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Functional Interactions of WSC1 , TOR and PKC1 in myo1Δ strains of Saccharomyces cerevisiae
Author(s) -
PaganMercado Glorivee,
SantiagoCartagena Ednalise,
RodríguezMedina José R.
Publication year - 2011
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.25.1_supplement.961.4
Subject(s) - cytokinesis , phosphorylation , saccharomyces cerevisiae , mutant , regulator , microbiology and biotechnology , chemistry , biology , genetics , cell division , gene , cell
The Saccharomyces cerevisiae myosin type II null strain ( myo1Δ ) is a cytokinesis mutant that exhibits regulation of both the TOR and PKC1 stress signaling pathways. Our objective was to assess if these pathways share upstream regulators for mounting the stress response in myo1Δ strains. To address this question, we tested for TOR1 activity in null mutants of the Wsc family of plasma membrane stress sensors carrying the myo1Δ mutation, by analyzing the phosphorylation state of Npr1p. The activation of PKC1 was monitored in these strains by the level of Mpk1p/Slt2p phosphorylation. We then analyzed the functional interaction between TOR2 and PKC1 by testing the levels of phosphorylated‐Mpk1p/Slt2p in a TOR2‐21 ts myo1Δ strain at the restrictive temperature. The results show that the double mutant wsc1Δmyo1Δ activated Tor1p, which was previously repressed in the myo1Δ strain, and up regulated Mpk1p/Slt2p phosphorylation. Synthetic rescue of TOR2‐21 ts lethality by myo1Δ was observed along with up regulation of Mpk1p/Slt2p phosphorylation. We conclude that WSC1 , an upstream regulator of PKC1 , is involved in cross‐talk with TOR1 . Synthetic rescue of TOR2‐21 ts lethality by myo1Δ suggests the activation of Tor2p‐redundant function(s) in the myo1Δ cytokinesis mutant. Supported by NIGMS‐NIAID (SC1AI081658‐03), NCRR‐RCMI (G12RR03051) and MBRS‐RISE (R25GM061838).