Diurnal Expression and Function of Peptide Transporter 1 (PEPT1)1

Hisham G. Qandeel; Judith A. Duenes; Ye Zheng; Michael G. Sarr

doi:10.1016/j.jss.2009.03.052

Diurnal Expression and Function of Peptide Transporter 1 (PEPT1)¹

Hisham G. Qandeel, Judith A. Duenes, Ye Zheng, Michael G. Sarr

Gastroenterologic and General Surgery

Research output: Contribution to journal › Article › peer-review

18 Scopus citations

Abstract

Background: Protein is absorbed primarily as di/tripeptides, which are transported into the enterocyte exclusively by H⁺/peptide cotransporter 1 (PEPT1). Diurnal changes in expression and function of several other mucosal transporters occur in rat. Diurnal variations in mRNA, protein, and transport function of PEPT1 occur in rat duodenum and jejunum, but not in ileum. Methods: Mucosal levels of mRNA and protein were determined at 9 AM, 3 PM, 9 PM, and 3 AM (n = 6 each) by real time RT-PCR and Western blotting, respectively, in rats maintained in a 12-h light/dark room [light 6 AM to 6 PM]; transporter-mediated uptake of dipeptide (Gly-Sar) was also measured by everted sleeve technique. Results: mRNA transcripts of PEPT1 and Gly-Sar uptake varied diurnally in duodenum and jejunum (peak at 3 PM, P < 0.05), but not in ileum; maximal uptake was in jejunum. V_max (nmol/cm/min) was greater at 3 PM and 9 PM compared with 9 AM (3 PM versus 9 AM: 104 versus 62 in duodenum, and 185 versus 101 in jejunum; P < 0.03); K_m was unchanged across time points or locations. Protein levels varied minimally in jejunum and ileum with peaks at 9 PM and 3 AM. Conclusion: Gene expression and transport function of PEPT1 vary diurnally in duodenum and jejunum in temporal association with nocturnal feeding of rats.

Original language	English (US)
Pages (from-to)	123-128
Number of pages	6
Journal	Journal of Surgical Research
Volume	156
Issue number	1
DOIs	https://doi.org/10.1016/j.jss.2009.03.052
State	Published - Sep 2009

Keywords

PEPT1
diurnal rhythm
peptide transporter 1
protein absorption
rat
short peptides
small intestine

ASJC Scopus subject areas

Surgery

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10.1016/j.jss.2009.03.052

Cite this

@article{c89943baa81a4ea5a25c7b57a0129c12,

title = "Diurnal Expression and Function of Peptide Transporter 1 (PEPT1)1",

abstract = "Background: Protein is absorbed primarily as di/tripeptides, which are transported into the enterocyte exclusively by H+/peptide cotransporter 1 (PEPT1). Diurnal changes in expression and function of several other mucosal transporters occur in rat. Diurnal variations in mRNA, protein, and transport function of PEPT1 occur in rat duodenum and jejunum, but not in ileum. Methods: Mucosal levels of mRNA and protein were determined at 9 AM, 3 PM, 9 PM, and 3 AM (n = 6 each) by real time RT-PCR and Western blotting, respectively, in rats maintained in a 12-h light/dark room [light 6 AM to 6 PM]; transporter-mediated uptake of dipeptide (Gly-Sar) was also measured by everted sleeve technique. Results: mRNA transcripts of PEPT1 and Gly-Sar uptake varied diurnally in duodenum and jejunum (peak at 3 PM, P < 0.05), but not in ileum; maximal uptake was in jejunum. Vmax (nmol/cm/min) was greater at 3 PM and 9 PM compared with 9 AM (3 PM versus 9 AM: 104 versus 62 in duodenum, and 185 versus 101 in jejunum; P < 0.03); Km was unchanged across time points or locations. Protein levels varied minimally in jejunum and ileum with peaks at 9 PM and 3 AM. Conclusion: Gene expression and transport function of PEPT1 vary diurnally in duodenum and jejunum in temporal association with nocturnal feeding of rats.",

keywords = "PEPT1, diurnal rhythm, peptide transporter 1, protein absorption, rat, short peptides, small intestine",

author = "Qandeel, {Hisham G.} and Duenes, {Judith A.} and Ye Zheng and Sarr, {Michael G.}",

