ライフサイエンスコーパス: MEKK2

1 en-activated protein kinase kinase kinase 2 (MEKK2).

2 the human counterpart of the reported murine MEKK2.

3 not bind MEKK3, which is closely related to MEKK2.

4 -immunoprecipitated and PRK2 is activated by MEKK2.

5 BMK1)/ERK5 pathway, as a binding partner for MEKK2.

6 was performed to identify proteins that bind MEKK2.

7 sely related kinase PRK1, which did not bind MEKK2.

8 ll adapter protein, as a binding partner for MEKK2.

9 ylation and activation of a key MAP3 kinase, MEKK2.

10 lioblastoma, including PTEN, RB1, and MAP3K2/MEKK2.

11 at it heterodimerizes with the PB1 domain of MEKK2.

12 tors, Smads, transcription factors, RhoA and MEKK2.

13 promotes the ubiquitination and turnover of MEKK2.

14 nase 5, and AP-1 reporter gene activation by MEKK2.

15 s than the phosphorylated and, hence, active MEKK2.

16 complex with inactive and nonphosphorylated MEKK2.

17 Kinase-inactive MEKK1, but not MEKK2, 3 or 4, strongly inhibited EGF-stimulated ERK act

18 MEKK1, but not MEKK2, -3 or -4, is a caspase-3 substrate that when clea

19 tudy reveals a novel molecular mechanism for MEKK2/3 activation by the TLR and cellular stress pathwa

20 this serine to an alanine severely impaired MEKK2/3 activation.

21 We generated an anti-p-MEKK2/3 antibody and used this antibody to demonstrate t

22 1 in the ERK5 MAP kinase pathway upstream of MEKK2/3.

23 We show that MEK kinase 2 (MEKK2), a MAPK kinase kinase (MAP3K) that regulates the

24 ing adaptor protein that binds MEK kinase 2 (MEKK2), a mitogen-activated protein kinase (MAPK) kinase

25 d activates Rap1, a small GTPase, as well as MEKK2, a MEK5 kinase.

26 Activation of MEKK2, a mitogen-activated protein (MAP) kinase kinase k

27 Importantly, disrupted expression of MEKK2, a related MAPK kinase kinase, had no effect on uP

28 ssion of constitutively active MPK4 restored MEKK2 abundance to wild-type levels in mekk1 mutant plan

29 Compared with MEKK3, MEKK2 activated BMK1/ERK5 to a greater extent, which mig

30 Similarly, purified recombinant MEKK2 activated PRK2 in vitro.

31 We describe an alternative pathway by which MEKK2 activates MEK5 and big MAP kinase1/extracellular s

32 In particular, Mip1 prevented MEKK2 activation by blocking MEKK2 dimer formation, whic

33 MEKK2 activation of PRK2 is independent of MEKK2 regulat

34 MEKK2 activation of PRK2 results in a bifurcation of sig

35 In this study, we demonstrated that MAP3K MEKK2 activation requires dimerization.

36 iescent MEKK2 preferentially binds MEK5, and MEKK2 activation results in ERK5 activation.

37 ion is an important regulatory mechanism for MEKK2 activation.

38 This mekk2 allele can rescue the mpk4 autoimmune phenotype in

39 MEKK2 also synergized with anti-CD3 antibody to activate

40 WNK1 phosphorylated both MEKK2 and -3 in vitro, and MEKK3 was activated by WNK1 i

41 MAPKKK/MEKK level protein kinases from mouse MEKK2 and -3, Drosophila melanogaster PK92B, Saccharomyc

42 In contrast to MEKK2 and 3, MEKK1 and 4 specifically associated with Ra

43 and in post-Golgi vesicular-like structures; MEKK2 and 4 were localized to distinct Golgi-associated

44 , it leads to accumulation of phosphorylated MEKK2 and activation of the downstream JNK signaling cas

45 e distinct MEK5 PB1 domain binding sites for MEKK2 and ERK5, with a C-terminal extension of the PB1 d

46 in inhibition of Src-dependent activation of MEKK2 and ERK5.

47 xpression and by blocking the interaction of MEKK2 and Lad.

48 MEKK2 and Lad/RIBP colocalize at the T cell contact site

49 ting cells, demonstrating cotranslocation of MEKK2 and Lad/RIBP during T cell activation.

