Fig 1.

Regulatory factors that influence expression of two major virulence factors, melanin and capsule. The GATA factors Cir1, Gat201, and Gat1, along with Tup1, show a reciprocal regulation of capsule and melanin. As described in the text and Table 1, many of the regulators directly or indirectly influence the expression of iron uptake functions, including Cir1, Gat201, Nrg1, Rim101, Sre1, Tup1, and Cuf1 (blue background). In addition, Cir1, Rim101, Sre1, Tup1, and Cuf1 influence copper homeostasis (gray background). However, as also indicated in Table 1, these factors influence the expression of genes in many other functional categories. The impact on capsule and melanin is shown for all of the factors in the serotype A background, based on the phenotypes of the corresponding mutants. The photographs show a highly melanized colony of C. neoformans grown on medium containing l-3,4-dihydroxyphenylalanine (∼4 mm in diameter) and a cell stained for capsule polysaccharide with India ink (∼10 μm in diameter).