Methionine biosynthesis and S-adenosylmethionine degradation during an induced morphogenesis of Candida albicans

Abstract

Seven strains of Candida albicans were used in studies designed to delineate altered biochemical activity during an induced yeast to filamentous morphogenesis. Four of the strains studied underwent a rapid (1–2 h) yeast to filamentous transformation in a defined medium with glycine as the main nitrogen source; three other strains of C. albicans remained yeast-like under the same growth conditions. Cell-free extracts, prepared from cells harvested after various time intervals of growth in glycine medium, were used to measure enzymic capacity to form methionine, via the enzyme S-adenosylmethionine (or methylmethionine) homocysteine methyltransferase, and degrade S-adenosylmethionine. Increased enzymic capacity to synthesize methionine (with S-adenosylmethionine as methyl donor) and degrade S-adenosylmethionine appeared to correlate best with a yeast to filamentous transformation of C. albicans. Intracellular S-adenosylmethionine content also decreased with time, in all seven strains, when the cells were cultured in the glycine medium. S-adenosylmethionine may play a key role in the biochemical alterations that occur during the morphogenesis of C. albicans.