50 MEKK2 and MEK5 encode Phox/Bem1p (PB1) domains that hete

51 Furthermore, co-immunoprecipitation of MEKK2 and MEK5 from cell lysates shows that they form a

52 y complex through interactions involving the MEKK2 and MEK5 PB1 domains and a 34-amino-acid C-termina

53 The findings define how the MEKK2 and MEK5 PB1 domains are uniquely used for differe

54 Expression of dominant negative mutants of MEKK2 and MEKK3 also blocked activation of ERK5 by WNK1.

55 MEKK2 and MEKK3 are differentially associated with signa

56 MEKK2 and MEKK3 are MAPK kinase kinases that activate th

57 The kinase domains of MEKK2 and MEKK3 are nearly identical, although their N-t

58 MEKK2 and MEKK3 are two closely related mitogen-activate

59 The PB1 domains of MEKK2 and MEKK3 bind the PB1 domain of MEK5 but do not s

60 We now show that MEKK2 and MEKK3 can in vivo activate IKK-alpha and IKK-b

61 Moreover, both MEKK2 and MEKK3 coimmunoprecipitated with endogenous WNK

62 to identify mutations in the closely linked MEKK2 and MEKK3 loci.

63 g the specific and unique requirement of the MEKK2 and MEKK3 PB1 domain in regulating ERK5 activation

64 demonstrate that lipopolysaccharide induced MEKK2 and MEKK3 phosphorylation on their regulatory seri

65 t the PB1 domain mediates the association of MEKK2 and MEKK3 with MEK5 and that the respective PB1 do

66 gen-activated protein kinase kinase kinases, MEKK2 and MEKK3, and this interaction may in part be med

67 on site, serine 519 and serine 526, in MAP3K MEKK2 and MEKK3, respectively.

68 Unlike MEKK2 and MEKK3, the C-terminal kinase domain of MEKK1 d

69 er of a tandemly duplicated gene family with MEKK2 and MEKK3.

70 inhibiting both tumor growth and metastasis; MEKK2 and MLK3 represent untargeted kinases in tumor bio

71 Knockdown of MEKK2 and MLK3 resulted in increased apoptosis in orthot

72 The screen identified two MAP3Ks, MEKK2 and MLK3, whose shRNA knockdown caused significant

73 In cells, MEKK2 and PRK2 are co-immunoprecipitated and PRK2 is act

74 strate that Smurf1 physically interacts with MEKK2 and promotes the ubiquitination and turnover of ME

75 We obtained five mutations in MEKK2 and seven mutations in MEKK3, all located within 2

76 Activation of MEKK2 and the ERK5 pathway by EGF and stress stimuli is

77 amino acids 228 to 282 in the N terminus of MEKK2, and expression of this motif blocks Lad-MEKK2 int

78 lot analysis of FLS demonstrated that MEKK1, MEKK2, and TAK1 were readily detectable and were subsequ

79 tch is recruited to activated MEKK1, but not MEKK2, and this novel scaffolding interaction is depende

80 d protein kinase/ERK kinase kinase (MEKK) 1, MEKK2, apoptosis-signal regulating kinase-1, TGF-beta ac

81 In turn, the abundance of MEKK2 appears to be under cellular surveillance such tha

82 Lad and MEKK2 are in a complex in resting cells.

83 This study identifies Rap1 and MEKK2 as critical upstream signaling molecules mediating

84 Mechanistically, we found that MEKK2 associated with inactive MEKK2 in the absence of 1

85 required for ERK5 activation by Src, Lad and MEKK2 association is required for Src activation of ERK5

86 e ERK5, whereas inhibition of either Rap1 or MEKK2 attenuates BDNF activation of ERK5.

87 Expression of T283A MEKK2 within a MEKK2(-/-) background enhanced stress-activated c-Jun N-

88 The MEKK2 binding site maps to amino acids 637-660 in PRK2,

89 Activated MEKK2 binds and activates MKK7, leading to JNK activatio

90 -3-3 proteins also interacted with MEKK1 and MEKK2, but not MEKK4.

91 The human MEKK2 cDNA encoded a polypeptide of 619 amino acids and

92 onance energy transfer [FRET]) measuring YFP-MEKK2/CFP-MEK5 and CFP-MEK5/YFP-ERK5 interactions define

93 rthermore, we found that the endogenous Mip1-MEKK2 complex was dissociated transiently following epid

94 K2 has a high degree of homology with MEKK3, MEKK2-DD, unlike MEKK3-DD, also fails to restore TNF-alp

95 d to proceed similarly in the bone marrow of Mekk2-deficient and wild-type mice.

