Pir Proteins of Saccharomyces cerevisiae Are Attached to β-1,3-Glucan by a New Protein-Carbohydrate Linkage

A family of covalently linked cell wall proteins of Saccharomyces cerevisiae, called Pir proteins, are characterized by up to 10 conserved repeating units. Ccw5/Pir4p contains only one complete repeating sequence and its deletion caused a release of the protein into the medium. The exchange of each...

Full description

Saved in:
Bibliographic Details
Published in:The Journal of biological chemistry 2006-04, Vol.281 (17), p.11523-11529
Main Authors: Ecker, Margit, Deutzmann, Rainer, Lehle, Ludwig, Mrsa, Vladimir, Tanner, Widmar
Format: Article
Language:English
Subjects:
Amino Acid Sequence
beta-Glucans - chemistry
beta-Glucans - metabolism
Cell Wall - chemistry
Cell Wall - metabolism
Mass Spectrometry
Molecular Sequence Data
Mutagenesis, Site-Directed
Peptide Fragments - chemistry
Peptide Fragments - metabolism
Repetitive Sequences, Nucleic Acid
Saccharomyces cerevisiae
Saccharomyces cerevisiae - genetics
Saccharomyces cerevisiae - metabolism
Saccharomyces cerevisiae Proteins - genetics
Saccharomyces cerevisiae Proteins - metabolism
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:A family of covalently linked cell wall proteins of Saccharomyces cerevisiae, called Pir proteins, are characterized by up to 10 conserved repeating units. Ccw5/Pir4p contains only one complete repeating sequence and its deletion caused a release of the protein into the medium. The exchange of each of three glutamines (Gln69, Gln74, Gln76) as well as one aspartic acid (Asp72) within the repeating unit leads to a loss of the protein from the cell wall. Amino acid sequencing revealed that only Gln74 is modified. Release of the protein with mild alkali, changed Gln74 to to glutamic acid, suggesting that Gln74 is involved in the linkage. Analysis by mass spectrometry showed that 5 hexoses are attached to Gln/Glu74. Sugar analysis revealed glucose as the only constituent. It is suggested that Pir proteins form novel, alkali labile ester linkages between the γ-carboxyl group of glutamic acids, arising from specific glutamines, with hydroxyl groups of glucoses of β-1,3-glucan chains. This transglutaminase-type reaction could take place extracellularly and would energetically proceed on the account of amido group elimination.
ISSN:0021-9258
1083-351X
DOI:10.1074/jbc.M600314200