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

external resources
NCBI:172847
KEGG:hsa04974
PUBMED:15772300
PUBMED:18195088
PUBMED:9687539
PUBMED:18400692
PUBMED:12583961
PUBMED:18626068
PUBMED:20522896
PUBMED:14977407
PUBMED:7937532
PUBMED:11546643
PUBMED:20093818
PUBMED:16887608
PUBMED:12237156

genes
ATP1A1 , ATP1A2 , ATP1A3 , ATP1A4 , ATP1B1 , ATP1B2 , ATP1B3 , FXYD2 , COL1A1 , COL1A2 , COL2A1 , COL3A1 , COL4A1 , COL4A2 , COL4A3 , COL4A4 , COL4A5 , COL4A6 , COL5A1 , COL5A2 , COL6A1 , COL6A2 , COL6A3 , COL7A1 , COL9A1 , COL9A2 , COL9A3 , COL10A1 , COL11A1 , COL11A2 , COL12A1 , COL13A1 , COL15A1 , COL17A1 , CPA1 , CPA2 , CPA3 , CPB1 , CPB2 , CTRB1 , CTRL , DPP4 , ELN , KCNJ13 , KCNN4 , KCNQ1 , MEP1A , MEP1B , MME , PGA5 , PRCP , PRSS1 , PRSS3 , SLC1A1 , SLC1A5 , SLC3A1 , SLC3A2 , SLC8A2 , SLC8A1 , SLC8A3 , SLC9A3 , SLC15A1 , COL14A1 , XPNPEP2 , KCNK5 , SLC7A7 , KCNE3 , CELA3A , SLC7A9 , SLC7A8 , CELA3B , ATP1B4 , COL5A3 , CELA2B , SLC38A2 , ACE2 , CELA2A , COL18A1 , COL21A1 , COL27A1 , SLC16A10 , COL6A6 , COL22A1 , SLC36A1 , COL24A1 , COL6A5 , SLC6A19 , PGA3 , PGA4 ,