Enhanced Secretion of Cell Wall Bound Enolase into Culture Medium by the sool-l Mutation of Saccharomyces cerevisiae

In order to identify the protein(s) secreted into culture medium by the sool-l/retl-l mutation of Saccharomyces cerevisiae, proteins from the culture medium of cells grown at permissive (28$^{\circ}C$) and non-permissive temperatures (37$^{\circ}C$), were analyzed. Comparison of protein bands separated by SDS-PAGE identified a prominent band of 47-kDa band from a mutant grown at 37$^{\circ}C$. N-terminal amino acid sequencing of this 47-kDa protein showed high identity with enolases 1 and 2. Western blot analysis revealed that most of the cell wall-bound enolase was released into the culture medium of the mutant grown at 37$^{\circ}C$, some of which were separated as those with lower molecular weights. Our results, presented here, indicate the impairment of cell wall enolase biogenesis and assembly by the sool-l/retl-l mutation of S. cerevisiae.