A cis-acting region required for the regulated expression of grg-1, a neurospora glucose-repressible gene: Two regulatorysites (CRE and NRS) are required to repress grg-1 expression

Grg-1 is a Neurospora gene which was identified as being a highly expressed glucose-repressible gene. A cis-acting regulatory region required for the regulated expression of grg-1 has been characterized.The regulatory region is found between 440 and 500 nucleotides upstream of the first major grg-1 start of transcription site and contains two distinct cis-acting regulatory elements. The upstream element consistsof the sequence GTGACGTCAC, which is identical to thepreviously identified CRE (Cyclic AMP-Responsive Element). The second element is a newly defined cis-acting regulatory site. The element has the sequence TTGCTAGCAA and has been named NRS (Neurospora Repressor Site). DNA binding proteins can be shown to bind to both of these exacting regulatory elements. Experiments in which these sites were deleted demonstrate that both cis-acting regulatory elements are required to turn off the in vitro expression of the grg-1 gene underconditions of glucose sufficiency.