96 ajor subsets of thymic and spleen T cells in Mekk2-deficient mice were indistinguishable from those i

97 vity and response to BMP through controlling MEKK2 degradation.

98 that MEKK2 dimer formation in vivo augmented MEKK2-dependent JNK activation and JNK/AP-1 reporter gen

99 ization system, we further demonstrated that MEKK2 dimer formation in vivo augmented MEKK2-dependent

100 Moreover, prevention of MEKK2 dimer formation inhibited MEKK2-mediated JNK activ

101 Mip1 prevented MEKK2 activation by blocking MEKK2 dimer formation, which in turn blocked JNKK2, c-Ju

102 the NH2-terminal region is not required for MEKK2 dimer formation.

103 K2-interacting protein, Mip1, that regulates MEKK2 dimerization and activation by forming a complex w

104 We mapped the MEKK2 dimerization motif in its catalytic domain and sho

105 Here we showed that the MAPK kinase kinases MEKK2 (encoded by Map3k2) and MEKK3 (encoded by Map3k3)

106 MEKK2(-/-) ESMC also lost receptor-mediated stimulation

107 IgE or c-Kit ligand was markedly reduced in MEKK2(-/-) ESMC relative to wild-type ESMC.

108 EGF is similarly inhibited by loss of Lad or MEKK2 expression and by blocking the interaction of MEKK

109 ired for ERK5 activation in response to EGF, MEKK2 expression is required for ERK5 activation by Src,

110 d expression and targeted gene disruption of MEKK2 expression results in loss of epidermal growth fac

111 MEKK2 expression stimulates BMK1/ERK5 activity, the down

112 ufficient because activation of JNK using an MEKK2 expression vector did not mimic the sensitizing ef

113 Biochemical activation of MEKK2 follows TCR stimulation, and expression of a domin

114 found that the inactive, non-phosphorylated MEKK2 formed significantly more dimers than the phosphor

115 inhibited by MAP/ERK kinase (MEK) kinase 2 (MEKK2) gene disruption.

116 Although MEKK2 has a high degree of homology with MEKK3, MEKK2-DD

117 MEKK2 has its kinase domain in the COOH-terminal moiety

118 The NH(2)-terminal moiety of MEKK2 has no signature motif that would suggest a define

119 Furthermore, MEKK2 immunoprecipitates activated c-Jun in an IL-1 depe

120 In vitro kinase assays using MEKK2 immunoprecipitates demonstrated that IL-1 increase

121 -type ESMC, demonstrating the specificity of MEKK2 in signaling cytokine gene regulation.

122 we found that MEKK2 associated with inactive MEKK2 in the absence of 14-3-3 binding, which led to tra

123 at MEK5 is a specific downstream effector of MEKK2 in the BMK1/ERK5 pathway.

124 ation, and expression of a dominant-negative MEKK2 inhibits TCR-mediated conjugate stabilization and

125 MEKK2 integrates stress and mitogenic signals to the act

126 In this study, we identified a novel MEKK2-interacting protein, Mip1, that regulates MEKK2 di

127 KK2, and expression of this motif blocks Lad-MEKK2 interaction, resulting in inhibition of Src-depend

128 aken together, our results showed that human MEKK2 is a key signaling molecule for T-cell receptor/CD

129 MEKK2 is a member of the mitogen-activated protein kinas

130 These data indicate that MEKK2 is a potent activator of the JNK pathway in FLS an

131 on of rapid activation of NF-kappaB, whereas MEKK2 is important in controlling the delayed activation

132 Furthermore, BDNF stimulation of MEKK2 is regulated by Rap1.

133 We have found that MEKK2 is regulated through a phosphorylation-dependent a

134 e to UV irradiation was normal, showing that MEKK2 is required for receptor signaling but not for cel

135 Follow-up genetic analyses indicated that MEKK2 is required for the mekk1, mkk1 mkk2, and mpk4 aut

136 Our data indicate that activation of Rap1 or MEKK2 is sufficient to stimulate ERK5, whereas inhibitio

137 MEKK2 is the first MAP3K shown to be required for mast c

138 MEK kinase 2 (MEKK2) is a 70-kDa protein serine/threonine kinase that

139 maging demonstrate that T cell MEK kinase 2 (MEKK2) is translocated to the T cell/antigen-presenting

140 h it does not reduce the basal expression of MEKK2, it does prevent the upregulation of MEKK2 that is

141 precipitation of, respectively, MEKK2-JNKK2, MEKK2-JNK1, and JNKK2-JNK1, indicating that the interact

142 KK2-JNK1, indicating that the interaction of MEKK2, JNKK2, and JNK1 is synergistic.

143 mation of a tripartite complex consisting of MEKK2, JNKK2, and JNK1.

