TABLE 1.
Cellular function and main interactors of polyQ SCA proteins.
| Disease | Causative gene/protein | Cellular function of disease associated protein | Main interactors | Cellular function | References |
| SCA1 | ATXN1/ataxin-1 (ATXN1) | Transcription; RNA metabolism | ATXN1L (BOAT) | Transcription; corepressor | Mizutani et al., 2005; Bowman et al., 2007 |
| CIC | Transcriptional repressor | Lim et al., 2008; Rousseaux et al., 2018 | |||
| HDAC3 | Histone deacetylation, epigenetic repressor | Venkatraman et al., 2014 | |||
| LANP | Inhibitor of histone acetyltransferases | Matilla et al., 1997; Cvetanovic et al., 2007, 2012 | |||
| PQBP-1 | Transcription; splicing | Okazawa et al., 2002 | |||
| RBM17 | Splicing | Lim et al., 2008 | |||
| RORa/TIP60 | Transcriptional activation | Serra et al., 2006 | |||
| SMRT/NCOR2 | Transcriptional corepressor | Tsai et al., 2004 | |||
| SCA2 | ATXN2/ataxin-2 (ATXN2) | RNA metabolism; translation | PABP-1 | mRNA splicing and stability | Satterfield and Pallanck, 2006 |
| A2BP1/Fox1 | Splicing | Shibata et al., 2000 | |||
| DDX6 | RNA degradation | Nonhoff et al., 2007 | |||
| TDP-43 | RNA processing; transcription | Elden et al., 2010 | |||
| SCA3 | ATXN3/ataxin-3 (ATXN3) | Deubiquitinase; transcriptional regulator | CBP/PCAF/P300 | Histone acetylation | Chai et al., 2001; Li et al., 2002 |
| HDAC3/NCOR | Histone deacetylation | Evert et al., 2006; Feng et al., 2018 | |||
| FOXO4 | Transcriptional activation | Araujo et al., 2011 | |||
| TBP | Basal transcription | Araujo et al., 2011 | |||
| PML | Nuclear bodies | Chai et al., 2001 | |||
| SCA6 | CACNA1A/α1A subunit of Cav2.1 and α1ACT | Calcium channel subunit and transcriptional activator | AT-rich and CA-rich DNA elements | Enhancers | Du et al., 2013 |
| SCA7 | ATXN7/ataxin-7 (ATXN7) | SAGA component; co-activator of RNAPII-driven transcription | GCN5 | Histone acetylation | Helmlinger et al., 2004 |
| USP22 | Histone deubiquitinase | Helmlinger et al., 2004 | |||
| CRX | Transcriptional activation | La Spada et al., 2001; Chen S. et al., 2004 | |||
| RORa | Transcriptional activation | Strom et al., 2005 | |||
| SIRT1 | Deacetylase | Stoyas et al., 2019 | |||
| TBP | Basal transcription | Papai et al., 2020 | |||
| SCA17 | TBP/TATA-box binding protein (TBP) | TFIID component; basal transcription | DNA elements | Promoter regions | Friedman et al., 2008 |
| TFIIB | General transcription | Friedman et al., 2007 | |||
| XBP1 | Transcriptional activation | Yang et al., 2014 | |||
| MYOD | Transcriptional activation | Heller and Bengal, 1998 | |||
| SP1 | Transcriptional activation | Shah et al., 2009 |