Extended PHD finger found in Jumonji domain-containing protein 2B (JMJD2B)
The extended plant homeodomain (ePHD) zinc finger is characterized as Cys2HisCys5HisCys2His. This model includes the ePHD finger of JMJD2B. JMJD2B, also termed lysine-specific demethylase 4B (KDM4B), or JmjC domain-containing histone demethylation protein 3B (JHDM3B), specifically antagonizes the trimethyl group from H3K9 in pericentric heterochromatin and reduces H3K36 methylation in mammalian cells. It plays an essential role in the growth regulation of cancer cells by modulating the G1-S transition and promotes cell-cycle progression through the regulation of cyclin-dependent kinase 6 (CDK6). It interacts with heat shock protein 90 (Hsp90) and its stability can be regulated by Hsp90. JMJD2B also functions as a direct transcriptional target of p53, which induces its expression through promoter binding. Moreover, JMJD2B expression can be controlled by hypoxia-inducible factor 1alpha (HIF1alpha) in colorectal cancer and estrogen receptor alpha (ERalpha) in breast cancer. It is also involved in bladder, lung, and gastric cancer. JMJD2B contains jmjN and jmjC domains in the N-terminal region, followed by a canonical PHD finger, this non-canonical ePHD finger, and a Tudor domain.
Conserved feature residue pattern:C C H C C C C C H C C H
Evidence:
Comment:based on the structure evidence that human Borjeson-Forssman-Lehmann syndrome-associated protein PHF6 (PDB 4NN2) binds three Zn2+ ions through its ePHD finger
Comment:The extended PHD finger is characterized by Cys2HisCys5HisCys2His.
Jiyao W et al.(2023). "The conserved domain database in 2023.",