Swi / Snf chromatin-remodeling

Mahmoudi T, Parra M, Vries RG, Kauder SE, Verrijzer CP, Ott M, Verdin E (2006) The SWI/SNF chromatin-remodeling complex is a cofactor for Tat transactivation of the HIV promoter. J Biol... 

Treand C, du Chene I, Bres V, Kieman R, Benarous R, Benkirane M, Emdiani S (2006) Requirement for SWI/SNF chromatin-remodeling complex in Tat-mediated activation of the HIV-1 promoter. EMBO J 25(8) 1690-1699... 

Smith, C.L., Horowitz-Scherer, R., Flanagan, J.F., Woodcock, C.L., and Peterson, C.L. (2003) Structural analysis of the yeast SWI/SNF chromatin remodeling complex. Nat. Struct. Biol. 10, 141-145. 

Hara, R. and Sancar, A. (2002) The SWI/SNF chromatin-remodeling factor stimulates repair by human excision nuclease in the mononucleosome core particle. Mol. Cell. Biol. 22, 6779-6787. 

Wallberg, A.E., Neely, K.E., Hassan, A.H., Gustafsson, J.A., Workman, J.L., and Wright, A.P. (2000) Recruitment of the SWI-SNF chromatin remodeling complex as a mechanism of gene activation by the glucocorticoid receptor taul activation domain. Mol. Cell. Biol. 20, 2004-2013. 

Sarnowski, T.J., Swiezewski, S., Pawlikowska, K., Kaczanowski, S., and Jerzmanowski, A. (2002) AtSWBB, an Arabidopsis homolog of SWI3, a core subunit of yeast Swi/Snf chromatin remodeling complex, interacts with FCA, a regulator of flowering time. Nucleic Acids Res. 30, 3412-3421. 

Garcia-Pedrero JM, et al. The SWI/SNF chromatin remodeling subunit B AF57 is a critical regulator of estrogen receptor function in breast cancer cells. J. Biol. Chem. 2006 281 22656-22664. 

SWI/SNF chromatin-remodeling factors constitute another type of co-activator. These multisubunit complexes can transiently dissociate DNA from histone cores in an ATP-dependent reaction and may also decondense regions of chromatin, thereby promoting the binding of DNA-binding proteins needed for initiation to occur at some promoters. 

The myogenic program driven by MRFs depends on the Swi/Snf chromatin-remodeling complex, which makes target genes accessible. 

Mutations affecting the Swi/Snf chromatin-remodeling complex, which participates in transcriptional control, are associated with a variety of tumors. In some cases, interaction of the Swi/Snf complex with a nuclear tumor-suppressor protein may have a repressing effect on gene expression. 

Fig. 7. Model for the role of chromatin remodeling by SWI/SNF in excision repair. Two pathways are presented repair factors first or SWI/SNF first. To the left is a pathway in which damage recognition factors assemble at the damage site and then recruit SWI/ SNF to remodel the nudeosome. To the right is an alternative pathway in which remodeling by SWI/SNF accelerates the assembly of repair factors at the damage site. In both cases, dual incisions require the full complement of repair factors, as illustrated in Fig. 4, and after repair synthesis, the nucleosomes are reassembled. (See Color Insert.)...

Pereira LA, Bentley K, Peelers A, ChurchiU MJ, Deacon NJ (2000) A compilation of cellular transcription factor interactions with the HIV-1 LTR promoter. Nucleic Acids Res 28(3) 663-668 Persaud D, Zhou Y, Siliciano JM, Siliciano RF (2003) Latency in human immunodeficiency virus type 1 infection no easy answers. J Virol 77(3) 1659-1665 Peterson CL, Tamkun JW (1995) The SWI-SNF complex a chromatin remodeling machine Trends Biochem Sci 20(4) 143-146... 

WUson CJ, Chao DM, Imbalzano AN, Schnitzler GR, Kingston RE, Young RA (1996) RNA polymerase II holoenzyme contains SWI/SNF regulators involved in chromatin remodeling. Cell 84(2) 235-244... 

Helicases catalyze the processive separation of duplex DNA into single strands. Despite sharing similarity to helicases, none of the chromatin remodelling factors, with the exception of the INO80 complex, have been shown to catalyze the separation of DNA strands (Shen et al, 2000). Instead, they can translocate on double-stranded (ds) DNA in an ATP-hydrolysis dependent manner and are characterized by their ability to generate superhelical torsional strain in DNA (Havas et al, 2000 Saha et al, 2002 Whitehouse et al, 2003). The crystal structure of Rad54, a member of the SWI/SNF family has been solved for both S. solfataricus and zebrafish which helps to understand the mechanism of the SWI/SNF ATPase domain in remodelling processes (Durr et al, 2005 Thoma et al, 2005). It reveals... 

Whitehouse 1, Stockdale C, Haus A, Szczelkun MD, Owen-Hughes T (2003) Evidence for DNA translocation by the ISWl chromatin-remodeling enzyme. Mol Cell Biol 23 1935—1945 Wong AK, Shanahan E, Chen Y, Lian L, Ha P, Hendricks K, Ghaffari S, lliev D, Penn B, Woodland AM et al (2000) BRG1, a component of the SWI-SNF complex, is mutated in multiple human mmor cell lines. Cancer Res 60 6171—6177... 

Figure 1. Nucleolin acts as a histone chaperone and boosts the activity of chromatin remodeler SWI/SNF. (a) In vitro histone deposition assay shows the histone chaperone activity of nucleolin. Recombinant core histones were incubated with 5S 147 bp DNA in presence or absence of nucleolin. Note the disappearance of aggregates in the wells and the formation of nucleosomal particles in presence of increasing amount of nucleolin. (b) Sliding assay performed on centrally positioned 601 nucleosomes (250bp). The amount of SWI/SNF used here is insufficient to slide the nucleosomes. Note that in presence of nucleolin even the suboptimal quantity of SWI/SNF is able to slide the nucleosomes...

Martens JA, Winston E (2003) Recent advances in understanding chromatin remodeling by Swi/Snf complexes. Curr Opin Genet Dev 13 136-142... 

---