Role of thymidine phosphorylase activity in the angiogenic effect of platelet derived endothelial cell growth factor/thymidine phosphorylase.
Human thymidine phosphorylase (dThdPase) has been reported to be identical with the platelet-derived endothelial cell growth factor (PD-ECGF). To investigate whether the dThdPase activity of PD-ECGF/dThdPase is indispensable to its angiogenic activity, three PD-ECGF/dThdPase mutants, K115E (Lys-115-->Glu), L148R (Leu-148-->Arg) and R202S (Arg-202-->Ser) were made by site-directed mutagenesis. Although the expression level of the three mutant PD-ECGF/dThdPases in the COS-7 cells was similar to that of wild-type PD-ECGF/dThdPase, dThdPase activity was not detected in the COS-7 cells transfected with the mutant PD-ECGF/dThdPase cDNA. The lysates of COS-7 cells transfected with the wild-type PD-ECGF/dThdPase cDNA had angiogenic activity, but those transfected with the mutant PD-ECGF/dThdPase cDNAs did not. An inhibitor of dThdPase, 6-amino-5-chlorouracil, inhibited the angiogenic activity of purified dThdPase. These findings indicate that dThdPase activity is indispensable to the angiogenic activity of PD-ECGF/dThdPase.
Miyadera
K
K
Department of Cancer Chemotherapy, Kagoshima University, Japan.
Sumizawa
T
T
Haraguchi
M
M
Yoshida
H
H
Konstanty
W
W
Yamada
Y
Y
Akiyama
S
S
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D001792:Blood Platelets / Q000502:physiology; D002460:Cell Line; D002522:Chlorocebus aethiops; D017931:DNA Primers; D016228:Endothelial Growth Factors / Q000096:biosynthesis / Q000378:metabolism*; D015870:Gene Expression; D006454:Hemoglobins / Q000378:metabolism; D006801:Humans; D007668:Kidney; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D009389:Neovascularization, Pathologic; D009838:Oligodeoxyribonucleotides; D017354:Point Mutation; D016133:Polymerase Chain Reaction; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000378:metabolism; D013939:Thymidine Phosphorylase / Q000096:biosynthesis / Q000378:metabolism*
D017931:DNA Primers; D016228:Endothelial Growth Factors; D006454:Hemoglobins; D009838:Oligodeoxyribonucleotides; D011994:Recombinant Proteins; D013939:Thymidine Phosphorylase