Differential expression of human riboflavin transporters -1, -2, and -3 in polarized epithelia: A key role for hRFT-2 in intestinal riboflavin uptake

Veedamali S. Subramanian, Sandeep B. Subramanya, Laramie Rapp, Jonathan S. Marchant, Thomas Y. Ma, Hamid M. Said

Research output: Contribution to journalArticle

37 Citations (Scopus)

Abstract

Transport of riboflavin (RF) across both the brush border membrane (BBM) and basolateral membrane (BLM) of the polarized enterocyte occurs via specific carrier-mediated mechanisms. Although, three human riboflavin transporters (hRFTs), i.e., hRFT-1, hRFT-2 and hRFT-3 are expressed in the intestine, little is known about the cell surface domain(s) at which these specific hRFTs are expressed. Here, we used live cell confocal imaging of intestinal epithelial Caco-2 and renal MDCK cells to show that the hRFT-1 is mainly expressed at the BLM, hRFT-2 is exclusively expressed at the apical membrane, while hRFT-3 is mostly localized inside intracellular vesicular structures (with some expression at the BLM). Further the level of hRFT-2 mRNA expression in Caco-2 cells and in native human intestine is significantly higher than that of hRFT-1 and -3; hRFT-2 was also more efficient in transporting 3H-RF than hRFT-1 and -3. These findings implied an important role for hRFT-2 in intestinal RF uptake, a conclusion that was further supported by findings of hRFT-2 gene-specific siRNA knockdown investigation. These results show that members of the hRFT family are differentially expressed in polarized epithelia, and that the apically expressed hRFT-2 plays a key role in intestinal RF accumulation.

Original languageEnglish (US)
Pages (from-to)3016-3021
Number of pages6
JournalBiochimica et Biophysica Acta - Biomembranes
Volume1808
Issue number12
DOIs
StatePublished - Dec 1 2011

Fingerprint

Riboflavin
Epithelium
Membranes
Intestines
human SLC52A3 protein
Madin Darby Canine Kidney Cells
Caco-2 Cells
Enterocytes
Microvilli
Population Groups
Small Interfering RNA
Brushes
Kidney
Genes
Messenger RNA
human RFT3 protein
Imaging techniques

All Science Journal Classification (ASJC) codes

  • Biophysics
  • Biochemistry
  • Cell Biology

Cite this

Subramanian, Veedamali S. ; Subramanya, Sandeep B. ; Rapp, Laramie ; Marchant, Jonathan S. ; Ma, Thomas Y. ; Said, Hamid M. / Differential expression of human riboflavin transporters -1, -2, and -3 in polarized epithelia : A key role for hRFT-2 in intestinal riboflavin uptake. In: Biochimica et Biophysica Acta - Biomembranes. 2011 ; Vol. 1808, No. 12. pp. 3016-3021.
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abstract = "Transport of riboflavin (RF) across both the brush border membrane (BBM) and basolateral membrane (BLM) of the polarized enterocyte occurs via specific carrier-mediated mechanisms. Although, three human riboflavin transporters (hRFTs), i.e., hRFT-1, hRFT-2 and hRFT-3 are expressed in the intestine, little is known about the cell surface domain(s) at which these specific hRFTs are expressed. Here, we used live cell confocal imaging of intestinal epithelial Caco-2 and renal MDCK cells to show that the hRFT-1 is mainly expressed at the BLM, hRFT-2 is exclusively expressed at the apical membrane, while hRFT-3 is mostly localized inside intracellular vesicular structures (with some expression at the BLM). Further the level of hRFT-2 mRNA expression in Caco-2 cells and in native human intestine is significantly higher than that of hRFT-1 and -3; hRFT-2 was also more efficient in transporting 3H-RF than hRFT-1 and -3. These findings implied an important role for hRFT-2 in intestinal RF uptake, a conclusion that was further supported by findings of hRFT-2 gene-specific siRNA knockdown investigation. These results show that members of the hRFT family are differentially expressed in polarized epithelia, and that the apically expressed hRFT-2 plays a key role in intestinal RF accumulation.",
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Differential expression of human riboflavin transporters -1, -2, and -3 in polarized epithelia : A key role for hRFT-2 in intestinal riboflavin uptake. / Subramanian, Veedamali S.; Subramanya, Sandeep B.; Rapp, Laramie; Marchant, Jonathan S.; Ma, Thomas Y.; Said, Hamid M.

In: Biochimica et Biophysica Acta - Biomembranes, Vol. 1808, No. 12, 01.12.2011, p. 3016-3021.

Research output: Contribution to journalArticle

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T1 - Differential expression of human riboflavin transporters -1, -2, and -3 in polarized epithelia

T2 - A key role for hRFT-2 in intestinal riboflavin uptake

AU - Subramanian, Veedamali S.

AU - Subramanya, Sandeep B.

AU - Rapp, Laramie

AU - Marchant, Jonathan S.

AU - Ma, Thomas Y.

AU - Said, Hamid M.

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