Structure and Regulation of a Candida Albicans RP10 Gene Which Encodes an Immunogenic Protein Homologous to Saccharomyces Cerevisiae Ribosomal Protein 10

The Candida albicans clone cDNA10 was isolated on the basis that it encodes a protein which is immunogenic during infections in humans (R. K. Swoboda, G. Bertram, H. Hollander, D. Greenspan, J. S. Greenspan, N. A. R. Gow, G. W. Gooday, and A. J. P. Brown, Infect. Immun. 61:4263-4271, 1993). cDNA10 was used to isolate its cognate gene, and both the cDNA and gene were sequenced, revealing a major open reading frame with the potential to encode a basic protein of 256 amino acids with a predicted molecular weight of 29 kDa. Over its entire length, the open reading frame showed strong homology at both the nucleic acid (75 to 78%) and amino acid (79 to 81%) levels to two Saccharomyces cerevisiae genes encoding the 40S ribosomal protein, Rp10. Therefore, our C. albicans gene was renamed RP10. Northern (RNA) analyses in C. albicans 3153 revealed that RP10 expression is regulated in a manner very similar to that of S. cerevisiae ribosomal genes. The level of the RP10 mRNA decreased upon heat shock (from 25 to 45 degrees C) and was tightly regulated during growth. Maximal levels of the mRNA were reached during mid-exponential phase before they decreased to negligible levels in stationary phase. The level of the RP10 mRNA was induced only transiently during the yeast-to-hyphal morphological transition but did not appear to respond to hyphal development per se.