
-   SP1: The promoter of the human PGHS-1 gene lacks a TATA box, has a very GC-rich region, and contains multiple transcription start sites [PMID: 1536575]. Two elements have been identified that contribute to constitutive expression of PGHS-1 in human umbilical vein endothelial cells (HUVEC). The study demonstrated that Sp1 cis-regulatory elements in the human PGHS-1 promoter, at positions -111/-105 and -610/-604, bind the trans-activating Sp1 protein [PMID: 9054382]. Deletion of either site leads to a reduction of about 50% in basal transcription, and deletion of both sites results in a reduction of about 75% [PMID: 9054382].
-   Three putative AP-1 binding sites were found, two within the first exon and intron and another at position -2097 to -2090. The AP-1 site at position -2097 is adjacent to a sequence with similarity to a negative glucocorticoid regulatory element (nGRE) (position -2123 to -2009). The presence of AP sites by themselves, or in conjunction with an nGRE sequence, suggests a possible interplay between jun/fos regulatory proteins and the glucocorticoid receptor for positive and negative regulation of the PGH synthase gene [PMID: 1536575].
