PHD finger 2 found in Lysine-specific demethylase KDM5A, KDM5B, KDM5C, KDM5D, and similar proteins
The JARID subfamily within the JmjC proteins includes Lysine-specific demethylase KDM5A, KDM5B, KDM5C, KDM5D and a Drosophila homolog protein, little imaginal discs (Lid). KDM5A was originally identified as a retinoblastoma protein (Rb)-binding partner and its inactivation may be important for Rb to promote differentiation. It is involved in transcription through interacting with TBP, p107, nuclear receptors, Myc, Sin3/HDAC, Mad1, RBP-J, CLOCK, and BMAL1. KDM5B has a restricted expression pattern in the testis, ovary, and transiently in the mammary gland of the pregnant female and has been shown to be upregulated in breast cancer, prostate cancer, and lung cancer, suggesting a potential role in tumorigenesis. Both KDM5A and KDM5B function as trimethylated histone H3 lysine 4 (H3K4me3) demethylases. KDM5C 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 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. The family also includes Drosophila melanogaster protein little imaginal discs (Lid) that functions as a JmjC-dependent trimethyl histone H3K4 (H3K4me3) demethylase, which is required for dMyc-induced cell growth. It positively regulates Hox gene expression in S2 cells. Members in this family 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 or three plant homeodomain (PHD) fingers. This model corresponds to the second PHD finger.
Jiyao W et al.(2023). "The conserved domain database in 2023.",