ライフサイエンスコーパス: FAPy

1 ylamino-4(3H)-pyrimidinone 5'-monophosphate (FAPy).

2 ibosylamino-4(3H)-pyrimidinone 5'-phosphate (FAPy).

3 mino-4-hydroxy-5N-methylformamidopyrimidine (FaPy-7-MeGua), and abasic sites but not DNA substrates c

4 in duplex DNA the AFB moiety of the AFB-beta-FAPY adduct also intercalates on the 5' side of the pyri

5 The AFB-alpha-FAPY adduct blocks replication; it destabilizes the DNA

6 acking interactions induced by the AFB-alpha-FAPY adduct explain its lower stability as compared to t

7 Acid hydrolysis of the FAPY adduct gives the FAPY base which exists in two sepa

8 Herein, the structure of the AFB-alpha-FAPY adduct has been elucidated in 5'-d(C(1)T(2)A(3)T(4)

9 lower stability as compared to the AFB-beta-FAPY adduct in duplex DNA.

10 calation of the AFB moiety for the AFB-alpha-FAPY adduct in the tetramer 5'-d(C(1)T(2)X(3)A(4))-3', i

11 The FAPY adduct may be a major progenitor of aflatoxin B1-in

12 ken together, these characteristics make the FAPY adduct the prime candidate for both the genotoxicit

13 ide moiety is also observed for the AFB-beta-FAPY adduct, and suggests that the identity of the 3'-ne

14 The structure of a formamidopyrimidine (FAPY) adduct arising from imidazole ring opening of the

15 ive a highly persistent formamidopyrimidine (FAPY) adduct which exists as a mixture of forms.

16 rolyzes to form the formamidopyrimidine (AFB-FAPY) adduct, which interconverts between alpha and beta

17 te and an AFB(1)-formamidopyrimidine (AFB(1)-FAPY) adduct.

18 type and supports conversion of GTP to both FAPy and APy.

19 imidazole ring opening [formamidopyrimidine (Fapy)] and is associated with significant myelosuppressi

20 ibosylamino-4(3H)-pyrimidinone 5'-phosphate (FAPy), as shown by UV-visible spectrophotometry, mass sp

21 orientation shifts to become parallel to the FAPY base and displaced toward the minor groove.

22 Acid hydrolysis of the FAPY adduct gives the FAPY base which exists in two separable but interconvert

23 NMR studies carried out on the AFB-FAPY bases and deoxynucleoside 3',5'-dibutyrates now est

24 dibutyrates now establish that the separable FAPY bases and nucleosides are diastereomeric N5 formyl

25 involving the R(a) axial conformation of the FAPY C5-N(5) bond and the E conformation of the formamid

26 pairs T(4).A(17) and X(5).C(16), placing the FAPY C5-N(5) bond in the R(a) axial conformation.

27 idopyrimidine nucleoside repair by examining Fapy*dA and Fapy*dG excision opposite all four native 2'

28 Fapy*dA is removed more rapidly than Fapy*dG, and duplex

29 tected from formamidopyrimidine nucleosides (Fapy*dA, Fapy*dG) via a pathway distinct from the Escher

30 st chemical syntheses of a monomeric form of Fapy-dA (1) and oligonucleotides containing this lesion

31 These results indicate that Fapy-dA and Fapy-dG will be sufficiently long-lived in D

32 es that the half-life for deglycosylation of Fapy-dA at 37 degrees C is approximately 103 h.

33 y 25 times more resistant to hydrolysis than Fapy-dA at 55 degrees C.

34 Deglycosylation of Fapy-dA in the monomer follows first-order kinetics from

35 The rate constants for deglycosylation of Fapy-dA in the monomeric and oligonucleotide substrates

36 Monomeric Fapy-dA readily epimerized at 25 degrees C in phosphate

37 containing the beta-C-nucleoside analogue of Fapy.dA (beta-C-Fapy.dA) opposite all native nucleotides

38 Fpg efficiently excises Fapy.dA (K(m) = 1.2 nM, k(cat) = 0.12 min(-1)) opposite

39 ding lesions derived from 2'-deoxyadenosine, Fapy.dA and 8-oxo-dA, were not detectably mutagenic in t

40 The formamidopyrimidines Fapy.dA and Fapy.dG are produced in DNA as a result of o

41 as a tool to determine the configuration of Fapy.dA and Fapy.dG in DNA.

