Saccharomyces cerevisiae Afr1 protein is a protein phosphatase 1/Glc7-targeting subunit that regulates the septin cytoskeleton during mating.
Glc7, the type1 serine/threonine phosphatase in the yeast Saccharomyces cerevisiae, is targeted by auxiliary subunits to numerous locations in the cell, where it regulates a range of physiological pathways. We show here that the accumulation of Glc7 at mating projections requires Afr1, a protein required for the formation of normal projections. AFR1-null mutants fail to target Glc7 to projections, and an Afr1 variant specifically defective in binding to Glc7 [Afr1(V546A F548A)] forms aberrant projections. The septin filaments in mating projections of AFR1 mutants initiate normally but then rearrange asymmetrically as the projection develops, suggesting that the Afr1-Glc7 holoenzyme may regulate the maintenance of septin complexes during mating. These results demonstrate a previously unknown role for Afr1 in targeting Glc7 to mating projections and in regulating the septin architecture during mating.
Department of Biochemistry and Molecular Biology, 1501 Kings Highway, LSU Health Sciences Center, Shreveport LA 71130, USA.
Jennifer P
JP
Bharucha
Jennifer R
JR
Larson
James B
JB
Konopka
Kelly
K
Tatchell
D016764:Cell Polarity / Q000502:physiology; D003593:Cytoplasm / Q000201:enzymology / Q000235:genetics / Q000648:ultrastructure; D003599:Cytoskeleton / Q000201:enzymology* / Q000235:genetics / Q000648:ultrastructure; D008840:Microfilament Proteins / Q000235:genetics / Q000378:metabolism; D009154:Mutation / Q000235:genetics; D010749:Phosphoprotein Phosphatases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D011485:Protein Binding / Q000235:genetics; D054645:Protein Phosphatase 1; D021122:Protein Subunits / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D012098:Reproduction / Q000235:genetics*; D012441:Saccharomyces cerevisiae / Q000201:enzymology* / Q000235:genetics / Q000648:ultrastructure; D029701:Saccharomyces cerevisiae Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*
C083723:AFR1 protein, S cerevisiae; D008840:Microfilament Proteins; D021122:Protein Subunits; D029701:Saccharomyces cerevisiae Proteins; C092048:GLC7 protein, S cerevisiae; D010749:Phosphoprotein Phosphatases; D054645:Protein Phosphatase 1