The Arabidopsis thaliana trehalase is a plasma membrane-bound enzyme with extracellular activity.
The lack of trehalose accumulation in most plant species has been partly attributed to the presence of an active trehalase. Although trehalose synthesis enzymes are thought to be cytosolic, and previous studies have indicated that trehalase activity is extracellular, the exact location of the enzyme has not yet been established in plant cell. We present evidence that the yet uncharacterised full-length Arabidopsis trehalase is a plasma membrane-bound protein, probably anchored to the membrane through a predicted N-terminal membrane spanning domain. The full-length AtTRE1, when expressed in yeast can functionally substitute for the extracellularly active trehalase Ath1p, by sustaining the growth of an ath1 null mutant strain on trehalose and at pH 4.8. We further demonstrate that AtTRE1 expressed in yeast is plasma membrane-bound as in plant cell. In light of these findings, the regulation of plant cell endogenous trehalose by trehalase is discussed.
Institut des Sciences de la vie, Université catholique de Louvain, Croix du Sud, 5-15, B-1348 Louvain-la-Neuve, Belgium.
Mathieu
M
Frison
Jean Luc
JL
Parrou
Damien
D
Guillaumot
Danièle
D
Masquelier
Jean
J
François
François
F
Chaumont
Henri
H
Batoko
D017360:Arabidopsis / Q000201:enzymology* / Q000235:genetics; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D002462:Cell Membrane / Q000201:enzymology* / Q000235:genetics; D005816:Genetic Complementation Test; D006863:Hydrogen-Ion Concentration; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D017434:Protein Structure, Tertiary / Q000502:physiology; D012441:Saccharomyces cerevisiae / Q000201:enzymology / Q000235:genetics; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism; D014198:Trehalase / Q000235:genetics / Q000378:metabolism*; D014199:Trehalose / Q000235:genetics / Q000378:metabolism*
D029681:Arabidopsis Proteins; D008565:Membrane Proteins; D029701:Saccharomyces cerevisiae Proteins; D014199:Trehalose; D014198:Trehalase