CHARACTERIZATION OF A SILENCER THAT MODULATES TRANSCRIPTION OF THE HUMAN DISTAL ALDOLASE A PROMOTER

Transcription from the distal promoter (pL) of the human aldolase A ge ne is driven by both positive and negative cis-acting elements. With f ootprinting and gel mobility assays we defined: (i) the position of th e negative regulatory cis-element (AldA-NRE), which spans a GA-rich se quence; (ii) the sequence of AldA-NRE, which is critical for protein s pecific binding and is homologous to other silencer-like motifs. Remov al of the negative cis-element fully restores the expression of the di stal promoter. Insertion of the AldA-NRE upstream from a heterologous promoter results in a 6-fold decrease in CAT reporter gene expression, suggesting that AldA-NRE might be involved in a more general type of mechanism that mediates repression of gene transcription. (C) 1995 Aca demic Press, Inc.