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
Fat digestion and absorption
ko04975

All organismsOrtholog table
Disease
H00845  
Familial amyloidosis
H00930  
Hypoalphalipoproteinemia
H01108  
CD36 deficiency
H01213  
Gallbladder disease
H01270  
Familial hypobetalipoproteinemia (FHBL)
Other DBs
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
C02530  
Cholesterol ester
Reference
  Authors
Iqbal J, Hussain MM
  Title
Intestinal lipid absorption.
  Journal
Am J Physiol Endocrinol Metab 296:E1183-94 (2009)
Reference
  Authors
Goodman BE
  Title
Insights into digestion and absorption of major nutrients in humans.
  Journal
Adv Physiol Educ 34:44-53 (2010)
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)
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)
Reference
  Authors
Mansbach CM, Siddiqi SA
  Title
The biogenesis of chylomicrons.
  Journal
Annu Rev Physiol 72:315-33 (2010)
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)
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)
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)
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)
Reference
  Authors
Williams KJ
  Title
Molecular processes that handle -- and mishandle -- dietary lipids.
  Journal
J Clin Invest 118:3247-59 (2008)
Reference
  Authors
Lu K, Lee MH, Patel SB
  Title
Dietary cholesterol absorption; more than just bile.
  Journal
Trends Endocrinol Metab 12:314-20 (2001)
Reference
  Authors
Klett EL, Patel SB
  Title
Biomedicine. Will the real cholesterol transporter please stand up.
  Journal
Science 303:1149-50 (2004)
Reference
  Authors
Wang DQ
  Title
Regulation of intestinal cholesterol absorption.
  Journal
Annu Rev Physiol 69:221-48 (2007)
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)
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)

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