The cis‐element CE‐LPH1 of the rat intestinal lactase gene promoter interacts in vitro with several nuclear factors present in endodermal tissues

Abstract

We have shown by electrophoretic mobility shift assays that the nucleotide sequence CE-LPHl, centred at position -49 with respect to the transcription start site of the rat gene encoding intestinal lactase-phlorizin hydrolase, interacts in vitro with nuclear proteins present in the jejunum of suckling animals. Proteins binding to this element were also found in organs of endodennal origin that do not (or no longer) express lactase-phlorizin hydrolase, i.e. the colon, lung and the liver, but not in the brain. However, a DNA-protein interaction was hardly detected with nuclear extracts prepared from adult tissues, although typical factors binding to the Spl binding site were detected at the adult stage as in the sucklings. Southwestern blotting experiments conducted with nuclear extracts prepared from the tissues of suckling rats indicated that CE-LPHl interacts with several factors in the jejunum, colon, lung and the liver. Some of these DNA-binding proteins are specifically expressed in the jejunum or in the liver, whereas others seem to be shared with the colon and the lung. Hence, the c&element CE-LPHl located in close vicinity to the pseudo-TATA-box of the intestinal lactase-phlorizin hydrolase gene promoter interacts in vitro with a family of nuclear proteins which may represent markers of the endodermal lineage predominantly expressed prior to weaning.

The Specific Expression Patterns of Lactase, Sucrase and Calbindin-D9k in Weaning Rats Are Regulated at the Transcriptional Level

“…However after day 27, probably because of malnutrition, the L group could not maintain the same growth rate as the W group, so we terminated the experiment at this time. (23,24). This protein was important in identifying the tissue specificity of LPH and its specific expression during development (25).…”

Transcriptional control of the murine polymeric IgA receptor promoter by glucocorticoids

“…Gluco- corticoids have been proposed as a regulator of an intrinsic clock that controls in the expression pattern of several developmentally expressed genes in the intestine. Despite recent progress in the isolation and characterization of several such genes, including lactase and sucrase-isomaltase, investigators have yet to describe the presence of a classic glucocorticoid cisacting element or an indirect trans-element that controls their expression (3,43).…”

Regulation of lactase–phlorizin hydrolase gene expression by the caudal-related homoeodomain protein Cdx-2

“…Furthermore NF-LPH1 DNA-binding activity was only found in extracts of intestinal origin and was found to bind to a TTTAC-containing sequence. NF-LPH1-binding activity has been found to be high in newborn pigs [20] and rats [21], but relatively low in adult animals. The functional importance of this observation with regard to adult-type hypolactasia remains, however, to be established.…”