The two isozymes of rat intestinal alkaline phosphatase are products of two distinct genes

Q. Xie, D. H. Alpers

Research output: Contribution to journalArticlepeer-review

26 Scopus citations

Abstract

Rat intestinal alkaline phosphatases (IAP-I and -II) differ in primary structure, substrate specificity, tissue localization, and response to fat feeding. This study identifies two distinct genes (∼5-6 kb) corresponding to each isozyme and containing 11 exons of nearly identical size. The exon-intron junctions are identical with those found in IAP genes from other species. The 1.7 and 1.2 bp of 5′ flanking regions isolated from each gene, respectively, contain Sp1 and gut-enriched Kruppel-like factor (GKLF) binding sites, but otherwise show little identity. There is a potential CAAT-box 14 bp 5′ to the transcriptional start site, 36 bp upstream from IAP-I, and a TATA-box 31 bp 5′ to the transcriptional start site, 55 bp upstream from IAP-II. Transfection of these promoter regions (linked to luciferase as a reporter gene) into a kidney cell line, COS-7, produced the differential response to oleic acid expected from in vivo studies, i.e., threefold increase using the 5′ flanking region of IAP-II, but not IAP-I. This response was not reproduced by 5,8,11,14-eicosatetraynoic acid (ETYA) or clofibrate, suggesting that peroxisome proliferator response elements are not involved. Isolation of the IAP-II gene will allow determination of the sequences responsible for dietary fat response in the enterocyte.

Original languageEnglish
Pages (from-to)1-8
Number of pages8
JournalPhysiological genomics
Volume2000
Issue number3
DOIs
StatePublished - Sep 2000

Keywords

  • Oleic acid response
  • Promoter regions

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