Ptc1p regulates cortical ER inheritance via Slt2p.
Studies in the yeast Saccharomyces cerevisiae have shown that the inheritance of endoplasmic reticulum (ER), mitochondria, and vacuoles involves the capture of a tubular structure at the bud tip. Ptc1p, a serine/threonine phosphatase, has previously been shown to regulate mitochondrial inheritance by an unknown mechanism. Ptc1p regulates the high osmolarity glycerol mitogen-activated protein kinase (MAPK) pathway and has also been implicated in the cell wall integrity (CWI) MAPK pathway. Here we show that the loss of Ptc1p or the Ptc1p binding protein, Nbp2p, causes a prominent delay in the delivery of ER tubules to the periphery of daughter cells and results in a dramatic increase in the level of phosphorylated Slt2p, the MAPK in the CWI pathway. Either loss of Slt2p or inhibition of the CWI pathway by addition of sorbitol, suppresses the ER inheritance defect in the ptc1Delta and nbp2Delta mutants. Our findings indicate that Ptc1p and Nbp2p regulate ER inheritance through the CWI MAPK pathway by modulating the MAPK, Slt2p.
Du
Yunrui
Y
Howard Hughes Medical Institute, Yale University School of Medicine, New Haven, CT, USA.
Walker
Lee
L
Novick
Peter
P
Ferro-Novick
Susan
S
D048868:Adaptor Proteins, Signal Transducing; D002352:Carrier Proteins / Q000378:metabolism; D004721:Endoplasmic Reticulum / Q000378:metabolism*; D017353:Gene Deletion; D005800:Genes, Fungal / Q000235:genetics; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism*; D010749:Phosphoprotein Phosphatases / Q000172:deficiency / Q000378:metabolism*; D010766:Phosphorylation; D054648:Protein Phosphatase 2; D012441:Saccharomyces cerevisiae / Q000166:cytology / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000378:metabolism*
D048868:Adaptor Proteins, Signal Transducing; D002352:Carrier Proteins; C487575:NBP2 protein, S cerevisiae; C103130:SEC3 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; C088589:HOG1 protein, S cerevisiae; D020928:Mitogen-Activated Protein Kinases; C072724:SLT2 protein, S cerevisiae; C087358:PTC1 protein, S cerevisiae; D010749:Phosphoprotein Phosphatases; D054648:Protein Phosphatase 2