RNA polymerase III (Pol III) transcription is regulated by modifications of the 
chromatin. DNA methylation and post-translational modifications of histones, 
such as acetylation, phosphorylation and methylation have been linked to Pol III 
transcriptional activity. In addition to being regulated by modifications of DNA 
and histones, Pol III genes and its transcription factors have been implicated 
in the organization of nuclear chromatin in several organisms. In yeast, the 
ability of the Pol III transcription system to contribute to nuclear 
organization seems to be dependent on direct interactions of Pol III genes 
and/or its transcription factors TFIIIC and TFIIIB with the structural 
maintenance of chromatin (SMC) protein-containing complexes cohesin and 
condensin. In human cells, Pol III genes and transcription factors have also 
been shown to colocalize with cohesin and the transcription regulator and genome 
organizer CCCTC-binding factor (CTCF). Furthermore, chromosomal sites have been 
identified in yeast and humans that are bound by partial Pol III machineries 
(extra TFIIIC sites - ETC; chromosome organizing clamps - COC). These ETCs/COC 
as well as Pol III genes possess the ability to act as boundary elements that 
restrict spreading of heterochromatin.