The filamentous fungus Aspergillus niger contains two "differentially regulated" trehalose-6-phosphate synthase-encoding genes, tpsA and tpsB.
Two genes encoding trehalose-6-phosphate synthase were cloned from Aspergillus niger. tpsA was cloned using the Saccharomyces cerevisiae GGS1/TPS1 gene as a probe. It encodes a 517-amino acid polypeptide with 64-70% similarity to trehalose-6-phosphate synthase of S. cerevisiae, Kluyveromyces lactis, and Schizosaccharomyces pombe. Its transcription occurs constitutively and is enhanced on carbon-derepressing carbon sources, coinciding with the presence of a CreA-binding nucleotide motif in the 5'-noncoding region of tpsA. 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. Its 480 amino acid sequence showed 76.5% identity to tpsA. Its transcription was hardly detectable at ambient temperatures but was enhanced strongly upon heat shock, which agrees with the presence of several copies of a C4T stress-responsive element in its 5'-upstream sequences. Hence the function of yeast GGS1/TPS1 has been split into two differentially regulated genes in A. niger, of which none appears to be involved in glucose sensing.
Wolschek
M F
MF
Section of Microbial Biochemistry, Institute of Biochemical Technology and Microbiology, University of Technology of Vienna, Getreidemarkt 9/172-5, A-1060 Wien, Austria.
Kubicek
C P
CP
D000595:Amino Acid Sequence; D001234:Aspergillus niger / Q000201:enzymology* / Q000235:genetics* / Q000254:growth & development; D001483:Base Sequence; D001665:Binding Sites; D003001:Cloning, Molecular; D017931:DNA Primers; D005656:Fungal Proteins / Q000378:metabolism; D005800:Genes, Fungal; D005947:Glucose / Q000378:metabolism; D005964:Glucosyltransferases / Q000096:biosynthesis* / Q000737:chemistry / Q000235:genetics*; D007716:Kluyveromyces / Q000201:enzymology; D008969:Molecular Sequence Data; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D011994:Recombinant Proteins / Q000096:biosynthesis; D012097:Repressor Proteins / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000235:genetics; D012568:Schizosaccharomyces / Q000201:enzymology; D017386:Sequence Homology, Amino Acid; D012689:Sequence Homology, Nucleic Acid; D014158:Transcription, Genetic
D017931:DNA Primers; D005656:Fungal Proteins; D011993:Recombinant Fusion Proteins; D011994:Recombinant Proteins; D012097:Repressor Proteins; C071237:CreA protein, Aspergillus nidulans; D005964:Glucosyltransferases; C023180:trehalose-6-phosphate synthase; D005947:Glucose