ISSN:
1617-4623
Keywords:
Laccase gene
;
Transcriptional activation
;
Cycloheximide
;
Cross-pathway control gene
;
Neurospora crassa
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Abstract Expression of the laccase gene (lacc) of Neurospora crassa is transcriptionally inducible by the protein synthesis inhibitor cycloheximide. A lni-1 mutation, conferring the laccase non-inducible phenotype, was found to be a cpc-1 allele. Northern blots probed with plasmid pLAI, which carries the lacc gene revealed that the cpc-1 mutation abolishes the induced transcription of the lacc gene, indicating requirement of the cpc-1 gene for transcriptional activation of the lacc gene. In Northern blots probed with plasmid pABI, which bears arg-2 a gene whose transcription is under the control of CPC1, the level of the arg-2 transcript was shown to increase several-fold in wild-type mycelia but remained low in cpc-1 mycelia, after treatment with cycloheximide. This suggests that inhibition of protein synthesis with cycloheximide, as well as amino acid limitation, elicits the CPC1-mediated cross-pathway control. Characterization of the lacc upstream region using a series of 5′-deletion plasmids led to the identification of a 170 bp DNA region required for the induced lacc expression. Sequence analysis of this DNA region demonstrated that it includes a 9 by sequence with dyad symmetry, ATGAATCAT which differs only by a central base pair from ATGA(C/G)TCAT the recognition sequence characteristic of CPC1 and GCN4 binding sites. Possible mechanisms by which CPC1 mediates transcriptional activation of the lacc gene are discussed.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00284203
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