DNA sequences required for expression of a Dictyostelium actin gene.

A 2.8-kb fragment of 5' non-coding DNA from the Dictyostelium actin 15 gene has previously been shown to contain all of the cis-acting DNA sequence elements required for normal developmentally-regulated transcription of actin gene fusion RNAs when reintroduced into the genome by DNA-mediated transformation. Deletion analysis of this promoter fragment indicates that all of the necessary information is contained within a 270-bp fragment of actin 15 5' non-coding DNA. This fragment contains four short G/C-rich repeated sequences that are also found in other co-regulated Dictyostelium actin genes. A 12-bp consensus sequence, AAAAATGGGG/ATT, is present in the regions essential for expression of two different Dictyostelium actin genes, actin 6 and actin 15, but is absent from an actin gene showing a different temporal pattern of developmental regulation. Deletion analysis and DNase I footprinting implicate this sequence as a functional cis-acting element required for transcription of the actin 15 gene.