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PDZ‐containing protein PDZD11 is associated with the human sodium‐dependent multivitamin transporter, hSMVT in intestinal epithelial cells
Author(s) -
Nabokina Svetlana M.,
Subramanian Veedamali S.,
Said Hamid M.
Publication year - 2011
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.25.1_supplement.657.1
Absorption of biotin in intestine is mediated through the sodium‐dependent multivitamin transporter (SMVT). There is nothing currently known about protein(s) that interacts with the SMVT system in intestinal epithelial cells and the physiological/cell biological consequences of such interactions. In this study, we used a yeast two‐hybrid approach and identified a PDZ‐containing protein PDZD11 as a binding protein for the human SMVT (hSMVT). Existence of interaction between hSMVT and PDZD11 was confirmed by GST‐pull‐down assay, mammalian two‐hybrid assay and co‐immunoprecipitation assay. Confocal imaging of live human intestinal epithelial HuTu‐80 expressing hSMVT‐GFP and DsRed‐PDZD11 demonstrated co‐localization of these two proteins. Co‐expression of PDZD11 with hSMVT led to a significant induction in [ 3 H]biotin uptake. On the other hand, PDZD11 knockdown with gene‐specific siRNA led to a significant decrease in biotin uptake and was associated with a significant decrease in the hSMVT plasma membrane level as was shown by biotinylation assay. Using truncation approach we also demonstrated the requirement of the PDZ binding domain of hSMVT in interaction with PDZD11. These findings demonstrate for the first time the identification of PDZD11 as a binding partner for the hSMVT and that this interaction affects hSMVT function and cell biology. (Supported by grants from DVA and NIH).