Phosphomannosylation and the Functional Analysis of the Extended -Like Gene Family.

Phosphomannosylation is a modification of cell wall proteins that occurs in some species of yeast-like organisms, including the human pathogen . These modified mannans confer a negative charge to the wall, which is important for the interactions with phagocytic cells of the immune systems and cationic antimicrobial peptides. In , the synthesis of phosphomannan relies on two enzymes, the phosphomannosyltransferase Ktr6 and its positive regulator Mnn4.

Disruption of Protein Mannosylation Affects Cell Wall, Immune Sensing, and Virulence.

The fungal cell wall contains glycoproteins that interact with the host immune system. In the prominent pathogenic yeast , Pmr1 acts as a Golgi-resident ion pump that provides cofactors to mannosyltransferases, regulating the synthesis of mannans attached to glycoproteins. To gain insight into a putative conservation of such a crucial process within opportunistic yeasts, we were particularly interested in studying the role of the homolog in a low-virulent species that rarely causes candidiasis, .