BACKGROUND & AIMS: The importance of messenger RNA (mRNA) localization in human enterocytes is poorly understood. Previous studies from our laboratory have indicated that mRNAs are asymmetrically distributed in human intestinal epithelial cells, but in general colocalized with their encoded proteins. The aim of this study was to characterize, in human enterocytes, mRNA localization patterns of three genes with distinctly different functions. METHODS: mRNA distribution was determined by in situ hybridization with digoxigenin-labeled RNA probes in tissue sections of human jejunum. RESULTS: The mRNA for villin, a well-characterized microvillus cytoskeletal protein, was sorted to the basal region of the enterocyte. The mRNA for human sodium glucose cotransporter 1 was localized to the apical region, and the mRNA for human liver fatty acid-binding protein was distributed diffusely in the cytoplasm. CONCLUSIONS: The three distinct mRNA distribution patterns suggest that active mRNA sorting mechanisms exist in human enterocytes. This study also reveals for the first time that dichotomies may occur between the distribution patterns of sorted mRNAs and their encoded proteins.
BACKGROUND & AIMS: The importance of messenger RNA (mRNA) localization in human enterocytes is poorly understood. Previous studies from our laboratory have indicated that mRNAs are asymmetrically distributed in human intestinal epithelial cells, but in general colocalized with their encoded proteins. The aim of this study was to characterize, in human enterocytes, mRNA localization patterns of three genes with distinctly different functions. METHODS: mRNA distribution was determined by in situ hybridization with digoxigenin-labeled RNA probes in tissue sections of human jejunum. RESULTS: The mRNA for villin, a well-characterized microvillus cytoskeletal protein, was sorted to the basal region of the enterocyte. The mRNA for humansodium glucose cotransporter 1 was localized to the apical region, and the mRNA for human liver fatty acid-binding protein was distributed diffusely in the cytoplasm. CONCLUSIONS: The three distinct mRNA distribution patterns suggest that active mRNA sorting mechanisms exist in human enterocytes. This study also reveals for the first time that dichotomies may occur between the distribution patterns of sorted mRNAs and their encoded proteins.