B-WICH complex binds rDNA promoter

Stable Identifier
Reaction [binding]
Homo sapiens
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Active rRNA genes are bound by the B‑WICH multiprotein complex (Cavellan et al. 2006, Percipalle et al. 2006). B-WICH binds the promoter region of the gene (Percipalle et al. 2006, Sarshad et al. 2013). The MYO1C component of the B-WICH complex binds chromatin and interacts with SMARCA5. Binding causes 200 bp of chromatin at the promoter to adopt a more open configuration and contributes to epigenetic modifications compatible with transcription activation (Vintermist et al. 2011, Sarshad et al. 2013). At the rRNA gene promoter the SMARCA5-MYOIC interaction is excluded when MYOIC interacts with actin in complex with RNA polymerase I (Sarshad et al. 2013). Binding of MYOIC to chromatin is regulated by GSK3beta-dependent phosphorylation that targets the MYOIC chromatin binding domain (Sarshad et al. 2014). Binding of MYOIC to the RNA polymerase I is partly mediated via phosphorylated TIF1A (Philimonenko et al. 2004). Binding of B‑WICH to rRNA genes requires MYOIC to be recruited to active rRNA genes and this mechanism appears to be a requirement to activate and maintain transcription by RNA polymerase I (Percipalle et al. 2006, Sarshad et al. 2013, Sarshad et al. 2014, reviewed in Sarshad and Percipalle 2014).

Literature References
PubMed ID Title Journal Year
16514417 The chromatin remodelling complex WSTF-SNF2h interacts with nuclear myosin 1 and has a role in RNA polymerase I transcription

Percipalle, P, Fomproix, N, Cavellán, E, Voit, R, Reimer, G, Krüger, T, Thyberg, J, Scheer, U, Grummt, I, Farrants, AK

EMBO Rep. 2006
16603771 The WSTF-SNF2h chromatin remodeling complex interacts with several nuclear proteins in transcription

Cavellán, E, Asp, P, Percipalle, P, Farrants, AK

J. Biol. Chem. 2006
21559432 The chromatin remodelling complex B-WICH changes the chromatin structure and recruits histone acetyl-transferases to active rRNA genes

Vintermist, A, Böhm, S, Sadeghifar, F, Louvet, E, Mansén, A, Percipalle, P, Ostlund Farrants, AK

PLoS ONE 2011
24901984 Glycogen synthase kinase (GSK) 3β phosphorylates and protects nuclear myosin 1c from proteasome-mediated degradation to activate rDNA transcription in early G1 cells

Sarshad, AA, Corcoran, M, Al-Muzzaini, B, Borgonovo-Brandter, L, Von Euler, A, Lamont, D, Visa, N, Percipalle, P

PLoS Genet. 2014
24952918 New insight into role of myosin motors for activation of RNA polymerases

Sarshad, AA, Percipalle, P

Int Rev Cell Mol Biol 2014
15558034 Nuclear actin and myosin I are required for RNA polymerase I transcription

Philimonenko, VV, Zhao, J, Iben, S, Dingová, H, Kyselá, K, Kahle, M, Zentgraf, H, Hofmann, WA, de Lanerolle, P, Hozák, P, Grummt, I

Nat. Cell Biol. 2004
23555303 Nuclear myosin 1c facilitates the chromatin modifications required to activate rRNA gene transcription and cell cycle progression

Sarshad, A, Sadeghifar, F, Louvet, E, Mori, R, Böhm, S, Al-Muzzaini, B, Vintermist, A, Fomproix, N, Östlund, AK, Percipalle, P

PLoS Genet. 2013
This event is regulated
Positively by

Nuclear myosin 1 is positively regulated by the glycogen synthase kinase (GSK3beta) by direct phosphorylation (Sarshad et al. 2014). NM1 phosphorylation is a requirement for NM1 to bind to the chromatin. In the absence of GSK3beta dependent phosphorylation NM1 is polyubiquitinated by the E3 ligase UBR5 and degraded by the proteasome and rRNA synthesis is not activated (Sarshad et al. 2014).

Orthologous Events
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