InterPro domain: IPR045134

This entry includes UHRF1/2 from animals and ORTHRUS 1-5 from Arabidopsis. They are ubiquitin-like proteins with PHD and RING finger domains. UHRF1, also known as ICBP90, is a transcription and cell cycle regulator and a methyl K9 H3-specific binding protein [ 1 ]. UHRF2 is a ubiquitin E3 ligase for cell cycle proteins, such as CCND1 and CCNE1 [ 2 ]. It can also act as a SUMO E3 ligase for ZNF131 [ 3 ].

In plants, ORTHRUS family members are E3 ligases mediating DNA methylation status in vivo. ORTH1-ORTH5 are predicted to encode proteins that contain one plant homeodomain (PHD), two really interesting new gene (RING) domains, and one set ring associated (SRA) domain [ 4 ].

1. ICBP90, a novel methyl K9 H3 binding protein linking protein ubiquitination with heterochromatin formation. Mol Cell Biol 28, 705-17
2. NIRF constitutes a nodal point in the cell cycle network and is a candidate tumor suppressor. Cell Cycle 10, 3284-99
3. UHRF2, a ubiquitin E3 ligase, acts as a small ubiquitin-like modifier E3 ligase for zinc finger protein 131. J Biol Chem 288, 9102-11
4. ORTH/VIM proteins that regulate DNA methylation are functional ubiquitin E3 ligases. Plant J 56, 704-15