KEGG   PATHWAY: map04974Help
Entry
map04974                    Pathway                                

Name
Protein digestion and absorption
Description
Protein is a dietary component essential for nutritional homeostasis in humans. Normally, ingested protein undergoes a complex series of degradative processes following the action of gastric, pancreatic and small intestinal enzymes. The result of this proteolytic activity is a mixture of amino acids and small peptides. Amino acids (AAs) are transported into the enterocyte (intestinal epithelial cell) by a variety of AA transporters that are specific for cationic (basic) AA, neutral AA, and anionic (acidic) AA. Small peptides are absorbed into enterocytes by the PEPT1 transporter. Inside enterocytes peptides are hydrolyzed, and the resulting amino acids are released together with those absorbed by AA transporters into blood via multiple, basolateral, AA transporters. Hydrolysis-resistant peptides, however, are transported out of the cells by a basolateral peptide transporter that has not been identified molecularly.
Class
Organismal Systems; Digestive system
BRITE hierarchy
Pathway map
map04974  Protein digestion and absorption
map04974

Ortholog table
Disease
H00843  Hartnup disorder
H00899  Lysinuric protein intolerance
H00901  Cystinuria
H00905  Iminoglycinuria
H00911  Dicarboxylic aminoaciduria
H00933  Hereditary pancreatitis
H01304  Hyperglycinuria
Other DBs
GO: 0044256 0050892
Reference
  Authors
Broer S
  Title
Amino acid transport across mammalian intestinal and renal epithelia.
  Journal
Physiol Rev 88:249-86 (2008)
DOI:10.1152/physrev.00018.2006
Reference
  Authors
Palacin M, Nunes V, Font-Llitjos M, Jimenez-Vidal M, Fort J, Gasol E, Pineda M, Feliubadalo L, Chillaron J, Zorzano A
  Title
The genetics of heteromeric amino acid transporters.
  Journal
Physiology (Bethesda) 20:112-24 (2005)
DOI:10.1152/physiol.00051.2004
Reference
  Authors
Goodman BE
  Title
Insights into digestion and absorption of major nutrients in humans.
  Journal
Adv Physiol Educ 34:44-53 (2010)
DOI:10.1152/advan.00094.2009
Reference
  Authors
Wagner CA, Lang F, Broer S
  Title
Function and structure of heterodimeric amino acid transporters.
  Journal
Am J Physiol Cell Physiol 281:C1077-93 (2001)
DOI:10.1152/ajpcell.2001.281.4.C1077
Reference
  Authors
Broer S
  Title
Apical transporters for neutral amino acids: physiology and pathophysiology.
  Journal
Physiology (Bethesda) 23:95-103 (2008)
DOI:10.1152/physiol.00045.2007
Reference
PMID:9687539
  Authors
Wu G
  Title
Intestinal mucosal amino acid catabolism.
  Journal
J Nutr 128:1249-52 (1998)
DOI:10.1093/jn/128.8.1249
Reference
  Authors
Daniel H
  Title
Molecular and integrative physiology of intestinal peptide transport.
  Journal
Annu Rev Physiol 66:361-84 (2004)
DOI:10.1146/annurev.physiol.66.032102.144149
Reference
  Authors
Rubio-Aliaga I, Daniel H
  Title
Mammalian peptide transporters as targets for drug delivery.
  Journal
Trends Pharmacol Sci 23:434-40 (2002)
DOI:10.1016/S0165-6147(02)02072-2
Reference
PMID:7937532
  Authors
Bai JP
  Title
Distribution of brush-border membrane peptidases along the rat intestine.
  Journal
Pharm Res 11:897-900 (1994)
Reference
  Authors
Guarner F, Malagelada JR
  Title
Gut flora in health and disease.
  Journal
Lancet 361:512-9 (2003)
DOI:10.1016/S0140-6736(03)12489-0
Reference
  Authors
Smith EA, Macfarlane GT
  Title
Dissimilatory amino Acid metabolism in human colonic bacteria.
  Journal
Anaerobe 3:327-37 (1997)
DOI:10.1006/anae.1997.0121
Reference
  Authors
Schepers E, Glorieux G, Vanholder R
  Title
The gut: the forgotten organ in uremia?
  Journal
Blood Purif 29:130-6 (2010)
DOI:10.1159/000245639
Reference
  Authors
John H.Cummings
  Title
The large intestine in nutrition and disease
  Journal
Institut Danone
Reference
  Authors
Heitzmann D, Warth R
  Title
Physiology and pathophysiology of potassium channels in gastrointestinal epithelia.
  Journal
Physiol Rev 88:1119-82 (2008)
DOI:10.1152/physrev.00020.2007
KO pathway
ko04974   

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