Analysis of human cellular retinol-binding protein II promoter during enterocyte differentiation.
Cellular retinol binding protein II (CRBP II) is a vitamin A-binding protein that is expressed specifically in small intestinal villus absorptive cells. Previous studies have shown that retinoic acid upregulates endogenous human CRBP II gene expression in differentiated Caco-2 cells. To better characterize the regulation of human CRBP II expression, we analyzed the ability of receptor-selective agonists to enhance transcription from the 5'-upstream flanking region of the human CRBP II gene. Stable transfection experiments showed that the proximal 2.8-kb region of the human CRBP II gene is sufficient for retinoic acid inducibility in differentiated Caco-2 cells. However, direct sequence analysis and transient transfection experiments indicate that, unlike the rat CRBP II promoter, the human CRBP II promoter is not a direct retinoid X receptor target. The results indicate that the retinoic acid responsiveness of the human CRBP II promoter is mediated by an indirect mechanism and that this mechanism is associated with enterocyte differentiation.
Zhang
Liang
L
Department of Medicine, Washington University-St. Louis School of Medicine, St. Louis, Missouri 63110, USA.
E
Xueping
X
Luker
Kathryn E
KE
Shao
Jian-Su
JS
Levin
Marc S
MS
Suh
Eunran
E
Li
Ellen
E
D024506:5' Flanking Region / Q000235:genetics; D000077556:Alitretinoin; D000818:Animals; D000970:Antineoplastic Agents / Q000494:pharmacology; D001483:Base Sequence; D019556:COS Cells; D018938:Caco-2 Cells; D002454:Cell Differentiation / Q000502:physiology; D020895:Enterocytes / Q000166:cytology* / Q000502:physiology*; D005786:Gene Expression Regulation / Q000187:drug effects / Q000502:physiology; D006801:Humans; D051379:Mice; D008969:Molecular Sequence Data; D011401:Promoter Regions, Genetic / Q000235:genetics*; D051381:Rats; D018168:Receptors, Retinoic Acid / Q000819:agonists; D020218:Response Elements / Q000235:genetics; D047488:Retinoid X Receptors; D012177:Retinol-Binding Proteins / Q000235:genetics* / Q000378:metabolism; D054840:Retinol-Binding Proteins, Cellular; D014157:Transcription Factors / Q000819:agonists; D014162:Transfection; D014212:Tretinoin / Q000494:pharmacology; D014801:Vitamin A / Q000378:metabolism
D000970:Antineoplastic Agents; C518459:RBP2 protein, human; C518460:Rbp2 protein, mouse; C518461:Rbp2 protein, rat; D018168:Receptors, Retinoic Acid; D047488:Retinoid X Receptors; D012177:Retinol-Binding Proteins; D054840:Retinol-Binding Proteins, Cellular; D014157:Transcription Factors; D014801:Vitamin A; D000077556:Alitretinoin; D014212:Tretinoin