KEGG   PATHWAY: ecb04975
Entry
ecb04975                    Pathway                                
Name
Fat digestion and absorption - Equus caballus (horse)
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
Pathway map
ecb04975  Fat digestion and absorption
ecb04975

Other DBs
GO: 0044241 0030299
Organism
Equus caballus (horse) [GN:ecb]
Gene
100033913  PNLIPRP2; pancreatic lipase-related protein 2 [KO:K14075] [EC:3.1.1.3]
100034050  FABP2; fatty acid-binding protein, intestinal [KO:K08751]
100034202  PNLIP; pancreatic triacylglycerol lipase precursor [KO:K14073] [EC:3.1.1.3]
100037401  PLA2G2A; phospholipase A2, membrane associated [KO:K01047] [EC:3.1.1.4]
100049847  CD36; platelet glycoprotein 4 isoform X1 [KO:K06259]
100049896  PLPP3; phospholipid phosphatase 3 isoform X1 [KO:K01080] [EC:3.1.3.4]
100050467  PLA2G1B; phospholipase A2 [KO:K01047] [EC:3.1.1.4]
100052607  GOT2; aspartate aminotransferase, mitochondrial [KO:K14455] [EC:2.6.1.1]
100052746  FABP1; fatty acid-binding protein, liver [KO:K08750]
100053646  CLPS; colipase A precursor [KO:K14460]
100053803  MTTP; microsomal triglyceride transfer protein large subunit [KO:K14463]
100054241  ABCA1; ATP-binding cassette sub-family A member 1 isoform X2 [KO:K05641]
100054324  PLA2G10; group 10 secretory phospholipase A2 [KO:K01047] [EC:3.1.1.4]
100058509  PLA2G3; group 3 secretory phospholipase A2 [KO:K01047] [EC:3.1.1.4]
100058536  PLA2G5; calcium-dependent phospholipase A2 [KO:K01047] [EC:3.1.1.4]
100058892  ACAT2; acetyl-CoA acetyltransferase, cytosolic [KO:K00626] [EC:2.3.1.9]
100059501  AGPAT1; 1-acyl-sn-glycerol-3-phosphate acyltransferase alpha [KO:K13509] [EC:2.3.1.51]
100060232  MOGAT3; LOW QUALITY PROTEIN: 2-acylglycerol O-acyltransferase 3 [KO:K14456] [EC:2.3.1.20 2.3.1.22]
100061529  SCARB1; scavenger receptor class B member 1 isoform X1 [KO:K13885]
100062257  PLPP1; phospholipid phosphatase 1 isoform X2 [KO:K01080] [EC:3.1.3.4]
100062284  [KO:K14452] [EC:3.1.1.3]
100062506  APOA4; apolipoprotein A-IV [KO:K08760]
100062583  APOA1; apolipoprotein A-I [KO:K08757]
100063726  PLA2G12B; group XIIB secretory phospholipase A2-like protein isoform X1 [KO:K01047] [EC:3.1.1.4]
100064387  DGAT2; diacylglycerol O-acyltransferase 2 [KO:K11160] [EC:2.3.1.20 2.3.1.75]
100064445  MOGAT2; LOW QUALITY PROTEIN: 2-acylglycerol O-acyltransferase 2 [KO:K14457] [EC:2.3.1.22]
100065105  NPC1L1; Niemann-Pick C1-like protein 1 [KO:K14461]
100066592  CEL; bile salt-activated lipase [KO:K12298] [EC:3.1.1.3 3.1.1.13]
100067009  SLC27A4; long-chain fatty acid transport protein 4 [KO:K08745] [EC:6.2.1.-]
100067744  PNLIPRP1; inactive pancreatic lipase-related protein 1 [KO:K14074] [EC:3.1.1.3]
100068797  AGPAT2; 1-acyl-sn-glycerol-3-phosphate acyltransferase beta isoform X1 [KO:K13509] [EC:2.3.1.51]
100069071  ABCG8; ATP-binding cassette sub-family G member 8 [KO:K05684]
100069091  ABCG5; ATP-binding cassette sub-family G member 5 [KO:K05683]
100069718  ACAT1; acetyl-CoA acetyltransferase, mitochondrial [KO:K00626] [EC:2.3.1.9]
100070188  SLC27A1; long-chain fatty acid transport protein 1 isoform X1 [KO:K08745] [EC:6.2.1.-]
100071214  [KO:K01047] [EC:3.1.1.4]
100071675  [KO:K14452] [EC:3.1.1.3]
100071824  APOB; apolipoprotein B-100 [KO:K14462]
100071826  PLA2G2C; putative inactive group IIC secretory phospholipase A2 isoform X1 [KO:K01047] [EC:3.1.1.4]
100071833  PLA2G2F; group IIF secretory phospholipase A2 [KO:K01047] [EC:3.1.1.4]
100071838  PLA2G2D; group IID secretory phospholipase A2 [KO:K01047] [EC:3.1.1.4]
100071870  PLA2G2E; group IIE secretory phospholipase A2 [KO:K01047] [EC:3.1.1.4]
100072858  PLA2G12A; group XIIA secretory phospholipase A2 [KO:K01047] [EC:3.1.1.4]
100147309  PLPP2; phospholipid phosphatase 2 isoform X1 [KO:K01080] [EC:3.1.3.4]
100147359  DGAT1; diacylglycerol O-acyltransferase 1 isoform X2 [KO:K11155] [EC:2.3.1.20 2.3.1.75 2.3.1.76]
111771795  [KO:K14452] [EC:3.1.1.3]
111771944  [KO:K14452] [EC:3.1.1.3]
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
PMID:19158321
  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
PMID:20522896
  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
PMID:19280719
  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
PMID:15286736
  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
PMID:20148678
  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
PMID:19116371
  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
PMID:10924713
  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
PMID:12621063
  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
PMID:17495606
  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
PMID:18830418
  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
PMID:11504671
  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
PMID:14976303
  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
PMID:17002594
  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
PMID:19663632
  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
PMID:15891388
  Authors
Hussain MM, Fatma S, Pan X, Iqbal J
  Title
Intestinal lipoprotein assembly.
  Journal
Curr Opin Lipidol 16:281-5 (2005)
DOI:10.1097/01.mol.0000169347.53568.5a
Reference
PMID:20493784
  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
Related
pathway
ecb00561  Glycerolipid metabolism
ecb04530  Tight junction
ecb04972  Pancreatic secretion
ecb04976  Bile secretion
KO pathway
ko04975   

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