A CANDIDA-ALBICANS 37 KDA POLYPEPTIDE WITH HOMOLOGY TO THE LAMININ RECEPTOR IS A COMPONENT OF THE TRANSLATIONAL MACHINERY

A cDNA encoding a 37 kDa protein was isolated from an expression libra ry using antibodies raised against mycelial cell walls from Candida al bicans. The 37 kDa protein has over 60% sequence identity with the 37 kDa laminin-binding protein (LBP) from humans and over 80% identity wi th the Yst proteins of Saccharomyces cerevisiae. The C. albicans prote in was named CaYst1. It was found in membrane and ribosome fractions b ut surprisingly, was not found in cell walls. Unlike the human LBP, Ca Yst1p does not bind laminin. These data indicate that CaYst1p is not a cell-surface receptor for laminin as has been proposed for the human LBP. Instead, like the S. cerevisiae Yst proteins, it appears to be a ribosomal protein. This conclusion is supported by the finding that Ca YST1-cDNA complements the lethal phenotype linked to the disruption of both YST genes in S. cerevisiae.