42 hibitor (K(I) = 3.5 +/- 0.3 nM) of repair of Fapy.dA by Fpg, suggesting the C-nucleoside may have use

43 These data suggest that Fapy.dA could be deleterious to the genome.

44 Incision of alpha-C-Fapy.dA follows Michaelis-Menten kinetics (K(m) = 144.0

45 Fapy.dA incision is considerably slower than that of alp

46 The extent of Fapy.dA incision suggests that the lesion exists predomi

47 Fapy.dA is produced in DNA as a result of oxidative stre

48 ng formamidopyrimidine lesions indicate that Fapy.dA is readily identified as an alkali-labile lesion

49 a higher frequency than 8-oxo-G-->T and that Fapy.dA is very weakly mutagenic, as is 8-oxo-dA.

50 ple turnovers are observed for the repair of Fapy.dA mispairs in a short period of time, indicating t

51 The interaction of DNA containing Fapy.dA or nonhydrolyzable analogues with Fpg and MutY i

52 Endo IV incision of Fapy.dA proceeds further upon rehybridization, suggestin

53 rachromosomal probes containing a Fapy.dG or Fapy.dA site-specifically incorporated, which showed une

54 IV incision of the C-nucleoside analogues of Fapy.dA was used to establish selectivity for the alpha-

55 e diastereomers of C-nucleoside analogues of Fapy.dA were introduced by using the respective phosphor

56 MutY also does not incise Fapy.dA when the lesion is opposite dG.

57 eta-C-nucleoside analogue of Fapy.dA (beta-C-Fapy.dA) opposite all native nucleotides (K(D) < 27 nM),

58 , as well as the alpha-C-nucleoside (alpha-C-Fapy.dA) opposite dC (K(D) = 7.1 +/- 1.5 nM).

59 is considerably slower than that of alpha-C-Fapy.dA, and does not proceed to completion.

60 a duplex containing this nucleotide opposite Fapy.dA, nor does it exhibit an increased level of bindi

61 All duplexes containing Fapy.dA-dX or its C-nucleoside analogue melt lower than

62 entially cleaves duplex DNA containing alpha-Fapy.dA.

63 oved as efficiently from duplexes containing Fapy.dA:dA or Fapy.dA:dG base pairs.

64 ently from duplexes containing Fapy.dA:dA or Fapy.dA:dG base pairs.

65 A duplex containing a beta-C-Fapy.dA:T base pair is an effective inhibitor (K(I) = 3.

66 e nucleoside repair by examining Fapy*dA and Fapy*dG excision opposite all four native 2'-deoxyribonu

67 om formamidopyrimidine nucleosides (Fapy*dA, Fapy*dG) via a pathway distinct from the Escherichia col

68 Fapy*dA is removed more rapidly than Fapy*dG, and duplexes containing purine nucleotides oppo

69 (pol zeta) to incorporate an A opposite AFB1-Fapy-dG and extend from this mismatch, biological eviden

70 godeoxynucleotide d(GCGTACXCATGCG) harboring Fapy-dG as the central residue and developing a protocol

71 d oligonucleotides containing this lesion or Fapy-dG at a defined site.

72 In COS7 cells, NM-Fapy-dG caused targeted mutations, predominantly G --> T

73 of the rate constant for deglycosylation of Fapy-dG in an oligonucleotide, revealed that this lesion

74 Although formation of NM-Fapy-dG in cellular DNA has been demonstrated, its poten

75 significant increases in the levels of AFB1-Fapy-dG in Neil1(-/-) vs. wild-type liver DNA.

