Purification and molecular analysis of an extracellular gamma-glutamyl hydrolase present in young tissues of the soybean plant.
A polypeptide present in intercellular wash fluids of young leaves of Glycine max has been purified to electrophoretic homogeneity. The protein has been identified as gamma-glutamyl hydrolase (GGH) based on the shared homology with a recently cloned cDNA from rat. The enzyme is present within the extracellular space of young leaves and a portion is bound to the cell wall. Northern and Western analysis confirm that this polypeptide is expressed only in young (1-15 d old) leaf, stem and root tissue and is therefore expressed under a strict developmental program. The primary sequence of gamma-glutamyl hydrolase shares amino acid identity with a cDNA clone from rat and two partially sequenced cDNAs from Arabidopsis. Although the complete in vivo function of gamma-glutamyl hydrolase in plants is unclear, it is known that the protein plays a critical role in folate metabolism and therefore likely in meeting the physiological demands of growing plant tissues.
Huangpu
J
J
Department of Biological Sciences, Bowling Green State University, Ohio 43403, USA.
Pak
J H
JH
Graham
M C
MC
Rickle
S A
SA
Graham
J S
JS
D015153:Blotting, Western; D002473:Cell Wall / Q000201:enzymology; D003429:Cross Reactions; D018076:DNA, Complementary / Q000235:genetics; D015870:Gene Expression; D008666:Metalloendopeptidases / Q000276:immunology; D008969:Molecular Sequence Data; D018515:Plant Leaves / Q000201:enzymology*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D018749:RNA, Plant / Q000235:genetics / Q000378:metabolism; D013025:Glycine max / Q000201:enzymology*; D011623:gamma-Glutamyl Hydrolase / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism
D018076:DNA, Complementary; D012333:RNA, Messenger; D018749:RNA, Plant; D011623:gamma-Glutamyl Hydrolase; D008666:Metalloendopeptidases