Disease relevance of PGU1

• The sequence encoding the endopolygalacturonase (PG) of Fusarium moniliforme was cloned into the E. coli/yeast shuttle vector Yepsec1 for secretion in yeast [1].
• One of the two previously characterized genes coding for the abundant polygalacturonases I and II (PGI and PGII) found in a commercial pectinase preparation was used as a probe to isolate five more genes by screening a genomic DNA library in phage lambda EMBL4 using conditions of moderate stringency [2].

High impact information on PGU1

• One of the MAPK-regulated genes is PGU1, which encodes a secreted enzyme that hydrolyzes polygalacturonic acid, a structural barrier to microbial invasion present in the natural plant substrate of S. cerevisiae [3].
• A cis-acting sequence homologous to the yeast filamentation and invasion response element regulates expression of a pectinase gene from the bean pathogen Colletotrichum lindemuthianum [4].
• In the present study, promoter deletion and mutagenesis, as well as gel shift mobility assays, allowed for the first time identification of cis-acting elements that bind protein factors and are essential for the regulation of a pectinase gene [4].
• The signaling pathway(s) that control pectinase gene expression are currently unknown in filamentous fungi [4].
• Disruption of tpsA only weakly reduces growth on glucose, and neither influences the glucose induction of a low affinity glucose permease nor interferes with the catabolite repression of a pectinase; it causes reduced the heat tolerance of conidia. tpsB was cloned by a polymerase chain reaction-based strategy [5].

Biological context of PGU1

• After comparison of the current genes with their ancient (up to 35-40 million years) counterparts it was concluded that essential genes such as rRNA18S are highly conserved and that even normal 'house-keeping' genes, such as PGU1, are strikingly conserved along the millions of years that S. cerevisiae has evolved [6].
• The expression of PGU1 gene in several strains of S. cerevisiae revealed that the polygalacturonase activity depended on the plasmid used and also on the genetic background of each strain but in all cases the enzymatic activity increased [7].
• Mutation of the two potential glycosylation sites in PGU1 showed that the two residues individually (N318D, N330D) did not affect secreted enzyme activity, but the double mutant caused a 50% reduction in enzyme activity when compared to the wild-type PGU1 transformant [8].
• Analysis of the aa sequence indicated that the first 25 aa constitute a signal sequence and a motif (C218XGGHGXSIGSVG230) that is usually associated with a PG active site [9].
• Few differences were found between the two deduced amino acid sequences encoded by PGL1-1 from a pectolytic (PG+) strain (SCPP) and PGL1-2 from a non-pectolytic (PG-) strain (X2180-1B) [10].

Associations of PGU1 with chemical compounds

• A pectinolytic industrial yeast strain of Saccharomyces cerevisiae was generated containing the S. cerevisiae endopolygalacturonase gene (PGU1) constitutively expressed under the control of the 3-phosphoglycerate kinase gene (PGK1) promoter [11].
• Expression of PG proteins, engineered by site-directed mutagenesis, in P. pastoris showed that aspartic acid residues at positions 179, 200, and 201, and histidine 222 were essential for enzyme activity [8].
• Phenotypic analyses of the mutants revealed reduced pectinase activity and conidial adhesion to polystyrene [12].
• The interference of galacturonic acid or oligomers resulting from PG activity was completely eliminated [13].
• The most frequently used tests are the Nelson method using copper(II) and an arsenomolybdate reagent to detect PG activity, and the colorimetric method using thiobarbituric acid (TBA) to detect PL activity [13].

Other interactions of PGU1

• Working with insects taken from amber, it was possible to amplify the ATP9, PGU1 and rRNA18S ancient genes of Saccharomyces cerevisiae corresponding to samples from the Miocene and Oligocene [6].
• Cloning of the PGL1 open reading frame behind the ADH1 promoter allowed overexpression of polygalacturonase activity in S. cerevisiae [14].

Analytical, diagnostic and therapeutic context of PGU1

• The time needed for wine filtration was dramatically reduced in wines elaborated with the PGU1 recombinant strain, and was comparable to the filtration time shown by wines elaborated from must supplemented with fungal pectolytic enzymes [15].
• Cloning, sequence analysis and overexpression of a Saccharomyces cerevisiae endopolygalacturonase-encoding gene (PGL1) [10].
• The enzyme, named Pgl1P, had an apparent M(r) of 42 kDa as shown by SDS-PAGE [14].
• Immunoprecipitation demonstrates stable complex formation of Rad21 with Psm1 and Psm3 but not with Psc3 [16].
• The genetic determination of polygalacturonase (PG) production in Saccharomyces cerevisiae was studied by biochemical and classical genetic techniques [17].

References