TY - JOUR
T1 - Regulation of two homodimer hexosaminidases in the mycoparasitic fungus Trichoderma asperellum by glucosamine
AU - Ramot, Ofir
AU - Viterbo, Ada
AU - Friesem, Dana
AU - Oppenheim, Amos
AU - Chet, Ilan
PY - 2004/4
Y1 - 2004/4
N2 - Trichoderma asperellum is a mycoparasitic fungus which is used as a biocontrol agent against plant pathogens. Its hydrolytic enzymes take part in its parasitic interaction, degrading the pathogen cell wall and thereby helping to control disease. One of those enzymes, β-N-acetyl-D-glucosaminidase (GlcNAcase), degrades chitin, which is a major component of the cell wall of many plant-pathogenic fungi. Two GlcNAcases of T. asperellum T203, designated EXC1Y and EXC2Y, were purified, their genes and their promoters were sequenced, and their regulation was studied. The enzymes share homology (59% identity) but are easily distinguished by PAGE assay. Biochemical characterization, Edman degradation, and mass spectrometry demonstrated that EXC1Y and EXC2Y are both active as homodimers. Both genes are up-regulated by glucosamine (GlcN), in contrast to two endochitinases of this fungus. GlcN induces the secretion of several proteins (including a β-glucosidase), among which EXC1Y is the most abundant. An exc2y knockout was constructed, to study the regulation of EXC1Y expression and secretion. The fungus has the ability to store a high amount of this enzyme in an active form and secrete it into the medium later.
AB - Trichoderma asperellum is a mycoparasitic fungus which is used as a biocontrol agent against plant pathogens. Its hydrolytic enzymes take part in its parasitic interaction, degrading the pathogen cell wall and thereby helping to control disease. One of those enzymes, β-N-acetyl-D-glucosaminidase (GlcNAcase), degrades chitin, which is a major component of the cell wall of many plant-pathogenic fungi. Two GlcNAcases of T. asperellum T203, designated EXC1Y and EXC2Y, were purified, their genes and their promoters were sequenced, and their regulation was studied. The enzymes share homology (59% identity) but are easily distinguished by PAGE assay. Biochemical characterization, Edman degradation, and mass spectrometry demonstrated that EXC1Y and EXC2Y are both active as homodimers. Both genes are up-regulated by glucosamine (GlcN), in contrast to two endochitinases of this fungus. GlcN induces the secretion of several proteins (including a β-glucosidase), among which EXC1Y is the most abundant. An exc2y knockout was constructed, to study the regulation of EXC1Y expression and secretion. The fungus has the ability to store a high amount of this enzyme in an active form and secrete it into the medium later.
KW - β-Glucosidae
KW - β-N-Acetylglucosaminidase
KW - Biocontrol
KW - Chitinase
KW - Promoter
KW - Secretion regulation
UR - http://www.scopus.com/inward/record.url?scp=2542420910&partnerID=8YFLogxK
U2 - 10.1007/s00294-003-0478-0
DO - 10.1007/s00294-003-0478-0
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C2 - 14685768
AN - SCOPUS:2542420910
SN - 0172-8083
VL - 45
SP - 205
EP - 213
JO - Current Genetics
JF - Current Genetics
IS - 4
ER -