PMID- 17135299
OWN - NLM
STAT- MEDLINE
DCOM- 20070607
LR  - 20211203
IS  - 0363-6143 (Print)
IS  - 0363-6143 (Linking)
VI  - 292
IP  - 4
DP  - 2007 Apr
TI  - Regulation of the human biotin transporter hSMVT promoter by KLF-4 and AP-2: 
      confirmation of promoter activity in vivo.
PG  - C1305-12
AB  - The mechanism of biotin uptake in human intestine has been well characterized and 
      involves the human sodium-dependent multivitamin transporter (hSMVT), yet little 
      is known about the molecular/transcriptional regulation of the system. Previous 
      investigations cloned the 5' regulatory region of the hSMVT gene and identified 
      the minimal promoter. To expand these investigations, we compared activity of the 
      hSMVT promoter in three human intestinal epithelial cell lines (NCM460, Caco-2, 
      and HuTu-80) and contrasted a renal epithelial cell line (HEK-293). We analyzed 
      the role of putative cis-elements in regulating promoter activity and confirmed 
      activity of the cloned hSMVT promoter in vivo. In vitro studies demonstrated that 
      all cell lines utilized the same minimal promoter region, and mutation of 
      specific cis-regulatory elements [Kruppel-like factor 4 (KLF-4) and activator 
      protein-2 (AP-2)] led to a decrease in promoter activity in all intestinal cell 
      types but not in renal cells. Using electrophoretic mobility shift assays, we 
      identified two specific DNA/protein complexes. Using oligonucleotide competition 
      and antibody supershift analysis, we determined that KLF-4 and AP-2 were involved 
      in forming the complexes. In HEK-293 cells, overexpressing KLF-4 increased the 
      endogenous hSMVT message levels threefold and activated a cotransfected hSMVT 
      promoter-reporter construct. In vivo studies using hSMVT promoter-luciferase 
      transgenic mice established physiological relevance and showed the pattern of 
      hSMVT promoter expression to be similar to endogenous mouse SMVT mRNA expression. 
      The results demonstrate, for the first time, the importance of KLF-4 and AP-2 in 
      regulating the activity of the hSMVT promoter in the intestine and provide direct 
      in vivo confirmation of hSMVT promoter activity.
FAU - Reidling, Jack C
AU  - Reidling JC
AD  - Veterans Affairs Medical Center, Long Beach, CA 90822, USA.
FAU - Said, Hamid M
AU  - Said HM
LA  - eng
GR  - DK-56061/DK/NIDDK NIH HHS/United States
GR  - DK-58057/DK/NIDDK NIH HHS/United States
GR  - DK-73032/DK/NIDDK NIH HHS/United States
PT  - Journal Article
PT  - Research Support, N.I.H., Extramural
PT  - Research Support, Non-U.S. Gov't
DEP - 20061129
PL  - United States
TA  - Am J Physiol Cell Physiol
JT  - American journal of physiology. Cell physiology
JID - 100901225
RN  - 0 (KLF4 protein, human)
RN  - 0 (Klf4 protein, mouse)
RN  - 0 (Kruppel-Like Factor 4)
RN  - 0 (Kruppel-Like Transcription Factors)
RN  - 0 (Symporters)
RN  - 0 (Transcription Factor AP-2)
RN  - 0 (biotin transporter)
RN  - 6SO6U10H04 (Biotin)
SB  - IM
MH  - Animals
MH  - Base Sequence
MH  - Biotin/*metabolism
MH  - Cell Line
MH  - Epithelial Cells/*metabolism
MH  - Gene Expression Regulation
MH  - Genes, Reporter
MH  - Humans
MH  - Intestinal Mucosa/cytology
MH  - Kidney/cytology
MH  - Kruppel-Like Factor 4
MH  - Kruppel-Like Transcription Factors/*metabolism
MH  - Mice
MH  - Mice, Transgenic
MH  - Molecular Sequence Data
MH  - Mutation
MH  - *Promoter Regions, Genetic
MH  - Regulatory Sequences, Nucleic Acid
MH  - Response Elements
MH  - Symporters/genetics/*physiology
MH  - Transcription Factor AP-2/*metabolism
EDAT- 2006/12/01 09:00
MHDA- 2007/06/08 09:00
CRDT- 2006/12/01 09:00
PHST- 2006/12/01 09:00 [pubmed]
PHST- 2007/06/08 09:00 [medline]
PHST- 2006/12/01 09:00 [entrez]
AID - 00360.2006 [pii]
AID - 10.1152/ajpcell.00360.2006 [doi]
PST - ppublish
SO  - Am J Physiol Cell Physiol. 2007 Apr;292(4):C1305-12. doi: 
      10.1152/ajpcell.00360.2006. Epub 2006 Nov 29.