Note: a dashed line (without arrowheads) between two compound names is meant to imply that the two names are just different instantiations of the same compound -- i.e. one may be a specific name and the other a general name, or they may both represent the same compound in different stages of a polymerization-type pathway. This view shows enzymes only for those organisms listed below, in the list of taxa known to possess the pathway. If an enzyme name is shown in bold, there is experimental evidence for this enzymatic activity.
|Superclasses:||Degradation/Utilization/Assimilation → Carbohydrates Degradation → Sugars Degradation → Trehalose Degradation|
There are several alternative pathways for the degradation of trehalose. Depending on the organism, trehalose may enter the cell either through a permease, in which case it remains unmodified, or it may be transported by a phosphotransferase system (PTS), resulting in the phoshorylated trehalose-6-phosphate form. Degradation then proceeds by different mechanisms: Unmodified trehalose may be degraded by a hydrolyzing trehalase (see trehalose degradation II (trehalase)), or it may be split by the action of a trehalose phosphorylase (see trehalose degradation IV and trehalose degradation V). Likewise, trehalose-6-phosphate may be either hydrolyzed by trehalose-6-phosphate hydrolase (see trehalose degradation I (low osmolarity)) or it could be attacked by a trehalose-6-phosphate phosphorylase (see trehalose degradation III).
In insects, trehalose is produced from fat body glycogen and is released into the hemolymph. In many insects, trehalose serves as an extracellular source of sugar via the action of trehalase, an enzyme widely distributed in insect tissues (reviewed in [Kramer05, Arrese10]).
About This Pathway
Escherichia coli K-12 can grow with trehalose as the sole carbon source, and employs different pathways for its degradation under different osmolarity conditions. Under high osmotic conditions external trehalose is hydrolyzed by periplasmic trehalase (TreA) [Boos87]. The resulting glucose molecules are then transported back into the cytoplasm through the glucose PTS [Styrvold91] (see trehalose degradation VI (periplasmic)).
A second trehalase, the cytoplasmic trehalase (TreF), is active during the transition period between high and low osmolarity. As the cells are shifting their metabolism to adjust to low osmolarity, TreF removes the internal pool of trehalose. The relatively low enzymatic activity of TreF is low enough not to compromise the biosynthesis of trehalose during high osmolarity, yet is sufficient to degrade the accumulated trehalose after the return to normal conditions, when no more biosynthesis occurrs [Horlacher96].
This trehalose degradation pathway is also used by the yeast Saccharomyces cerevisiae. This organism also has a cytoplasmic and a periplasmic trehalase enzymes [Kopp93]. Nth1p, the cytoplasmic enzyme, is required for the hydrolysis of intracellular trehalose, while Ath1p, the periplasmic enzyme, hydrolyzes extracellular trehalose [Jules04].
Superpathways: chitin biosynthesis
Unification Links: EcoCyc:PWY0-1182
Boos87: Boos W, Ehmann U, Bremer E, Middendorf A, Postma P (1987). "Trehalase of Escherichia coli. Mapping and cloning of its structural gene and identification of the enzyme as a periplasmic protein induced under high osmolarity growth conditions." J Biol Chem 1987;262(27);13212-8. PMID: 2820965
Jules04: Jules M, Guillou V, Francois J, Parrou JL (2004). "Two distinct pathways for trehalose assimilation in the yeast Saccharomyces cerevisiae." Appl Environ Microbiol 70(5);2771-8. PMID: 15128531
Styrvold91: Styrvold OB, Strom AR (1991). "Synthesis, accumulation, and excretion of trehalose in osmotically stressed Escherichia coli K-12 strains: influence of amber suppressors and function of the periplasmic trehalase." J Bacteriol 173(3);1187-92. PMID: 1825082
Alizadeh96: Alizadeh P, Klionsky DJ (1996). "Purification and biochemical characterization of the ATH1 gene product, vacuolar acid trehalase, from Saccharomyces cerevisiae." FEBS Lett 391(3);273-8. PMID: 8764988
Cardona09: Cardona F, Parmeggiani C, Faggi E, Bonaccini C, Gratteri P, Sim L, Gloster TM, Roberts S, Davies GJ, Rose DR, Goti A (2009). "Total syntheses of casuarine and its 6-O-alpha-glucoside: complementary inhibition towards glycoside hydrolases of the GH31 and GH37 families." Chemistry 15(7);1627-36. PMID: 19123216
Crowe94: Crowe LM, Spargo BJ, Ioneda T, Beaman BL, Crowe JH (1994). "Interaction of cord factor (alpha, alpha'-trehalose-6,6'-dimycolate) with phospholipids." Biochim Biophys Acta 1194(1);53-60. PMID: 8075141
Curtis75: Curtis SJ, Epstein W (1975). "Phosphorylation of D-glucose in Escherichia coli mutants defective in glucosephosphotransferase, mannosephosphotransferase, and glucokinase." J Bacteriol 122(3);1189-99. PMID: 1097393
Dai99: Dai N, Schaffer A, Petreikov M, Shahak Y, Giller Y, Ratner K, Levine A, Granot D (1999). "Overexpression of Arabidopsis hexokinase in tomato plants inhibits growth, reduces photosynthesis, and induces rapid senescence." Plant Cell 11(7);1253-66. PMID: 10402427
Destruelle95: Destruelle M, Holzer H, Klionsky DJ (1995). "Isolation and characterization of a novel yeast gene, ATH1, that is required for vacuolar acid trehalase activity." Yeast 11(11);1015-25. PMID: 7502577
DiazMejia09: Diaz-Mejia JJ, Babu M, Emili A (2009). "Computational and experimental approaches to chart the Escherichia coli cell-envelope-associated proteome and interactome." FEMS Microbiol Rev 33(1);66-97. PMID: 19054114
Fraenkel64: FRAENKEL DG, FALCOZ-KELLY F, HORECKER BL (1964). "THE UTILIZATION OF GLUCOSE 6-PHOSPHATE BY GLUCOKINASELESS AND WILD-TYPE STRAINS OF ESCHERICHIA COLI." Proc Natl Acad Sci U S A 52;1207-13. PMID: 14231443
Garre09: Garre E, Matallana E (2009). "The three trehalases Nth1p, Nth2p and Ath1p participate in the mobilization of intracellular trehalose required for recovery from saline stress in Saccharomyces cerevisiae." Microbiology 155(Pt 9);3092-9. PMID: 19520725
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