76 NMR assignment of the Fapy-dG lesion (X) embedded within a TXT trimer reveals

77 Following deprotection and isolation, the Fapy-dG lesion is generated by catalytic hydrogenation a

78 el synthetic strategy to incorporate cognate Fapy-dG site-specifically within any oligodeoxynucleotid

79 These results indicate that Fapy-dA and Fapy-dG will be sufficiently long-lived in DNA so as to

80 -diamino-4-hydroxy-5-formyl amidopyrimidine (Fapy-dG), is associated with progression of age-related

81 N(5)-NM-substituted formamidopyrimidine (NM-Fapy-dG).

82 ring-opened AFB1-deoxyguanosine adduct (AFB1-Fapy-dG).

83 ning yielding formamidopyrimidine AFB1 (AFB1-Fapy-dG).

84 uld catalyze high-fidelity synthesis past NM-Fapy-dG, but only on a template subpopulation, presumabl

85 To elucidate the mechanisms of bypass of NM-Fapy-dG, we performed replication assays in vitro with a

86 he alpha-anomer as a major contributor to NM-Fapy-dG-induced mutagenesis in primate cells.

87 tary d(CGCATGCGTACGC) counterpart yields two Fapy-dG.C duplexes that are differentially destabilized

88 Fpg excises Fapy.dG (K(M) = 2.0 nM, k(cat) = 0.14 min(-1)) opposite

89 Fapy.dG (N(6)()-(2-deoxy-alpha,beta-d-erythropentofurano

90 Fapy.dG and 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxo-d

91 The similar effects of Fapy.dG and 8-oxodG on DNA polymerase and repair enzymes

92 a low dA misincorporation frequency opposite Fapy.dG and inefficient extension of a Fapy.dG:dA base p

93 Recently, Fapy.dG and its C-nucleoside analogue were incorporated

94 Bypass efficiency of Fapy.dG and OxodG increased modestly in SOS-induced cell

95 MutY incises dA when it is opposite Fapy.dG and strongly binds duplexes containing the lesio

96 The formamidopyrimidines Fapy.dA and Fapy.dG are produced in DNA as a result of oxidative str

97 --> T transversion frequencies observed upon Fapy.dG bypass were <or=1.9% in wild-type E. coli.

98 These data demonstrate that Fapy.dG closely resembles the interactions of 8-oxodG wi

99 Fapy.dG containing dinucleotide phosphoramidites contain

100 , polymerase-mediated introduction of beta-C-Fapy.dG could be useful for incorporating useful amounts

101 es in vitro raise the question as to whether Fapy.dG elicits similar effects in vivo.

102 Bypass of Fapy.dG in a shuttle vector in COS-7 cells produces G --

103 o determine the configuration of Fapy.dA and Fapy.dG in DNA.

104 Like 8-oxodG, Fapy.dG instructs DNA polymerase to misincorporate dA op

105 Overall, these experiments suggest that Fapy.dG is at most weakly mutagenic in E. coli.

106 Under some conditions Fapy.dG is formed in greater yields than 8-oxodG from a

107 iperidine (1.0 M, 90 degrees C, 20 min), but Fapy.dG is less easily identified in this manner.

108 r in simian kidney (COS-7) cells showed that Fapy.dG is mutagenic inducing primarily targeted Fapy.G-

109 Fapy.dG is produced in DNA as a result of oxidative stre

110 Fapy.dG is produced in DNA as a result of oxidative stre

111 In contrast to OxodG bypass, Fapy.dG mutation frequencies were unaffected by carrying

112 incorporation could account for the level of Fapy.dG observed in cells if 1% of the dGTP pool is conv

113 The effect of Fapy.dG on replication in Escherichia coli was studied b

114 n using extrachromosomal probes containing a Fapy.dG or Fapy.dA site-specifically incorporated, which

115 ations observed above background when either Fapy.dG or OxodG was bypassed.

116 The interactions of DNA containing Fapy.dG or the nonhydrolyzable analogue with Fpg and Mut

117 Endo IV incises Fapy.dG to less than 5% under comparable reaction condit

118 for synthesizing oligonucleotides containing Fapy.dG utilized a reverse dinucleotide phosphoramidite,

119 the 5'-TGT sequence mutational frequency of Fapy.dG was approximately 30%, whereas in the 5'-TGA seq

120 Fapy.dG was bypassed less efficiently than OxodG.

121 was found to be slightly less mutagenic than Fapy.dG, though it also exhibited a similar context effe

122 for synthesizing oligonucleotides containing Fapy.dG, which does not require reverse phosphoramidites

123 However, duplexes containing Fapy.dG-dA mispairs melt significantly higher than those

124 nds duplexes containing the lesion or beta-C-Fapy.dG.

