Isocitrate lyase of Ashbya gossypii--transcriptional regulation and peroxisomal localization.
The isocitrate lyase-encoding gene AgICL1 from the filamentous hemiascomycete Ashbya gossypii was isolated by heterologous complementation of a Saccharomyces cerevisiae icl1d mutant. The open reading frame of 1680 bp encoded a protein of 560 amino acids with a calculated molecular weight of 62584. Disruption of the AgICL1 gene led to complete loss of AgIcl1p activity and inability to grow on oleic acid as sole carbon source. Compartmentation of AgIcl1p in peroxisomes was demonstrated both by Percoll density gradient centrifugation and by immunogold labeling of ultrathin sections using specific antibodies. This fitted with the peroxisomal targeting signal AKL predicted from the C-terminal DNA sequence. Northern blot analysis with mycelium grown on different carbon sources as well as AgICL1 promoter replacement with the constitutive AgTEF promoter revealed a regulation at the transcriptional level. AgICL1 was subject to glucose repression, derepressed by glycerol, partially induced by the C2 compounds ethanol and acetate, and fully induced by soybean oil.
Institut für Biotechnologie 1, Forschungszentrum Jülich GmbH, Germany.
I
I
Maeting
G
G
Schmidt
H
H
Sahm
J L
JL
Revuelta
Y D
YD
Stierhof
K P
KP
Stahmann
D000085:Acetates / Q000378:metabolism / Q000494:pharmacology; D000595:Amino Acid Sequence; D002499:Centrifugation, Density Gradient; D003001:Cloning, Molecular; D000431:Ethanol / Q000378:metabolism / Q000494:pharmacology; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects; D005816:Genetic Complementation Test; D005947:Glucose / Q000378:metabolism / Q000494:pharmacology; D005990:Glycerol / Q000378:metabolism / Q000494:pharmacology; D007522:Isocitrate Lyase / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D008830:Microbodies / Q000201:enzymology* / Q000648:ultrastructure; D016253:Microscopy, Immunoelectron; D008969:Molecular Sequence Data; D008970:Molecular Weight; D016254:Mutagenesis, Insertional / Q000235:genetics; D011401:Promoter Regions, Genetic / Q000235:genetics; D012333:RNA, Messenger / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000201:enzymology / Q000235:genetics; D004718:Saccharomycetales / Q000201:enzymology* / Q000378:metabolism / Q000648:ultrastructure; D016415:Sequence Alignment; D013024:Soybean Oil / Q000378:metabolism / Q000494:pharmacology
D000085:Acetates; D012333:RNA, Messenger; D000431:Ethanol; D013024:Soybean Oil; D007522:Isocitrate Lyase; D005947:Glucose; D005990:Glycerol