M. Bodmer-glavas et al., RNA polymerase II and III transcription factors can stimulate DNA replication by modifying origin chromatin structures, NUCL ACID R, 29(22), 2001, pp. 4570-4580
Many transcription factors are multifunctional and also influence DNA repli
cation. So far, their mechanism of action has remained elusive. Here we sho
w that a DNA-binding protein could rely on the same biochemical activity th
at activates transcription to stimulate replication from the yeast chromoso
mal ARS1 origin. Unexpectedly, the ability to stimulate replication from th
is origin was not restricted to polymerase II transcription factors, but wa
s a property shared by polymerase III factors. Furthermore, activation of r
eplication did not depend on the process of transcription, but rather on th
e ability of DNA-binding transcription factors to remodel chromatin. The na
tural ARS1 activator Abf1 and the other transcription factors that stimulat
ed replication remodeled chromatin in a very similar manner. Moreover, the
presence of a histone H3 mutant that was previously shown to generally incr
ease transcription also facilitated replication from ARS1 and partially com
pensated for the absence of a transcription factor. We propose that multifu
nctional transcription factors work by influencing the chromatin architectu
re at replication origins so as to generate a structure that is favorable t
o the initiation of replication.