ライフサイエンスコーパス: VKOR

1 VKOR and its homologues generate disulphide bonds in org

2 VKOR is an integral membrane protein that reduces vitami

3 VKOR is subsequently reactivated by an unknown redox pro

4 VKOR is therefore an ancient gene/protein that can be st

5 mutated to alanine (C43A/C51A), as well as a VKOR with residues C43-C51 deleted.

6 rane proteins demonstrate the existence of a VKOR enzyme complex where PDI and VKORC1 appear to be ti

7 ded Cys132-Cys135 disulfide bond to activate VKOR.

8 tiple Cys residues, we propose that MdbA and VKOR constitute a major folding machine for the secretom

9 we propose a hetero-dimeric form of VKC and VKOR that may explain the efficient oxidation and reduct

10 the two integral-membrane proteins, VKC and VKOR, maintain vitamin K levels and sustain the blood co

11 on prior biochemical experiments on VKC and VKOR, we propose a hetero-dimeric form of VKC and VKOR t

12 report two crystal structures of a bacterial VKOR captured in different reaction states.

13 The bacterial VKOR homolog may represent a target for antibiotics and

14 molecular electron transfer in the bacterial VKOR homologue, are not required for human VKOR whether

15 en VKOR assay, all mutations exhibited basal VKOR activity and warfarin IC50 values that correspond w

16 tructural and functional differences between VKOR and VKORL shown here indicate that VKORL might have

17 duced vitamin K(1) cofactor transfer between VKOR and gamma-carboxylase is shown to be significantly

18 Finally, our results show that although both VKOR and VKORL form disulfide-linked oligomers, the cyst

19 reduced vitamin K(1) cofactor production by VKOR in the system where VKOR is the rate-limiting step

20 ing intact membranes from cells coexpressing VKOR and carboxylase.

21 135), which become oxidized with concomitant VKOR inactivation.

22 yl carboxylation also exhibited differential VKOR inhibition by warfarin enantiomers (S > R) consiste

23 unctionally substituted with dithiothreitol, VKOR overexpression increased the fIX carboxylation rate

24 st to results from the dithiothreitol-driven VKOR assay, all mutations exhibited basal VKOR activity

25 onfirmed that MGC11276 messenger RNA encodes VKOR through its expression in insect cells and sensitiv

26 siological function of its paralogous enzyme VKOR-like (VKORL) is yet unknown.

27 dizing equivalents to the ER: Ero1alphabeta, VKOR, PRDX4, or QSOX1.

28 These findings establish VKOR as a significant contributor to disulfide bond form

29 the active site is maintained to facilitate VKOR catalysis.

30 we report the identification of the gene for VKOR based on specific inhibition of VKOR activity by a

31 (TMD) topology models have been proposed for VKOR.

32 ast 20 years that cysteines are required for VKOR function.

33 We propose a pathway for how VKOR uses electrons from cysteines of newly synthesized

34 stem was designed and used to understand how VKOR and gamma-carboxylase work together as a system and

35 However, VKOR contains evolutionarily conserved Cys residues (Cys

36 l VKOR homologue, are not required for human VKOR whether they are located in the cytoplasm (three-TM

37 nes apparently play different roles in human VKOR and in its bacterial homologues.

38 Interestingly, human VKOR can be changed to a four-TMD molecule by mutating t

39 x reaction, Cys43 in a luminal loop of human VKOR forms a transient disulfide bond with a thioredoxin

40 cent protein to the N or C terminus of human VKOR, expressed these fusions in HEK293 cells, and exami

41 ics and a model for genetic studies of human VKOR.

42 together, our results demonstrate that human VKOR employs the same electron transfer pathway as its b

43 Here, we demonstrate that human VKOR has the same membrane topology as the enzyme from S

44 Our results confirm that human VKOR is a three-TMD protein.

45 form this specific disulfide bond with human VKOR.

46 a 12-aa tag, was used to purify and identify VKOR.

47 To identify VKOR, we used 4'-azido-warfarin-3H-alcohol as an affinit

48 en hampered by the difficulty of identifying VKOR involved in warfarin sensitive reduction of vitamin

49 ting the existence of a CXXC redox center in VKOR.

50 e, we mutated each of the seven cysteines in VKOR.

