Snf1 Kinases with Different β-Subunit Isoforms Play Distinct Roles in Regulating Haploid Invasive Growth

Abstract

The Snf1 protein kinase of Saccharomyces cerevisiae has been shown to have a role in regulating haploid invasive growth in response to glucose depletion. Cells contain three forms of the Snf1 kinase, each with a different ␤-subunit isoform, either Gal83, Sip1, or Sip2. We present evidence that different Snf1 kinases play distinct roles in two aspects of invasive growth, namely, adherence to the agar substrate and filamentation. The Snf1-Gal83 form of the kinase is required for adherence, whereas either Snf1-Gal83 or Snf1-Sip2 is sufficient for filamentation. Genetic evidence indicates that Snf1-Gal83 affects adherence by antagonizing Nrg1-and Nrg2-mediated repression of the FLO11 flocculin and adhesin gene. In contrast, the mechanism(s) by which Snf1-Gal83 and Snf1-Sip2 affect filamentation is independent of FLO11. Thus, the Snf1 kinase regulates invasive growth by at least two distinct mechanisms.

β-Subunits of the SnRK1 Complexes Share a Common Ancestral Function Together with Expression and Function Specificities; Physical Interaction with Nitrate Reductase Specifically Occurs via AKINβ1-Subunit

“…These data suggest that b-subunits might play a major role in the regulation and specialization of the SNF1 complexes. For instance, SNF1 complexes have been involved in various aspects of the invasive filamentous yeast growth depending on the b-subunit integrated in the complex (Vyas et al, 2003).…”

Isolation and characterization of the carbon catabolite‐derepressing protein kinase Snf1 from the stress tolerant yeast Torulaspora delbrueckii

“…The activity of the protein kinase complex SNF1 is also essential in different cellular responses and processes activated by nutrient deprivation, such as glycogen accumulation (Thompson-Jaeger et al, 1991), sporulation (Honigberg and Lee, 1998), aging (Ashrafi et al, 2000) or invasive growth (Vyas et al, 2003). Evidence also suggests that SNF1 plays a key role in the response of yeast cells to a variety of environmental stresses.…”

Adaptation of the Osmotolerant Yeast Zygosaccharomyces rouxii to an Osmotic Environment Through Copy Number Amplification of FLO11D

“…The regulation of FLO11 is remarkably complex. At least three well-known signaling cascades regulate FLO11 expression in response to environment changes: the Ras-cAMP pathway, the MAP kinasedependent filamentous growth pathway, and the glucose repression pathway (Madhani and Fink 1997;Rupp et al 1999;Gagiano et al 2002;Kuchin et al 2002;Vyas et al 2003;Schwartz and Madhani 2004;Verstrepen and Klis 2006). Accordingly, FLO11-dependent flor formation is considered as an adaptation to nutrient-limited and anoxic conditions because flor formation enables yeast to continue its growth through the utilization of oxygen and ethanol, which are produced by the yeast itself.…”