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Pathway Description
Lactose Degradation
Rattus norvegicus
Category:
Metabolite Pathway
Sub-Category:
Metabolic
Created: 2018-08-10
Last Updated: 2019-08-16
Lactose degradation (Lactose metabolism) shows the breakdown of alpha lactose into its constituent sugars, which are then utilized by the body as an energy source. Alpha-Lactose is the major sugar present in milk and the main source of energy supplied to the newborn mammalian in its mother’s milk. Lactose is also an important osmotic regulator of lactation. It is digested by the intestinal lactase, an enzyme expressed in newborns. Its activity declines following weaning. Lactase hydrolyzes alpha lactose into D-glucose and D-galactose, which are actively transported into the intestinal epithelial cells via the SGLT1 (GLUT1) cotransporter. GLUT1 actively transports glucose and galactose with 2 sodium ions. A sodium/potassium ATPase makes ATP by moving three sodium ions to the blood per two potassium ions that cross into the epithelial cell, giving the GLUT1 transporter energy to work. D-glucose and D-galactose diffuse into the blood, facilitated by the SLC2A2 transporter on the basolateral membrane on the intestinal epithelial cells. The sugars are then transported to liver.
References
Lactose Degradation References
Duluc I, Boukamel R, Mantei N, Semenza G, Raul F, Freund JN: Sequence of the precursor of intestinal lactase-phlorizin hydrolase from fetal rat. Gene. 1991 Jul 22;103(2):275-6. doi: 10.1016/0378-1119(91)90286-k.
Pubmed: 1909681
Boukamel R, Freund JN: The rat LPH gene 5' region: comparative structure with the human gene. DNA Seq. 1992;3(2):119-21.
Pubmed: 1339333
Buller HA, Kothe MJ, Goldman DA, Grubman SA, Sasak WV, Matsudaira PT, Montgomery RK, Grand RJ: Coordinate expression of lactase-phlorizin hydrolase mRNA and enzyme levels in rat intestine during development. J Biol Chem. 1990 Apr 25;265(12):6978-83.
Pubmed: 1691182
Shull GE, Greeb J, Lingrel JB: Molecular cloning of three distinct forms of the Na+,K+-ATPase alpha-subunit from rat brain. Biochemistry. 1986 Dec 16;25(25):8125-32. doi: 10.1021/bi00373a001.
Pubmed: 3028470
Hara Y, Urayama O, Kawakami K, Nojima H, Nagamune H, Kojima T, Ohta T, Nagano K, Nakao M: Primary structures of two types of alpha-subunit of rat brain Na+,K+,-ATPase deduced from cDNA sequences. J Biochem. 1987 Jul;102(1):43-58. doi: 10.1093/oxfordjournals.jbchem.a122039.
Pubmed: 2822682
Herrera VL, Emanuel JR, Ruiz-Opazo N, Levenson R, Nadal-Ginard B: Three differentially expressed Na,K-ATPase alpha subunit isoforms: structural and functional implications. J Cell Biol. 1987 Oct;105(4):1855-65. doi: 10.1083/jcb.105.4.1855.
Pubmed: 2822726
Gerhard DS, Wagner L, Feingold EA, Shenmen CM, Grouse LH, Schuler G, Klein SL, Old S, Rasooly R, Good P, Guyer M, Peck AM, Derge JG, Lipman D, Collins FS, Jang W, Sherry S, Feolo M, Misquitta L, Lee E, Rotmistrovsky K, Greenhut SF, Schaefer CF, Buetow K, Bonner TI, Haussler D, Kent J, Kiekhaus M, Furey T, Brent M, Prange C, Schreiber K, Shapiro N, Bhat NK, Hopkins RF, Hsie F, Driscoll T, Soares MB, Casavant TL, Scheetz TE, Brown-stein MJ, Usdin TB, Toshiyuki S, Carninci P, Piao Y, Dudekula DB, Ko MS, Kawakami K, Suzuki Y, Sugano S, Gruber CE, Smith MR, Simmons B, Moore T, Waterman R, Johnson SL, Ruan Y, Wei CL, Mathavan S, Gunaratne PH, Wu J, Garcia AM, Hulyk SW, Fuh E, Yuan Y, Sneed A, Kowis C, Hodgson A, Muzny DM, McPherson J, Gibbs RA, Fahey J, Helton E, Ketteman M, Madan A, Rodrigues S, Sanchez A, Whiting M, Madari A, Young AC, Wetherby KD, Granite SJ, Kwong PN, Brinkley CP, Pearson RL, Bouffard GG, Blakesly RW, Green ED, Dickson MC, Rodriguez AC, Grimwood J, Schmutz J, Myers RM, Butterfield YS, Griffith M, Griffith OL, Krzywinski MI, Liao N, Morin R, Palmquist D, Petrescu AS, Skalska U, Smailus DE, Stott JM, Schnerch A, Schein JE, Jones SJ, Holt RA, Baross A, Marra MA, Clifton S, Makowski KA, Bosak S, Malek J: The status, quality, and expansion of the NIH full-length cDNA project: the Mammalian Gene Collection (MGC). Genome Res. 2004 Oct;14(10B):2121-7. doi: 10.1101/gr.2596504.
