Gene Ontology annotation through association of InterPro records with GO terms
Gene Ontology annotation based on Enzyme Commission mapping
Annotation inferences using phylogenetic trees
Gene Ontology annotation based on UniProtKB/Swiss-Prot Subcellular Location vocabulary mapping, accompanied by conservative changes to GO terms applied by UniProt
Electronic Gene Ontology annotations created by ARBA machine learning models
A novel family of cell wall-related proteins regulated differently during the yeast life cycle.
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CRH1 and CRH2 encode a novel family of cell wall proteins with homology to beta-glucanases. Deletion causes Congo Red sensitivity. CRH1-GFP localizes to incipient bud site, septum, and ascospore envelopes.
"Crh1-green fluorescent protein was found at the incipient bud site, around the septum area in later stages of budding, and in ascospore envelopes...the alkali-soluble glucan fraction in the crh1Delta crh2Delta strain was almost twice the level in the wild-type"
Comprehensive proteomic analysis of Saccharomyces cerevisiae cell walls: identification of proteins covalently attached via glycosylphosphatidylinositol remnants or mild alkali-sensitive linkages.
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CRH1 identified as a GPI-modified cell wall protein by mass spectrometry of isolated cell walls.
"The identified proteins include 12 predicted glycosylphosphatidylinositol-modified CWPs ...seven of the identified proteins (Gas1p, Gas3p, Gas5p, Crh1p, Utr2p, Scw4p, and Scw10p) are classified as glycoside hydrolases"
Crh1p and Crh2p are required for the cross-linking of chitin to beta(1-6)glucan in the Saccharomyces cerevisiae cell wall.
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CRH1 and CRH2 are required for chitin-beta(1-6)glucan cross-links. Double mutant completely lacks these cross-links. Heat stress increases cross-linking and CRH1 expression via cell integrity pathway.
"chitin linked to beta(1-6)glucan is diminished in mutants of the CRH1 or the CRH2/UTR2 gene and completely absent in a double mutant...Crh1p and Crh2p are the first proteins directly implicated in the formation of cross-links between cell wall components in fungi"
Assembly of the yeast cell wall. Crh1p and Crh2p act as transglycosylases in vivo and in vitro.
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CRH1 and CRH2 act as transglycosylases in vivo and in vitro, transferring chitin chains to beta(1-6)glucan. High activity at bud scars. Demonstrated using fluorescent acceptors in intact cells, permeabilized cells, and isolated cell walls.
"the Crh proteins act by transferring chitin chains to beta(1-6)glucan, with a newly observed high activity in the bud scar. The importance of transglycosylation for cell wall assembly is thus firmly established"
Two novel techniques for determination of polysaccharide cross-links show that Crh1p and Crh2p attach chitin to both beta(1-6)- and beta(1-3)glucan in the Saccharomyces cerevisiae cell wall.
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CRH1 and CRH2 catalyze transfer of chitin to both beta(1-3)- and beta(1-6)-glucan. All chitin in crh1/crh2 double mutant is free (unlinked). Previous apparent residual beta(1-3)glucan-linked chitin was an artifact of chitinase contamination in zymolyase.
"Crh1p and Crh2p catalyze the transfer of chitin to both beta(1-3)- and beta(1-6)glucan, and the biosynthetic mechanism for all chitin cross-links in the cell wall has been established"
A novel fluorescence assay and catalytic properties of Crh1 and Crh2 yeast cell wall transglycosylases.
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Heterologously expressed CRH1 and CRH2 act as chitin transglycosylases. Both also have weak endochitinase activity. pH optimum 3.5, temperature optimum 37C. Minimal acceptor requires 2 hexopyranose units.
"Both proteins act as chitin transglycosylases; they use soluble chitin derivatives, such as carboxymethyl chitin, glycol-chitin and/or N-acetyl chito-oligosaccharides of DP (degree of polymerization)≥5 as the oligoglycosyl donors...Both proteins exhibited a weak chitinolytic activity"
One library to make them all: streamlining the creation of yeast libraries via a SWAp-Tag strategy.