125 Incision from Fapy.dG.dA is faster than from dG.dA mispairs but slower

126 ind duplexes containing Fapy.dG.dC or beta-C-Fapy.dG.dC compared to those in which the lesion is oppo

127 Fpg also prefers to bind duplexes containing Fapy.dG.dC or beta-C-Fapy.dG.dC compared to those in whi

128 osite Fapy.dG and inefficient extension of a Fapy.dG:dA base pair work synergistically to minimize th

129 polymerase I from Escherichia coli accepted Fapy.dGTP and beta-C-Fapy.dGTP as substrates much less e

130 ses is enhanced by inefficient hydrolysis of Fapy.dGTP and beta-C-Fapy.dGTP by MutT, the E. coli enzy

131 cherichia coli accepted Fapy.dGTP and beta-C-Fapy.dGTP as substrates much less efficiently than it di

132 efficient hydrolysis of Fapy.dGTP and beta-C-Fapy.dGTP by MutT, the E. coli enzyme that releases pyro

133 ,6-diamino-4-hydroxy-5-f ormamidopyrimidine (Fapy.dGTP) and its C-nucleoside analogue (beta-C-Fapy.dG

134 .dGTP) and its C-nucleoside analogue (beta-C-Fapy.dGTP) were synthesized.

135 cells if 1% of the dGTP pool is converted to Fapy.dGTP.

136 n 3-methyladenine DNA glycosylases I and II, FAPY DNA glycosylase, both known apurinic/apyrimidinic e

137 ichia coli, Fapy lesions are repaired by the Fapy-DNA glycosylase (Fpg) protein.

138 FAPY formation resulted in the loss of the guanine H8 pr

139 The FAPY formyl group was positioned to form a hydrogen bond

140 ed unequivocally that in simian kidney cells Fapy.G-->T substitutions occur at a higher frequency tha

141 .dG is mutagenic inducing primarily targeted Fapy.G-->T transversions.

142 Similarly, syn-Fapy.G:dATP pairing showed greater stacking in the 5'-TG

143 the 5'-TGA sequence, while stacking for anti-Fapy.G:dCTP pairs was similar in the two sequences.

144 Both Escherichia coli fapy glycosylase (Fpg) and human 8-oxo-DNA glycosylase (

145 ibosylamino-4(3H)-pyrimidinone 5'-phosphate (FAPy), has been shown to require Mg2+ for catalytic acti

146 Gua, and (ii) one proposed rotamer of AFB(1)-FAPY is a block to replication, even when the efficient

147 AFB(1)-FAPY is detected at near maximal levels in rat DNA days

148 In Escherichia coli, Fapy lesions are repaired by the Fapy-DNA glycosylase (F

149 ucts allowed us to investigate the repair of Fapy lesions in nuclear and mitochondrial extracts from

150 Fapy lesions inhibit DNA synthesis likely modulating the

151 or exacerbating the mutagenic properties of Fapy lesions, their excision by three glycosylases, Fpg,

152 putatively nonmutagenic formamidopyrimidine (Fapy) lesions of adenine (Ade) and guanine (Gua) to eluc

153 putatively nonmutagenic formamidopyrimidine (Fapy) lesions.

154 events that permit GCH II to produce either FAPy or APy.

155 n became important when one of the two major FAPY species in DNA was found to be potently mutagenic a

156 In oligodeoxynucleotides, two equilibrating FAPY species, separable by HPLC, are assigned as anomers

157 C(16)A(17)T(18)A(19)G(20))-3' (X = AFB-alpha-FAPY) using molecular dynamics calculations restrained b

158 ng properties of this DNA adduct: (i) AFB(1)-FAPY was found to cause a G to T mutation frequency in E