TY - JOUR
T1 - The Tetrahymena homolog of bacterial and mammalian 4-hydroxyphenylpyruvate dioxygenases localizes to membranes of the endoplasmic reticulum
AU - Neve, S
AU - Tornehave, D
AU - Corydon, T J
AU - Kristiansen, K
N1 - Keywords: 4-Hydroxyphenylpyruvate Dioxygenase; Animals; Bacteria; Endoplasmic Reticulum; Intracellular Membranes; Mammals; Recombinant Fusion Proteins; Tetrahymena thermophila; Vacuoles
PY - 1999
Y1 - 1999
N2 - The expression and intracellular localization of the Tetrahymena homolog of 4-hydroxyphenylpyruvate dioxygenase (HPPD) were investigated in wild-type Tetrahymena thermophila strain B1868 VII and the mutant strains IIG8, defective in food vacuole formation, MS-1, blocked in secretion of lysosomal enzymes, and SB 281, defective in mucocyst maturation. Immunoelectron microscopy and confocal laser scanning microscopy demonstrated that Tetrahymena HPPD primarily localized to membranes of the endoplasmic reticulum. In addition, Tetrahymena HPPD was detected in association with membranes of the Golgi apparatus, and transport vesicles in exponentially growing wild-type and mutant strains. In starved cells, Tetrahymena HPPD localized exclusively to membranes of small vesicles. Since no de novo synthesis of Tetrahymena HPPD takes place in cells starved for more than 30 min, these results suggest that there is a flow of Tetrahymena HPPD from the endoplasmic reticulum to small vesicles, possibly via the Golgi apparatus, and that Tetrahymena HPPD contains a signal for vesicle membrane retrieval or retention.
AB - The expression and intracellular localization of the Tetrahymena homolog of 4-hydroxyphenylpyruvate dioxygenase (HPPD) were investigated in wild-type Tetrahymena thermophila strain B1868 VII and the mutant strains IIG8, defective in food vacuole formation, MS-1, blocked in secretion of lysosomal enzymes, and SB 281, defective in mucocyst maturation. Immunoelectron microscopy and confocal laser scanning microscopy demonstrated that Tetrahymena HPPD primarily localized to membranes of the endoplasmic reticulum. In addition, Tetrahymena HPPD was detected in association with membranes of the Golgi apparatus, and transport vesicles in exponentially growing wild-type and mutant strains. In starved cells, Tetrahymena HPPD localized exclusively to membranes of small vesicles. Since no de novo synthesis of Tetrahymena HPPD takes place in cells starved for more than 30 min, these results suggest that there is a flow of Tetrahymena HPPD from the endoplasmic reticulum to small vesicles, possibly via the Golgi apparatus, and that Tetrahymena HPPD contains a signal for vesicle membrane retrieval or retention.
U2 - 10.1006/cbir.1998.0336
DO - 10.1006/cbir.1998.0336
M3 - Journal article
C2 - 10736196
SN - 1065-6995
VL - 23
SP - 719
EP - 728
JO - Cell Biology International
JF - Cell Biology International
IS - 11
ER -