protein level). Down-regulated in renal cancer cells. The 2 PHD-type zinc fingers are required for transcriptional activity. Belongs to the JADE family. Truncated N-terminus. Truncated N-terminus.