High impact information on SPOP

• We further demonstrate that MACROH2A1 deposition is regulated by the CULLIN3/SPOP ligase complex and is actively involved in stable X inactivation, likely through the formation of an additional layer of epigenetic silencing [1].
• Here, we report that the E3 ubiquitin ligase consisting of SPOP and CULLIN3 is able to ubiquitinate the Polycomb group protein BMI1 and the variant histone MACROH2A [1].
• Importantly, RNAi-mediated knock-down of CULLIN3 or SPOP results in loss of MACROH2A1 from the inactivated X chromosome (Xi), leading to reactivation of the Xi in the presence of inhibitors of DNA methylation and histone deacetylation [1].
• Data base searches revealed multiple proteins containing TDs homologous to those found in MUL, USP7, and SPOP throughout eukaryotes, including yeast, protists, plants, invertebrates, and mammals, suggesting that this branch of the TD family arose from an ancient gene [2].
• HA-tagged SPOP, transfected and overexpressed in COS7 cells, exhibited a discrete speckled pattern in the nuclei and was co-localized with the splicing factor, snRNP B'/B [3].

Biological context of SPOP

• Mutagenesis study suggests that the ability of SPOP to self-associate as well as its ability to bind with Daxx was important for the modulation of Daxx-mediated transcriptional repression [4].

Associations of SPOP with chemical compounds

• The COOH-terminal region of Daxx interacts with the NH2-terminal region of SPOP [4].

Other interactions of SPOP

• This is the first report on the biochemical and functional interactions between Daxx and SPOP [4].

References