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High-throughput SWAp-Tag localization study that assigned CRH1 to cell periphery.
"we constructed and investigated a library of ∼1,800 strains carrying SWAT-GFP modules at the amino termini of endomembrane proteins"
Proteins involved in building, maintaining and remodeling of yeast cell walls.
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Review placing Crh-family transglycosidases among the enzymes whose concerted synthase, hydrolase, and transglycosidase activities provide both firmness and flexibility of the yeast cell wall.
"synthases, hydrolases and transglycosidases whose concerted activities provide"
Mechanisms of redundancy and specificity of the Aspergillus fumigatus Crh transglycosylases.
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Structural and biochemical study of the Aspergillus fumigatus Crh family (orthologous to yeast Crh1/Crh2) establishing that Crh enzymes function redundantly as transglycosylases that crosslink both chitin-glucan and chitin-chitin, and providing a structural basis for the acceptor promiscuity via an elongated donor binding cleft and short acceptor site.
"this family of enzymes functions redundantly as"
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The donor (-4 to -1) substrate is bound in an extended cleft while the acceptor (+1 to +2) site is short, and a "hydrolysis product assisted" mechanism favours transglycosylation over hydrolysis -- a mechanistic model relevant to yeast Crh1.
"elongated binding cleft for the donor (-4 to -1) substrate and a short acceptor"
Genomic, transcriptomic, and metabolic characterization of 2-Phenylethanol-resistant Saccharomyces cerevisiae obtained by evolutionary engineering.
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Evolutionary-engineering study of 2-phenylethanol-resistant S. cerevisiae in which a missense mutation in CRH1 (encoding a chitin transglycosylase implicated in cell wall remodeling) is proposed to contribute to increased resistance to the cell wall-degrading enzyme lyticase, implicating CRH1-dependent wall remodeling in stress tolerance.
"mutation in CRH1 that encodes a chitin transglycosylase implicated in cell wall"
Falcon (Edison) deep research report: Saccharomyces cerevisiae CRH1 (YGR189C; UniProt P53301).
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Genetic evidence that Crh1/Crh2 are required to form chitin-glucan covalent complexes: loss of either gene reduces chitin linked to beta(1->6)-glucan, the double mutant abolishes detectable chitin-beta(1->6)-glucan linkage, and CRH1 overexpression increases the complex.
"loss of **CRH1** or **CRH2** reduces chitin linked to **β(1→6)-glucan**, while the **crh1Δ crh2Δ** double mutant abolishes detectable chitin–β(1→6)-glucan linkage; overexpression of **CRH1** increases the chitin–β(1→6)-glucan complex"
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The conserved GH16-like catalytic motif DE(I/L)DXE is essential for function in vivo; catalytic-site substitution mutants fail to complement Congo red sensitivity.
"A catalytic-site mutant allele (Crh1 with substitutions at key acidic residues) fails to complement Congo red sensitivity, implying that the predicted catalytic residues are essential for function in vivo"
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CRH1 is connected to the cell wall integrity (CWI) MAPK pathway: a shift to 38C induces CRH1 expression via the cell integrity pathway, and this induction is lost in slt2Delta.
"shifting cells to **38°C** increases CRH1 expression via the **cell integrity pathway**, and this induction is abolished in an **slt2Δ** mutant, directly linking CRH1 to the CWI MAPK pathway"
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CRH1 is a covalently incorporated, laminarinase-releasable GPI-anchored cell wall protein enriched at polarized growth sites (bud emergence, mother-daughter neck, bud scars) and marking spore envelopes during sporulation.
"Crh1-GFP localization studies show enrichment at **polarized growth sites**—bud emergence, the **mother–daughter neck**, and bud scars—where chitin is enriched; Crh1 also appears at mating-related structures and marks **spore envelopes** during sporulation"