"Chromosome kissing" and modulation of replication termination.

Previously, inter-chromosomal interactions called "chromosome kissing" have been reported to control tissue-specific transcription and cell fate determination. Using the fission yeast as a model system we have shown that physiologically programmed replication termination is also modulated by chromosome kissing. The published report reviewed here shows that a myb-like replication terminator protein Reb1 of S. pombe and its cognate binding sites (Ter) are involved in chromosome kissing that promotes a cooperative mechanism of replication termination. We also suggest that at least one other replication terminator protein namely Sap1, which is also an origin binding protein, is likely to be involved in a similar mechanism of control not only of fork arrest but also of replication initiation and in possible ori-Ter interaction. We discuss the roles of chromatin remodeling and other proteins in this novel mechanism of replication control.