PHD finger found in protein Jade-1 and similar proteins
Jade-1, also termed PHD finger protein 17 (PHF17), is a novel binding partner of von Hippel-Lindau (VHL) tumor suppressor Pvhl, a key regulator of the cellular oxygen sensing pathway. It is highly expressed in renal proximal tubules. Jade-1 functions as an essential regulator of multiple cell signaling pathways. It may be involved in the serine/threonine kinase AKT/AKT1 pathway during renal cancer pathogenesis and normally prevents renal epithelial cell proliferation and transformation. It also acts as a pro-apoptotic and growth suppressive ubiquitin ligase to inhibit canonical Wnt downstream effector beta-catenin for proteasomal degradation, and as a transcription factor associated with histone acetyltransferase activity and with increased abundance of cyclin-dependent kinase inhibitor p21. Moreover, Jade-1 is required for ING4 and ING5 to associate with histone acetyltransferase (HAT) HBO1 and Eaf6 to form a HBO1 complex, and plays a role in epithelial cell regeneration. It has also been identified as a novel component of the nephrocystin protein (NPHP) complex and interacts with the ciliary protein nephrocystin-4 (NPHP4). Jade-1 contains a canonical Cys4HisCys3 plant homeodomain (PHD) finger followed by a non-canonical extended PHD (ePHD) finger, Cys2HisCys5HisCys2His, both of which are zinc-binding motifs. This model corresponds to the canonical Cys4HisCys3 PHD finger.