51 ed as the potential transmembrane domains in VKOR can individually insert across the endoplasmic reti

52 However, a similar mutation in VKOR does not affect its enzymatic activity.

53 Therefore, the involvement of VKORC1L1 in VKOR activity partly explains the low susceptibility of

54 kDa recombinant protein was found to inhibit VKOR activity and to protect the enzyme from warfarin in

55 idual genes to test their ability to inhibit VKOR activity in human cells.

56 ng of VKORC1, a proposed subunit of a larger VKOR enzyme complex, have provided opportunities for new

57 of N-linked glycosylation-tagged full-length VKOR shows that the N terminus of VKOR is located in the

58 ect cells expressing HPC4-tagged full-length VKOR.

59 In addition, we made VKOR with both C43 and C51 mutated to alanine (C43A/C51A

60 lications for the mechanism of the mammalian VKOR and explain how mutations can cause resistance to t

61 testing the ability of wild type and mutant VKORs to support carboxylation, using intact membranes f

62 arfarin-resistant mutations of mycobacterial VKOR appear in similar locations to mutations found in h

63 ere significantly smaller than the amount of VKOR overexpression (15-fold).

64 The characterization of VKOR activity in extrahepatic tissues demonstrated that

65 ation will allow further characterization of VKOR in relation to other components of the vitamin K cy

66 The catalytic core of VKOR is a four transmembrane helix bundle that surrounds

67 Deletion of VKOR results in a severe growth defect in mycobacteria,

68 These data indicate that the effect of VKOR overexpression is limited in vivo, possibly because

69 , which are rescued by ectopic expression of VKOR, but not a mutant containing an alanine substitutio

70 It is proposed that formation of VKOR in the endoplasmic reticulum membrane resembles for

71 K to KH(2), and (4) the primary function of VKOR is the reduction of KO to vitamin K.

72 Bacterial homologs of VKOR were recently found to participate in a pathway lea

73 rystal structure of a bacterial homologue of VKOR from Synechococcus sp.

74 ene for VKOR based on specific inhibition of VKOR activity by a single siRNA pool.

75 VKOR in the membrane, and the interaction of VKOR with the carboxylase.

76 Localization of VKOR to 190 genes within human chromosome 16p12-q21 narr

77 Here, to better understand the mechanism of VKOR catalysis, we report two crystal structures of a ba

78 cond TM domain in the proposed 4-TM model of VKOR does not function as an authentic TM helix; support

79 rther evidence for this topological model of VKOR was obtained with freshly prepared intact microsome

80 Both results support a three-TMD model of VKOR.

81 The physiological redox partner of VKOR remains uncertain, but is likely a thioredoxin-like

82 We screened for redox partners of VKOR among the large number of mammalian Trx-like ER pro

83 added to a partially purified preparation of VKOR, two proteins were identified by mass spectrometry

84 illustrates the ease and reproducibility of VKOR purification by the method reported in our recent p

85 hort helix at the hydrophobic active site of VKOR that alters between wound and unwound conformations

86 , the gene encoding the catalytic subunit of VKOR was identified as a 163-amino acid integral membran

87 ull-length VKOR shows that the N terminus of VKOR is located in the endoplasmic reticulum lumen, and

88 Our results show that the N terminus of VKOR resides in the ER lumen, whereas its C terminus is

89 nism of warfarin resistance, the topology of VKOR in the membrane, and the interaction of VKOR with t

90 sequence homology, the membrane topology of VKOR is still in debate.

91 experimentally derived membrane topology of VKOR.

92 ies provide a comprehensive understanding of VKOR function.

93 Of importance, Ero1, PRDX4, or VKOR was individually capable of supporting cell viabili

94 min K generated by vitamin K oxidoreductase (VKOR) and a redox protein that regenerates VKOR activity

95 The vitamin K oxidoreductase (VKOR) reduces vitamin K to support the carboxylation and

96 Partially purified VKOR from resistant and normal rat livers showed no diff

97 Purified recombinant VKOR with tag is approximately 21 kDa, as expected; full

98 nd involves vitamin K 2,3-epoxide reductase (VKOR) activity.

99 itol-driven vitamin K 2,3-epoxide reductase (VKOR) assay has not reflected clinical resistance phenot

100 umarins inhibit vitamin K epoxide reductase (VKOR) by depleting reduced vitamin K that is required fo

101 Vitamin K epoxide reductase (VKOR) catalyzes the conversion of vitamin K 2,3-epoxide

102 ntial role of a vitamin K epoxide reductase (VKOR) gene in pilus assembly.

