AT-rich upstream sequence elements regulate spore germination-specific expression of the Dictyostelium discoideum celA gene

Two members of a family of spore germination-specific cDNAs, ceiA and ceiB, are expressed coordinately, exclusively during spore germination. In the present study the regulatory sequence elements responsible for ceiA germination-specific expression have been identified. The very AT-rich 81 bp sequence between -664 and -584 upstream of the translation initiation site was required for proper temporal transcription of the ceiA gene. This sequence is comprised of two cis elements, each of which was active by itself in allowing ceiA expression. Electrophoretic mobility shift assays showed that a factors) in an extract prepared from germinating spores bound to the ceiA regulatory region. One of the three complexes formed was specific for the germinating spore extract The results are consistent with the notion that the factors) that binds to this regulatory region is involved in expression of ceiA.