Regulation of the Caenorhabditis elegans gut cysteine protease gene cpr-1: requirement for GATA motifs

Abstract

Expression of the Caenorhabditis elegans cysteine protease gene cpr-1 is regulated both spatially and temporally. In situ hybridisation and Northern blot analysis have shown that this gene is expressed exclusively in gut cells of all developmental stages except the embryo. We now show by transgenic transformation with cpr-1/lac Z reporter gene constructs that a sequence contained within the cpr-1 5' flanking region can direct this spatial and temporal expression. Deletion analysis of the cpr-1 promoter indicates that as little as 212 bp of upstream sequence is sufficient for this expression, although more upstream sequence may be involved in quantitative regulation of expression. Mutation of two GATA-like sequence elements at positions -51 and -147 upstream of the transcription start site ablates all expression, indicating an essential role in cpr-1 regulation. A concatemer of the cpr-1 -147 GATA motif placed upstream of minimal promoter/lac Z reporter gene constructs results in strong reporter gene expression in gut cells of larval stages and also in embryos. Weak expression is also detected in hypodermal cells. This pattern is reversed in the adult stage with strong expression in hypodermal cells and weaker expression in gut cells. Our findings suggest that spatial and temporal regulation of the cpr-1 gene is complex and involves activation by a GATA-like transcription factor.