103 Vitamin K epoxide reductase (VKOR) generates vitamin K hydroquinone to sustain gamma-

104 C9 (CYP2C9) and vitamin K epoxide reductase (VKOR) genes have been shown to have a significant effect

105 Vitamin K epoxide reductase (VKOR) is an essential enzyme for vitamin K-dependent car

106 Vitamin K epoxide reductase (VKOR) is essential for the production of reduced vitamin

107 Vitamin K epoxide reductase (VKOR) is the target of warfarin, the most widely prescri

108 Subsequently, vitamin K epoxide reductase (VKOR) is thought to convert the alkoxide-epoxide to a hy

109 ensitive enzyme vitamin K epoxide reductase (VKOR) of the cycle reduces vitamin K 2,3-epoxide to the

110 tive enzyme vitamin K 2,3-epoxide reductase (VKOR) of the vitamin K cycle that has been shown to harb

111 e intramembrane vitamin K epoxide reductase (VKOR) supports blood coagulation in humans and is the ta

112 Vitamin K epoxide reductase (VKOR) sustains blood coagulation by reducing vitamin K e

113 farin's target, vitamin K epoxide reductase (VKOR), has resisted purification since its identificatio

114 rin targets vitamin K 2,3-epoxide reductase (VKOR), the enzyme that produces reduced vitamin K, a req

115 the activity of vitamin K epoxide reductase (VKOR), the target of the anticoagulant warfarin (Coumadi

116 e enzyme vitamin K(1) 2,3-epoxide reductase (VKOR), which provides gamma-carboxylase with reduced vit

117 transfected and vitamin K epoxide reductase (VKOR)-transfected cells, the simplest explanation for th

118 oxylase and vitamin K 2,3-epoxide reductase (VKOR).

119 insensitive vitamin K 2,3-epoxide reductase (VKOR).

120 e 1 (QSOX1) and vitamin K epoxide reductase (VKOR).

121 farin-resistant vitamin K epoxide reductase (VKOR-Y139F) supported carboxylation in HEK293 cells when

122 Vitamin K epoxide (or oxido) reductase (VKOR) is the target of warfarin and provides vitamin K h

123 (VKOR) and a redox protein that regenerates VKOR activity.

124 ion test system where the warfarin-sensitive VKOR produces the cofactor for the gamma-carboxylase.

125 The structure shows VKOR in complex with its naturally fused redox partner,

126 unction as an authentic TM helix; supporting VKOR is a 3-TM protein, which is different from VKORL.

127 to be a warfarin-sensitive enzyme other than VKOR that reduces vitamin K to KH(2), and (4) the primar

128 By alkylation assays, we demonstrate that VKOR is required for MdbA reoxidation.

129 simplest explanation for this result is that VKOR catalyzes both the reduction of vitamin K epoxide t

130 It has been reported that VKOR is a multisubunit enzyme.

131 Our results show that VKOR interacts strongly with TMX, an ER membrane-anchore

132 The results show that VKOR is the rate-limiting step in the gamma-carboxylatio

133 Altogether, our results suggest that VKOR is a type III membrane protein with three transmemb

134 r pathway as its bacterial homologs and that VKORs generally prefer membrane-bound Trx-like redox par

135 atic tissues demonstrated that a part of the VKOR activity, more or less important according to the t

136 nsferase gene family as one component of the VKOR enzyme complex in the endoplasmic reticulum membran

137 the sequence of the 18-kDa subunit 1 of the VKOR enzyme complex was found to be identical in the two

138 ase activity coincided with formation of the VKOR enzyme complex.

139 Identification of the VKOR gene extends our understanding of blood clotting, a

140 Here we show that the VKOR homolog from the bacterium Mycobacterium tuberculos

141 in how mutations can cause resistance to the VKOR inhibitor warfarin, the most commonly used oral ant

142 ith Ero1 that PRDX4 and, for the first time, VKOR contribute to ER oxidation and that depletion of al

143 r stronger inhibitors of the M. tuberculosis VKOR homolog.

144 Both reductants resulted in wild type VKOR reduction of vitamin K epoxide; however, the C43A a

145 actor production by VKOR in the system where VKOR is the rate-limiting step for gamma-carboxylation.

146 ity of the gamma-carboxylation system, where VKOR provides the reduced vitamin K(1)H(2) cofactor, was