title: Identification of an extracellular acid trehalase and its gene involved in fungal pathogenesis of Metarizium anisopliae.
abstract: Trehalose is the main sugar in the haemolymph of insects and is a key nutrient source for an insect pathogenic fungus. Secretion of trehalose-hydrolysing enzymes may be a prerequisite for successful exploitation of this resource by the pathogen. An acid trehalase [EC 3.2.1.28] was purified to homogeneity from a culture of a locust-specific pathogen, Metarhizium anisopliae, and its properties were characterized. The gene (ATM1) of this acid trehalase was also isolated. The pure enzyme can efficiently hydrolyze haemolymph trehalose into glucose in vitro. The new acid trehalase appearing in the haemolymph of Locusta migratoria infected with M. anisopliae had the same pI and substrate specificity as the purified fungal acid trehalase, and the concentration of trehalose in the haemolymph decreased sharply after infection. RT-PCR also revealed the ATM1 gene's expression in the haemolymph of the infected insects. Our results indicated that the acid trehalase may serve as an "energy scavenger" and deplete blood trehalose during fungal pathogenesis.
authors.affiliation: Genetic Engineering Research Center, Bioengineering College, Chongqing University, Chongqing, P.R. China 400030.
authors.forename: Hua
authors.initials: H
authors.lastname: Zhao
authors.forename: Anthony Keith
authors.initials: AK
authors.lastname: Charnley
authors.forename: Zhongkang
authors.initials: Z
authors.lastname: Wang
authors.forename: Youping
authors.initials: Y
authors.lastname: Yin
authors.forename: Zhenlun
authors.initials: Z
authors.lastname: Li
authors.forename: Yanling
authors.initials: Y
authors.lastname: Li
authors.forename: Yueqing
authors.initials: Y
authors.lastname: Cao
authors.forename: Guoxiong
authors.initials: G
authors.lastname: Peng
authors.forename: Yuxian
authors.initials: Y
authors.lastname: Xia
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D017931:DNA Primers; D004591:Electrophoresis, Polyacrylamide Gel; D045604:Extracellular Fluid / Q000201:enzymology*; D007525:Isoelectric Focusing; D048188:Locusta migratoria / Q000382:microbiology*; D052981:Metarhizium / Q000201:enzymology*; D008969:Molecular Sequence Data; D020133:Reverse Transcriptase Polymerase Chain Reaction; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D013379:Substrate Specificity; D014198:Trehalase / Q000235:genetics*
chemical_list: D017931:DNA Primers; D014198:Trehalase