Sed1p and Srl1p are required to compensate for cell wall instability in Saccharomyces cerevisiae mutants defective in multiple GPI-anchored mannoproteins.
The covalently linked cell wall protein Ccw12p of Saccharomyces cerevisiae is a GPI-anchored protein (V. Mrsa et al., 1999, J Bacteriol 181: 3076-3086). Although only 121 amino acids long, the haemagglutinin-tagged protein released by laminarinase from the cell wall possesses an apparent molecular mass of > 300 kDa. A membrane-bound form with an apparent molecular mass of 58 kDa is highly O- and N-glycosylated and contains the GPI anchor. With a half-life of 2 min, the membrane form is transformed to the > 300 kDa form. The deletion mutant ccw12Delta grows slower than the wild type, is highly sensitive to Calcofluor white and contains 2.5 times more chitin. Further, compared with wild-type yeast, significantly more proteins are released from intact cells when treated with dithiothreitol. Interestingly, these defects become less pronounced when further GPI-anchored cell wall proteins are deleted. Mutant DeltaGPI (simultaneous deletion of CCW12, CCW13/DAN1, CCW14, TIP1 and CWP1) is similar in many respects to wild-type yeast. To find out how the cell wall is stabilized in mutant DeltaGPI, a genome-wide transcription analysis was performed. Of 159 significantly regulated genes, 14 encode either known or suspected cell wall-associated proteins. Analysis of genes affected in transcription revealed that SED1 and SRL1 in particular are required to reconstruct cell wall stability in the absence of multiple GPI-anchored mannoproteins.
Hagen
Ilja
I
Lehrstuhl für Zellbiologie und Pflanzenphysiologie, Universität Regensburg, Universitätsstrasse 31, 93053 Regensburg, Germany.
Ecker
Margit
M
Lagorce
Arnaud
A
Francois
Jean M
JM
Sestak
Sergej
S
Rachel
Reinhard
R
Grossmann
Guido
G
Hauser
Nicole C
NC
Hoheisel
Jörg D
JD
Tanner
Widmar
W
Strahl
Sabine
S
D002473:Cell Wall / Q000737:chemistry / Q000378:metabolism* / Q000648:ultrastructure; D002686:Chitin / Q000737:chemistry; D020869:Gene Expression Profiling; D015966:Gene Expression Regulation, Fungal; D017261:Glycosylphosphatidylinositols / Q000378:metabolism*; D008562:Membrane Glycoproteins / Q000235:genetics / Q000378:metabolism*; D009154:Mutation; D020411:Oligonucleotide Array Sequence Analysis; D010641:Phenotype; D011499:Protein Processing, Post-Translational; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism* / Q000648:ultrastructure; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism*; D014158:Transcription, Genetic
D017261:Glycosylphosphatidylinositols; D008562:Membrane Glycoproteins; C077394:SED1 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; C025363:mannoproteins; D002686:Chitin