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.
Bharucha
Jennifer P
JP
Department of Biochemistry and Molecular Biology, 1501 Kings Highway, LSU Health Sciences Center, Shreveport LA 71130, USA.
Larson
Jennifer R
JR
Konopka
James B
JB
Tatchell
Kelly
K
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