Snf1 kinase complexes containing different beta subunits have
distinct roles in invasive growth and filamentation.
Valmik
K. Vyas, Sergei Kuchin, Cristin Berkey, Marian Carlson
Institute of Cancer Research, Columbia University, 701 West 168th St.,
New York, Ny 10032, USA
The Snf1 kinase has a role in regulating
haploid invasive growth in response to glucose depletion (Cullen and
Sprague, PNAS 97:13619, 2000). S. cerevisiae cells contain three
isoforms of the Snf1 kinase, each containing the catalytic alpha subunit
Snf1, the activating gamma subunit Snf4, and one of the three beta
subunits, Gal83, Sip1 or Sip2. The beta subunits have distinct, although
partially overlapping, functions and have roles in regulating the
specificity and subcellular localization of the kinase. We present
evidence that different beta subunits are required for invasion of agar,
as judged by plate washing assays, and for filamentation, as determined
by microscopic observation. Thus, the Snf1 kinase affects these
different aspects of invasive growth by distinct mechanisms. We show
that the isoform of the kinase containing Gal83, which becomes nuclear
localized in response to glucose limitation, affects agar invasion by a
mechanism involving the repressors Nrg1 and Nrg2 and transcriptional
control of FLO11.
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