THE VOLE OF THYMIDYLATE SYNTHASE AS AN RNA-BINDING PROTEIN

Thymidylate synthase plays a central role in the biosynthesis of thymi dylate, an essential precursor for DNA biosynthesis. in addition to it s role in catalysis and cellular metabolism, it is now appreciated tha t thymidylate synthase functions as an RNA binding protein. Specifical ly, thymidylate synthase binds with high affinity to its own mRNA, res ulting in translational repression. An extensive series of experiments has been performed to elucidate the molecular elements underlying the interaction between thymidylate synthase and its own mRNA. In additio n to characterization of the underlying cis- and trans-acting elements , recent studies have shown that thymidylate synthase has the capacity to bind specifically to other cellular RNA species. While the biologi cal significance of these other RNA/thymidylate synthase interactions remains to be defined, this work suggests a potential role for TS in c oordinately regulating several critical aspects of cellular metabolism .