note = "Funding Information: The authors would like to thank the Mary Elizabeth Groff, Surgical Medical Research and Education Charitable Trust, for the generous funding in support of this work. The authors also thank Dr. Ken-ichi Inui and his research group (Kyoto University, Kyoto, Japan) for providing our lab with the cDNA of rat PEPT1, and Deborah Frank for her secretarial expertise. Funding Information: This research was supported by a grant from the Mary E. Groff Foundation and R01 DK 39337-18 from the National Institutes of Health (MGS). ",

year = "2009",

month = sep,

doi = "10.1016/j.jss.2009.03.052",

language = "English (US)",

volume = "156",

pages = "123--128",

journal = "Journal of Surgical Research",

issn = "0022-4804",

publisher = "Academic Press Inc.",

number = "1",

}

TY - JOUR

T1 - Diurnal Expression and Function of Peptide Transporter 1 (PEPT1)1

AU - Qandeel, Hisham G.

AU - Duenes, Judith A.

AU - Zheng, Ye

AU - Sarr, Michael G.

N1 - Funding Information: The authors would like to thank the Mary Elizabeth Groff, Surgical Medical Research and Education Charitable Trust, for the generous funding in support of this work. The authors also thank Dr. Ken-ichi Inui and his research group (Kyoto University, Kyoto, Japan) for providing our lab with the cDNA of rat PEPT1, and Deborah Frank for her secretarial expertise. Funding Information: This research was supported by a grant from the Mary E. Groff Foundation and R01 DK 39337-18 from the National Institutes of Health (MGS).

PY - 2009/9

Y1 - 2009/9

N2 - Background: Protein is absorbed primarily as di/tripeptides, which are transported into the enterocyte exclusively by H+/peptide cotransporter 1 (PEPT1). Diurnal changes in expression and function of several other mucosal transporters occur in rat. Diurnal variations in mRNA, protein, and transport function of PEPT1 occur in rat duodenum and jejunum, but not in ileum. Methods: Mucosal levels of mRNA and protein were determined at 9 AM, 3 PM, 9 PM, and 3 AM (n = 6 each) by real time RT-PCR and Western blotting, respectively, in rats maintained in a 12-h light/dark room [light 6 AM to 6 PM]; transporter-mediated uptake of dipeptide (Gly-Sar) was also measured by everted sleeve technique. Results: mRNA transcripts of PEPT1 and Gly-Sar uptake varied diurnally in duodenum and jejunum (peak at 3 PM, P < 0.05), but not in ileum; maximal uptake was in jejunum. Vmax (nmol/cm/min) was greater at 3 PM and 9 PM compared with 9 AM (3 PM versus 9 AM: 104 versus 62 in duodenum, and 185 versus 101 in jejunum; P < 0.03); Km was unchanged across time points or locations. Protein levels varied minimally in jejunum and ileum with peaks at 9 PM and 3 AM. Conclusion: Gene expression and transport function of PEPT1 vary diurnally in duodenum and jejunum in temporal association with nocturnal feeding of rats.

AB - Background: Protein is absorbed primarily as di/tripeptides, which are transported into the enterocyte exclusively by H+/peptide cotransporter 1 (PEPT1). Diurnal changes in expression and function of several other mucosal transporters occur in rat. Diurnal variations in mRNA, protein, and transport function of PEPT1 occur in rat duodenum and jejunum, but not in ileum. Methods: Mucosal levels of mRNA and protein were determined at 9 AM, 3 PM, 9 PM, and 3 AM (n = 6 each) by real time RT-PCR and Western blotting, respectively, in rats maintained in a 12-h light/dark room [light 6 AM to 6 PM]; transporter-mediated uptake of dipeptide (Gly-Sar) was also measured by everted sleeve technique. Results: mRNA transcripts of PEPT1 and Gly-Sar uptake varied diurnally in duodenum and jejunum (peak at 3 PM, P < 0.05), but not in ileum; maximal uptake was in jejunum. Vmax (nmol/cm/min) was greater at 3 PM and 9 PM compared with 9 AM (3 PM versus 9 AM: 104 versus 62 in duodenum, and 185 versus 101 in jejunum; P < 0.03); Km was unchanged across time points or locations. Protein levels varied minimally in jejunum and ileum with peaks at 9 PM and 3 AM. Conclusion: Gene expression and transport function of PEPT1 vary diurnally in duodenum and jejunum in temporal association with nocturnal feeding of rats.

KW - PEPT1

KW - diurnal rhythm

KW - peptide transporter 1

KW - protein absorption

KW - rat

KW - short peptides

KW - small intestine

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