KEGG   PATHWAY: ko04975Help
Entry
ko04975                     Pathway                                

Name
Fat digestion and absorption
Description
Fat is an important energy source from food. More than 95% of dietary fat is long-chain triacylglycerols (TAG), the remaining being phospholipids (4.5%) and sterols. In the small intestine lumen, dietary TAG is hydrolyzed to fatty acids (FA) and monoacylglycerols (MAG) by pancreatic lipase. These products are then emulsified with the help of phospholipids (PL) and bile acids (BA) present in bile to form micelles. Free FAs and MAGs are taken up by the enterocyte where they are rapidly resynthesized in endoplasmic reticulum (ER) to form TAG. PLs from the diet as well as bile - mainly LPA - too are absorbed by the enterocyte and are acylated to form phosphatidic acid (PA), which is also converted into TAG. Absorbed cholesterol (CL) is acylated to cholesterol esters (CE). Within the ER, TAG joins CE and apolipoprotein B (ApoB) to form chylomicrons that enter circulation through the lymph.
Class
Organismal Systems; Digestive system
BRITE hierarchy
Pathway map
ko04975  Fat digestion and absorption
ko04975

Ortholog table
Disease
H00845  Familial amyloidosis
H00930  Hypoalphalipoproteinemia
H01108  CD36 deficiency
H01213  Gallbladder disease
H01270  Familial hypobetalipoproteinemia (FHBL)
Other DBs
BSID: 194324
GO: 0044241 0030299
Orthology
K14452  gastric triacylglycerol lipase [EC:3.1.1.3]
K14073  pancreatic triacylglycerol lipase [EC:3.1.1.3]
K14074  pancreatic lipase-related protein 1 [EC:3.1.1.3]
K14075  pancreatic lipase-related protein 2 [EC:3.1.1.3]
K12298  bile salt-stimulated lipase [EC:3.1.1.3 3.1.1.13]
K01047  secretory phospholipase A2 [EC:3.1.1.4]
K14460  colipase
K06259  CD36 antigen
K14455  aspartate aminotransferase, mitochondrial [EC:2.6.1.1]
K08751  fatty acid-binding protein 2, intestinal
K08750  fatty acid-binding protein 1, liver
K13509  lysophosphatidate acyltransferase [EC:2.3.1.51]
K01080  phosphatidate phosphatase [EC:3.1.3.4]
K14457  2-acylglycerol O-acyltransferase 2 [EC:2.3.1.22]
K14456  2-acylglycerol O-acyltransferase 3 [EC:2.3.1.22 2.3.1.20]
K11155  diacylglycerol O-acyltransferase 1 [EC:2.3.1.76 2.3.1.75 2.3.1.20]
K11160  diacylglycerol O-acyltransferase 2 [EC:2.3.1.75 2.3.1.20]
K13885  scavenger receptor class B, member 1
K14461  Niemann-Pick C1-like protein 1
K05683  ATP-binding cassette, subfamily G (WHITE), member 5 (sterolin 1)
K05684  ATP-binding cassette, subfamily G (WHITE), member 8 (sterolin 2)
K08760  apolipoprotein A-IV
K14462  apolipoprotein B
K14463  microsomal triglyceride transfer protein large subunit
K08757  apolipoprotein A-I
K05641  ATP-binding cassette, subfamily A (ABC1), member 1
Compound
C00010  CoA
C00040  Acyl-CoA
C00162  Fatty acid
C00165  Diacylglycerol
C00187  Cholesterol
C00416  Phosphatidate
C00422  Triacylglycerol
C00681  1-Acyl-sn-glycerol 3-phosphate
C00865  Phospholipid
C01558  Bile salt
C01885  1-Acylglycerol
C02112  2-Acylglycerol
C02530  Cholesterol ester
Reference
  Authors
Iqbal J, Hussain MM
  Title
Intestinal lipid absorption.
  Journal
Am J Physiol Endocrinol Metab 296:E1183-94 (2009)
DOI:10.1152/ajpendo.90899.2008
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
Niot I, Poirier H, Tran TT, Besnard P
  Title
Intestinal absorption of long-chain fatty acids: evidence and uncertainties.
  Journal
Prog Lipid Res 48:101-15 (2009)
DOI:10.1016/j.plipres.2009.01.001
Reference
  Authors
Shi Y, Burn P
  Title
Lipid metabolic enzymes: emerging drug targets for the treatment of obesity.
  Journal
Nat Rev Drug Discov 3:695-710 (2004)
DOI:10.1038/nrd1469
Reference
  Authors
Mansbach CM, Siddiqi SA
  Title
The biogenesis of chylomicrons.
  Journal
Annu Rev Physiol 72:315-33 (2010)
DOI:10.1146/annurev-physiol-021909-135801
Reference
  Authors
Shi Y, Cheng D
  Title
Beyond triglyceride synthesis: the dynamic functional roles of MGAT and DGAT enzymes in energy metabolism.
  Journal
Am J Physiol Endocrinol Metab 297:E10-8 (2009)
DOI:10.1152/ajpendo.90949.2008
Reference
  Authors
Ros E
  Title
Intestinal absorption of triglyceride and cholesterol. Dietary and pharmacological inhibition to reduce cardiovascular risk.
  Journal
Atherosclerosis 151:357-79 (2000)
DOI:10.1016/S0021-9150(00)00456-1
Reference
  Authors
Yen CL, Farese RV Jr
  Title
MGAT2, a monoacylglycerol acyltransferase expressed in the small intestine.
  Journal
J Biol Chem 278:18532-7 (2003)
DOI:10.1074/jbc.M301633200
Reference
  Authors
Levy E, Spahis S, Sinnett D, Peretti N, Maupas-Schwalm F, Delvin E, Lambert M, Lavoie MA
  Title
Intestinal cholesterol transport proteins: an update and beyond.
  Journal
Curr Opin Lipidol 18:310-8 (2007)
DOI:10.1097/MOL.0b013e32813fa2e2
Reference
  Authors
Williams KJ
  Title
Molecular processes that handle -- and mishandle -- dietary lipids.
  Journal
J Clin Invest 118:3247-59 (2008)
DOI:10.1172/JCI35206
Reference
  Authors
Lu K, Lee MH, Patel SB
  Title
Dietary cholesterol absorption; more than just bile.
  Journal
Trends Endocrinol Metab 12:314-20 (2001)
DOI:10.1016/S1043-2760(01)00433-7
Reference
  Authors
Klett EL, Patel SB
  Title
Biomedicine. Will the real cholesterol transporter please stand up.
  Journal
Science 303:1149-50 (2004)
DOI:10.1126/science.1095519
Reference
  Authors
Wang DQ
  Title
Regulation of intestinal cholesterol absorption.
  Journal
Annu Rev Physiol 69:221-48 (2007)
DOI:10.1146/annurev.physiol.69.031905.160725
Reference
  Authors
Patel JP, Brocks DR
  Title
The effect of oral lipids and circulating lipoproteins on the metabolism of drugs.
  Journal
Expert Opin Drug Metab Toxicol 5:1385-98 (2009)
DOI:10.1517/17425250903176439
Reference
  Authors
Hussain MM, Fatma S, Pan X, Iqbal J
  Title
Intestinal lipoprotein assembly.
  Journal
Curr Opin Lipidol 16:281-5 (2005)
Reference
  Authors
Kindel T, Lee DM, Tso P
  Title
The mechanism of the formation and secretion of chylomicrons.
  Journal
Atheroscler Suppl 11:11-6 (2010)
DOI:10.1016/j.atherosclerosissup.2010.03.003

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