Filamentation Regulatory Pathways Control Adhesion-Dependent Surface Responses in Yeast

Abstract

Signaling pathways can regulate biological responses by the transcriptional regulation of target genes. In yeast, multiple signaling pathways control filamentous growth, a morphogenetic response that occurs in many species including fungal pathogens. Here, we examine the role of signaling pathways that control filamentous growth in regulating adhesion-dependent surface responses, including mat formation and colony patterning. Expression profiling and mutant phenotype analysis showed that the major pathways that regulate filamentous growth [filamentous growth MAPK (fMAPK), RAS, retrograde (RTG), RIM101, RPD3, ELP, SNF1, and PHO85] also regulated mat formation and colony patterning. The chromatin remodeling complex, SAGA, also regulated these responses. We also show that the RAS and RTG pathways coregulated a common set of target genes, and that SAGA regulated target genes known to be controlled by the fMAPK, RAS, and RTG pathways. Analysis of surface growth-specific targets identified genes that respond to low oxygen, high temperature, and desiccation stresses. We also explore the question of why cells make adhesive contacts in colonies. Cell adhesion contacts mediated by the coregulated target and adhesion molecule, Flo11p, deterred entry into colonies by macroscopic predators and impacted colony temperature regulation. The identification of new regulators (e.g., SAGA), and targets of surface growth in yeast may provide insights into fungal pathogenesis in settings where surface growth and adhesion contributes to virulence.

New Aspects of Invasive Growth Regulation Identified by Functional Profiling of MAPK Pathway Targets in Saccharomyces cerevisiae

“…This suggests Nfg1p, Rgd2p, Rpi1p, and Tip1p might not turn off invasive growth like Dig1p, but instead modulate it in a specific context. One way the fMAPK pathway regulates invasive growth is by regulating the expression of FLO11, which encodes the cells' major adhesion molecule (LO AND DRANGINIS 1996;MADHANI et al 1999;RUPP et al 1999;ROBERTS et al 2000;HALME et al 2004;BORNEMAN et al 2006;VEELDERS et al 2010;ADHIKARI AND CULLEN 2014;KRAUSHAAR et al 2015;BARUA et al 2016;REYNOLDS 2018;CHOW et al 2019b;BRUCKNER et al 2020). RT-qPCR analysis showed that the expression of FLO11 was elevated in the nfg1∆, rgd2∆, and tip1∆ mutants compared to wild type, indicating these genes have an inhibitory effect on FLO11 expression (Fig.…”

“…Transcriptional targets of the fMAPK pathway have been identified by comparative expression profiling (MADHANI et al 1999;ROBERTS et al 2000;HEISE et al 2010; ADHIKARI AND CULLEN 2014; VAN DER FELDEN et al 2014;CHOW et al 2019b). In Adhikari et al 2014, wild- (CULLEN et al 2004;VADAIE et al 2008;PITONIAK et al 2009)], KSS1 [MAP kinase, (COURCHESNE et al 1989;ROBERTS AND FINK 1994;BARDWELL et al 1998a)], STE12 and TEC1 LALOUX et al 1990;CHOU et al 2006), are induced by the fMAPK pathway to generate positive feedback (Fig.…”

“…Many adhesion-dependent responses are regulated by the fMAPK pathway (CHOW et al 2019b). For example, cells can form adherent flocs in liquid culture (VERSTREPEN et al 2003;HALME et al 2004;FIDALGO et al 2006;BARUA et al 2016).…”

“…1A, (GIMENO et al 1992;GIMENO AND FINK 1994;BORNEMAN et al 2006;HEISE et al 2010;CULLEN AND SPRAGUE 2012; VAN DER FELDEN et al 2014)]. These proteins induce the expression of many target genes (MADHANI et al 1999;ROBERTS et al 2000;HEISE et al 2010; ADHIKARI AND CULLEN 2014; VAN DER FELDEN et al 2014;CHOW et al 2019b;ZHOU et al 2020). Several highly induced targets of the fMAPK pathway positively regulate filamentous growth, such as BUD8, which encodes a protein involved in bud-site-selection at the distal pole [Fig.…”

Spatiotemporal Control of Pathway Sensors and Cross-Pathway Feedback Regulate a Cell Differentiation MAPK Pathway in Yeast

“…Relative gene expression was calculated using the 2 − Δ Ct formula, where Ct is defined as the cycle at which fluorescence was determined to be statistically significant above background; ΔCt is the difference in Ct of the gene of interest and the housekeeping gene ( ACT1). The primers used were: MSB2 forward (5′-CACTGCAAGCAGGTGGCTCT-3′), MSB2 reverse (5′-GAGGAGCCCGACAGTGTTGC-3′); HKR1 forward (5′-AAACCATGGGCGAAAATGGC-3′), HKR1 Reverse (5′-AAGGCAGGGGCTGTGAATAC-3′); KSS1 forward (5′-CCCAAGTGATGAGCCGGAAT-3′), KSS1 reverse (5′-TGGGCACTTCTTCCTCCTCT-3′); SHO1 forward (5′-AACTACGATGGGAGACACTTTG-3′), SHO1 reverse (5′-TCGTAAGCATCATCGTCATCAG-3′) (A dhikari and C ullen 2014); TEC1 forward (5′-ATGTTTCCAGAAGCCGTAGTT-3′), TEC1 reverse (5′-TTTAGCACCCAGTCCAGTATTT-3′) (A dhikari and C ullen 2014); STE12 forward (5′-GCAATCTTACCCAAACGGAATG-3′), STE12 reverse (5′-AATCGTCCGCGCCATAAA-3′) (A dhikari and C ullen 2014); FLO11 forward (5′-CACTTTTGAAGTTTATGCCACACAAG-3′), FLO11 reverse (5′-CTTGCATATTGAGCGGCACTAC-3′) (C hen and F ink 2006) and ACT1 forward (5′-TGGATTCCGGTGATGGTGTT-3′), ACT1 reverse (5′-CGGCCAAATCGATTCTCAA-3′) (C how et al 2019b). Experiments were performed with two independent biological replicates and two technical replicates for each biological replicate.…”