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Assay for Adhesion and Agar Invasion in S. cerevisiae
04:36

Assay for Adhesion and Agar Invasion in S. cerevisiae

Published on: November 8, 2006

Involvement of Saccharomyces cerevisiae Avo3p/Tsc11p in maintaining TOR complex 2 integrity and coupling to

Hsiang-Ling Ho1, Hsin-Yi Lee, Hsien-Ching Liao

  • 1Institute of Biochemistry and Molecular Biology, School of Life Sciences, National Yang-Ming University, 155, Sec. 2, Li-Nong St., Taipei 11221, Taiwan.

Eukaryotic Cell
|June 17, 2008
PubMed

Insights

Investigating Saccharomyces TORC2 mutants revealed Avo3p acts as a crucial scaffold for TORC2 structure and signaling. Two distinct downstream pathways, one involving Avo1p and another Avo2p/Slm1p, converge on Rho1p activation.

Area of Science:

  • Cellular Biology
  • Molecular Biology
  • Biochemistry

Background:

  • Target-of-rapamycin proteins (TORs) are key regulators of cell growth, functioning in conserved TORC1 and TORC2 complexes.
  • The precise mechanisms of TORC2 action and regulation, particularly its role in cell integrity and actin organization, remain incompletely understood.
  • Saccharomyces TORC2 is a multiprotein complex essential for cellular processes.

Purpose of the Study:

  • To elucidate the specific functions of Avo3p within the Saccharomyces TORC2 complex.
  • To differentiate the downstream signaling mechanisms regulated by TORC2.
  • To understand how Avo3p mutations impact TORC2 structure and effector recruitment.

Main Methods:

  • Utilized temperature-sensitive avo3 mutants to study TORC2 function.
  • Employed co-immunoprecipitation to analyze protein interactions and TORC2 complex composition.
  • Investigated phenotypic effects of gene deletions in Rho1p-GTPase-activating proteins.

Main Results:

  • Identified two distinct TORC2 signaling pathways, one mediated by Avo1p and another by Avo2p/Slm1p, based on suppressor mutations.
  • Demonstrated that Avo3p acts as a structural and signaling scaffold, essential for TORC2 integrity and effector recruitment.
  • Showed that both TORC2 signaling branches converge on Rho1p activation, with Avo2p/Slm1p signaling specifically linking to Rho1p via Tus1p.

Conclusions:

  • Avo3p is indispensable for maintaining TORC2 structure and facilitating its signaling.
  • TORC2 utilizes at least two distinct downstream pathways to regulate cellular processes.
  • These pathways converge on Rho1p, highlighting its central role in TORC2-mediated cellular regulation.

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