This entry includes a group of F-box-like/WD repeat-containing proteins, including Hif2/Sif2 from yeasts, Ebi from Drosophila melanogaster, TBL1X /TBL1XR1 from humans and HOS15 from Arabidopsis. Hif2/Sif2 is part of the set3 histone deacetylase complex involved in chromatin remodeling and transcription regulation []. Ebi promotes the degradation of a repressor of neuronal differentiation (Ttk88) and also limits S phase entry []. TBL1X /TBL1XR1 act as a bridge between the corepressor protein and histones by interacting with both of them within the complex. The N terminus of TBL1X interacts with the N termini of both H2B and H4 histones, and the first three C-terminal WD40-repeats of TBL1X interact with the corepressor complex []. TBL1X /TBL1XR1 serve as specific adaptors for the recruitment of the ubiquitin conjugating/19S proteasome complex []and are important for both formation and dismantling of the NCOR complex, which is a corepressor complex. Mutations of the TBL1XR1 gene have been linked to several neurodevelopmental disorders, such as spanning from autism spectrum disorders (ASD), West syndrome, schizophrenia (SCZ), intellectual disability [].HOS15 represses genes associated with abiotic stress tolerance through histone deacetylation in Arabidopsis [].