Pubmed: 15489334
Kawakami K, Yagawa Y, Nagano K: Regulation of Na+,K(+)-ATPases. I. Cloning and analysis of the 5'-flanking region of the rat NKAA2 gene encoding the alpha 2 subunit. Gene. 1990 Jul 16;91(2):267-70. doi: 10.1016/0378-1119(90)90098-c.
Pubmed: 2170235
Shamraj OI, Lingrel JB: A putative fourth Na+,K(+)-ATPase alpha-subunit gene is expressed in testis. Proc Natl Acad Sci U S A. 1994 Dec 20;91(26):12952-6. doi: 10.1073/pnas.91.26.12952.
Pubmed: 7809153
Jimenez T, Sanchez G, Wertheimer E, Blanco G: Activity of the Na,K-ATPase alpha4 isoform is important for membrane potential, intracellular Ca2+, and pH to maintain motility in rat spermatozoa. Reproduction. 2010 May;139(5):835-45. doi: 10.1530/REP-09-0495. Epub 2010 Feb 23.
Pubmed: 20179187
Mercer RW, Schneider JW, Savitz A, Emanuel J, Benz EJ Jr, Levenson R: Rat-brain Na,K-ATPase beta-chain gene: primary structure, tissue-specific expression, and amplification in ouabain-resistant HeLa C+ cells. Mol Cell Biol. 1986 Nov;6(11):3884-90. doi: 10.1128/mcb.6.11.3884.
Pubmed: 3025616
Young RM, Shull GE, Lingrel JB: Multiple mRNAs from rat kidney and brain encode a single Na+,K+-ATPase beta subunit protein. J Biol Chem. 1987 Apr 5;262(10):4905-10.
Pubmed: 3031033
Mercer RW, Biemesderfer D, Bliss DP Jr, Collins JH, Forbush B 3rd: Molecular cloning and immunological characterization of the gamma polypeptide, a small protein associated with the Na,K-ATPase. J Cell Biol. 1993 May;121(3):579-86. doi: 10.1083/jcb.121.3.579.
Pubmed: 8387529
Therien AG, Karlish SJ, Blostein R: Expression and functional role of the gamma subunit of the Na, K-ATPase in mammalian cells. J Biol Chem. 1999 Apr 30;274(18):12252-6. doi: 10.1074/jbc.274.18.12252.
Pubmed: 10212192
Arystarkhova E, Wetzel RK, Sweadner KJ: Distribution and oligomeric association of splice forms of Na(+)-K(+)-ATPase regulatory gamma-subunit in rat kidney. Am J Physiol Renal Physiol. 2002 Mar;282(3):F393-407. doi: 10.1152/ajprenal.00146.2001.
Pubmed: 11832419
Lee WS, Kanai Y, Wells RG, Hediger MA: The high affinity Na+/glucose cotransporter. Re-evaluation of function and distribution of expression. J Biol Chem. 1994 Apr 22;269(16):12032-9.
Pubmed: 8163506
Aoshima H, Yokoyama T, Tanizaki J, Izu H, Yamada M: The sugar specificity of Na+/glucose cotransporter from rat jejunum. Biosci Biotechnol Biochem. 1997 Jun;61(6):979-83. doi: 10.1271/bbb.61.979.
Pubmed: 9214758
This pathway was propagated using PathWhiz -
Pon, A. et al. Pathways with PathWhiz (2015) Nucleic Acids Res. 43(Web Server issue): W552–W559.
Propagated from SMP0000457
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