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Title: Molecular cloning and analysis of the regulation of cys-14/sup +/, a structural gene of the sulfur regulatory circuit of Neurospora crassa

Journal Article · · Mol. Cell. Biol.; (United States)
DOI:https://doi.org/10.1128/MCB.8.4.1504· OSTI ID:6945045

The cys-14/sup +/ gene encodes sulfate permease II, which is primarily expressed in mycelia. cys-14/sup +/ is one of a set of sulfur-related structural genes under the control of cys-3/sup +/ and scon/sup +/, the regulatory genes of the sulfur control circuit. The authors cloned cys-14/sup +/ from a cosmid library of Neurospora crassa DNA. A restriction fragment length polymorphism analysis showed that this clone maps to the region of chromosome IV corresponding to the cys-14/sup +/ locus. Northern blot analyses were used to examine the regulated expression of the cys-14/sup +/ gene. In the wild type, a 3-kilobase cysc-14/sup +/ transcript was highly expressed under sulfur-derepressing conditions but completely absent during sulfur repression. A cys-3 mutant, which cannot synthesize any of the sulfur-controlled enzymes, including sulfate permease II, did not possess any cys-14/sup +/ transcript under wither condition. A cys-3 temperature-sensitive revertant completely lacked any cys-14/sup +/ mRNA at the conditional temperature but expressed the cys-14/sup +/ transcript upon derepression at the permissive temperature. Mutation of a second sulfur regulatory gene, scon/sup c/, causes the expression of sulfur-related enzymes in a constitutive fashion; the scon/sup c/ mutant showed a corresponding constitutive expression of cys-14/sup +/ mRNA, such that it was present even in cells subjected to sulfur repression conditions. These results show that the cys-14/sup +/ gene is regulated through the modulation of message content by the cys-3/sup +/ and scon/sup c/ control genes in response to the sulfur levels of the cells.

Research Organization:
The Ohio State Univ., Columbus, OH (US)
OSTI ID:
6945045
Journal Information:
Mol. Cell. Biol.; (United States), Vol. 8:4
Country of Publication:
United States
Language:
English