Phenotypic analysis of homozygous diploid mutants corresponding to a subset of Sks1p-dependent phosphoproteins identified by mass spectrometry.

<p>A) The indicated homozygous diploid deletion mutants exhibit surface-spread pseudohyphal filamentation phenotypes on SLAD and SLALD medium relative to a wild-type strain. The degree of observed pseudohyphal growth is indicated, with the “−” corresponding to an absence of filamentation and “+++” indicating the strongest observed pseudohyphal growth. Scale bars representing 2 mm are indicated. The <i>pda1</i>Δ/Δ strain formed slightly smaller colonies than wild type, and <i>npr3</i>Δ/Δ mutants formed markedly small colonies. B) Amino acid sequences identifying Sks1p-dependent phosphorylation sites selected for further phenotypic analysis. The ratio indicates abundance upon phosphopeptide enrichment from the <i>sks1-K39R</i> mutant relative to wild-type. All homozygous diploid integrated point mutants demonstrated a significant fitness defect compared to wild-type when grown in liquid media under nitrogen-limiting (SLAD) or nitrogen- and glucose-limiting (SLALD) conditions as indicated by C) the long-term cell titer and D) growth curves for each condition. Full values for the growth curves shown here are provided in Supplementary <a href="http://www.plosgenetics.org/article/info:doi/10.1371/journal.pgen.1004183#pgen.1004183.s005" target="_blank">Tables S3</a> through <a href="http://www.plosgenetics.org/article/info:doi/10.1371/journal.pgen.1004183#pgen.1004183.s008" target="_blank">S6</a>.