ABSTRACT
A full-length cDNA coding for a putative adenosine deaminase (Fv-ada) was isolated from the basidiomycete Flammulina velutipes. Fv-ada encodes a polypeptide consisting of 537 amino acid residues, which has a consensus sequence conserved among adenosine deaminase-related growth factors (ADGF) found in several metazoa, including chordates and insects. Fv-ada transcript was detected at all stages of growth in dikaryotic F. velutipes cells, with a peak at the primordial stage. Heterologous expression of Fv-ada in the yeast Pichia pastoris produced recombinant Fv-ADA that catalyzed the conversion of adenosine to inosine. Dikaryotic mycelia from F. velutipes were transformed with the binary plasmid pFungiway-Fv-ada, which was designed to suppress the expression of Fv-ada through RNA interference. The growth rates of the resulting transformants were retarded in response to the degree of suppression, indicating that Fv-ada plays an important role in the mycelial growth of F. velutipes. These results suggested that ADGF could function as growth factors in fungi, as is seen in other eukaryotes.
Subject(s)
Adenosine Deaminase/genetics , Flammulina/genetics , Intercellular Signaling Peptides and Proteins/genetics , Adenosine Deaminase/metabolism , Adenosine Deaminase/physiology , Amino Acid Sequence , Flammulina/enzymology , Flammulina/growth & development , Intercellular Signaling Peptides and Proteins/metabolism , Intercellular Signaling Peptides and Proteins/physiology , Molecular Sequence Data , Mycelium/growth & development , Pichia/genetics , Pichia/metabolism , RNA Interference , Sequence Homology, Amino AcidABSTRACT
Agrobacterium tumefaciens was used to transform the vegetative dikaryotic mycelium of Flammulina velutipes using a hygromycin B resistance gene as selectable marker. The gene coding for urogen III methyltransferase (cob) was introduced into F. velutipes dikaryotic cells. The resulting transformant cells generated a bright red fluorescence, indicating that cob is promising as a reporter gene in F. velutipes.