Author/Editor     Benčina, M; Panneman, H; Ruijter, GJ; Legiša, M; Visser, J
Title     Characterization and overexpression of the Aspergillus niger gene encoding the cAMP-dependent protein kinase catalytic subunit
Type     članek
Source     Microbiology
Vol. and No.     Letnik 143, št. 4
Publication year     1997
Volume     str. 1211-20
Language     eng
Abstract     The gene pkaC encoding the catalytic subunit of cAMP-dependent protein kinase has been isolated from the industrially important filamentous fungus Aspergillus niger. A probe for screening A. niger phage libraries was generated by a polymerase chain reaction using degenerate primers. cDNA and genomic DNA clones were isolated and sequenced. An open reading frame of 1440 bp, interrupted by three short introns, encodes a polypeptide of 480 amino acids with a calculated molecular mass of 53813 Da. The cAMP-dependent protein kinase catalytic subunit (PKA-C) from A. niger has a 126 amino acid extension at the N-terminus compared to the PKA-C of higher eukaryotes that-except for the first 15 amino acids, which are homologous to the Magnaporthe grisea PKA-C-shows no significant similarity to the N-terminal extension of PKA-C of other lower eukaryotes. The catalytic core of PKA-C of A. niger shows extensive homology with the PKA-C isolated from all other eukaryotes. Low-stringency hybridization did not reveal any other pkaC homologue in A. niger. The cloned pkaC was used for transformation of A. niger, leading to increased levels of pkaC mRNA and PKA-C activity. Transformants overexpressing pkaC were phenotypically different with respect to growth, showing a more compact colony morphology, accompanied by a more dense sporulation, especially on media containing trehalose and glycerol. A number of transformants also showed a strongly reduced or complete absence of sporulation. This phenotype was quickly lost upon propagation of the strains.
Descriptors     GENES, FUNGAL
CYCLIC AMP-DEPENDENT PROTEIN KINASES
ASPERGILLUS NIGER
TRANSFORMATION, GENETIC
TRANSCRIPTION, GENETIC
SPORES, FUNGAL
SPECIES SPECIFICITY
SEQUENCE HOMOLOGY, AMINO ACID
SEQUENCE ANALYSIS, DNA
RECOMBINANT PROTEINS
PHENOTYPE
MOLECULAR SEQUENCE DATA
GLYCOLYSIS
GENOMIC LIBRARY
DNA, COMPLEMENTARY
BASE SEQUENCE
AMINO ACID SEQUENCE