BACKGROUND: Dia2 is an F-box protein found in the budding yeast, S. cerevisiae. 
Together with Skp1 and Cul1, Dia2 forms the substrate-determining part of an E3 
ubiquitin ligase complex, otherwise known as the SCF. Dia2 has previously been 
implicated in the control of replication and genome stability via its 
interaction with the replisome progression complex.
PRINCIPAL FINDINGS: We identified components of the RSC chromatin remodelling 
complex as genetic interactors with Dia2, suggesting an additional role for Dia2 
in the regulation of transcription. We show that Dia2 is involved in controlling 
assembly of the RSC complex. RSC belongs to a group of ATP-dependent 
nucleosome-remodelling complexes that controls the repositioning of nucleosomes. 
The RSC complex is expressed abundantly and its 17 subunits are recruited to 
chromatin in response to both transcription activation and repression. In the 
absence of Dia2, RSC-mediated transcription regulation was impaired, with 
concomitant abnormalities in nucleosome positioning.
CONCLUSIONS: Our findings imply that Dia2 is required for the correct assembly 
and function of the RSC complex. Dia2, by controlling the RSC chromatin 
remodeller, fine-tunes transcription by controlling nucleosome positioning 
during transcriptional activation and repression.