THYMIDYLATE SYNTHASE IS LOCALIZED TO THE NUCLEAR PERIPHERY IN THE YEAST SACCHAROMYCES-CEREVISIAE

To date, the organization of DNA precursor synthesis within eukaryotic cells remains unresolved. Previous studies have suggested the existence of a multienzyme complex that is responsible for DNA precursor synthesis and is associated with sites of replication within the nucleus. Contrasting this, other studies have proposed that DNA precursor synthesis occurs outside the nucleus. To further these studies, we have addressed the location where thymidylate synthase resides in yeast. Subcellular fractionation experiments indicate thymidylate synthase is associated with purified nuclei. Consistent with this, immunofluorescence analysis suggests that thymidylate synthase is situated at the nuclear periphery.