PHD finger 2 found in Lysine-specific demethylase 5C (KDM5C) and 5D (KDM5D)
The family includes KDM5C and KDM5D, both of which belong to the JARID subfamily within the JmjC proteins. KDM5C (also termed Histone demethylase JARID1C, Jumonji/ARIDdomain-containing protein 1C, SmcX, or Xe169) is a H3K4 trimethyl-histone demethylase that catalyzes demethylation of H3K4me3 and H3K4me2 to H3K4me1. It plays a role in neuronal survival and dendrite development. KDM5C defects are associated with X-linked mental retardation (XLMR). KDM5D (also termed Histocompatibility Y antigen (H-Y), Histone demethylase JARID1D, Jumonji/ARID domain-containing protein 1D, or SmcY) is a male-specific antigen that shows a demethylase activity specific for di- and tri-methylated histone H3K4 (H3K4me3 and H3K4me2), and has a male-specific function as a histone H3K4 demethylase by recruiting a meiosis-regulatory protein, MSH5, to condensed DNA. KDM5D directly interacts with a polycomb-like protein Ring6a/MBLR, and plays a role in regulation of transcriptional initiation through H3K4 demethylation. Both KDM5C and KDM5D contain the catalytic JmjC domain, JmjN, the BRIGHT domain, which is an AT-rich interacting domain (ARID), and a Cys5HisCys2 zinc finger, as well as two plant homeodomain (PHD) fingers. This model corresponds to the second PHD finger.
Jiyao W et al.(2023). "The conserved domain database in 2023.",