Encodes an E3 ubiquitin ligase involed in monoubiquitination of H2B.
Remarks:hub1 and hub2 mutations do not lead to additive flowering-time phenotypes. [Gu et al., 2009][Cao et al., 2008]Single mutant:hub2 single mutant is early flowering under both SD and LD conditions. [Gu et al., 2009][Cao et al., 2008][Dhawan et al., 2009]Function:E3 ubiquitin-protein ligase that monoubiquitinates H2B to form H2BK143ub1. H2BK143ub1 gives a specific tag for epigenetic transcriptional activation and is also prerequisite for H3K4me and maybe H3K79me. It thereby plays a central role in histone code and gene regulation. Forms a ubiquitin ligase complex in cooperation with the E2 enzyme UBC2/RAD6. [Data from UniProt]