144 mented the coprecipitation of, respectively, MEKK2-JNKK2, MEKK2-JNK1, and JNKK2-JNK1, indicating that

145 e JNK1 was activated more efficiently in the MEKK2-JNKK2-JNK1 complex than was the JNK1 excluded from

146 a MAPKKK, a MAPKK, and a MAPK molecule like MEKK2-JNKK2-JNK1 is likely to be responsible for the eff

147 No scaffold protein was required for the MEKK2-JNKK2-JNK1 tripartite-complex formation.

148 ted mice carrying a targeted mutation in the Mekk2 locus.

149 MEKK2 (MAP/ERK kinase kinase-2) is a serine/threonine ki

150 n did the wild-type T cells, suggesting that MEKK2 may be involved in controlling the strength of T-c

151 In conclusion, we found that MEKK2 may be required for controlling the strength of TC

152 revention of MEKK2 dimer formation inhibited MEKK2-mediated JNK activation.

153 wn of Mip1 expression by siRNA augmented the MEKK2-mediated JNK and AP-1 reporter activation.

154 recipitates demonstrated that IL-1 increased MEKK2-mediated phosphorylation of the key MAPKKs that ac

155 MEKK2, MEK5, and extracellular signal-regulated kinase 5

156 MEKK2, MEK5, and extracellular signal-related kinase 5 (

157 r mutation of the MEKK2 PB1 domain abolishes MEKK2-MEK5 complexes, demonstrating that the PB1 domain

158 which might correlate with a higher affinity MEKK2-MEK5 interaction.

159 t the PB1 domain interaction is required for MEKK2-MEK5 interactions.

160 that also binds ERK5, functionally forming a MEKK2-MEK5-ERK5 complex.

161 s regulated in part by the signaling complex MEKK2-MEK5-ERK5.

162 ain residues critical for the interaction of MEKK2/MEK5 and MEK5/ERK5 required for activation of the

163 discovery that root growth in a triple mekk1 mekk2 mekk3 mutant (mekk1/2/3), defective in a set of th

164 t, arsenite-mediated JNK activation requires MEKK2, MEKK3 and MEKK4.

165 Herein, we analyze the functional role of MEKK2, MEKK3, and MEK5 PB1 domains in the ERK5 activatio

166 is encoded within the N-terminal portion of MEKK2, MEKK3, and MEK5.

167 Mekk2(-/-) mice are viable and fertile.

168 y in FLS and that signal complexes including MEKK2, MKK4, MKK7, and/or JNK are potential therapeutic

169 by antigen cross-linking is dependent on the MEKK2-MKK7 pathway, and cytokine production in mast cell

170 , we showed that MEKK2 protein levels mirror MEKK2 mRNA levels.

171 e A23187, was inhibited by dominant negative MEKK2 mutants.

172 ells was also inhibited by dominant negative MEKK2 mutants.

173 Neither MEKK2 nor MLK3 have been previously shown to regulate tu

174 Targeted disruption of the MEKK2 or MEKK1 gene was used to abolish expression of th

175 The free PB1 domain of MEKK2 or MEKK3 functions effectively to inhibit the ERK5

176 Expression in cells of the MEKK2 or MEKK3 PB1 domain inhibits ERK5 activation, wher

177 beta abolish NF-kappaB activation induced by MEKK2 or MEKK3, thereby providing evidence that these IK

178 IkappaBalpha:NF-kappaB/IKK complex, whereas MEKK2 participates in assembling the IkappaBbeta:NF-kapp

179 Deletion or mutation of the MEKK2 PB1 domain abolishes MEKK2-MEK5 complexes, demonst

180 ter of basic amino acids in the front of the MEKK2 PB1 domain binding to the back-end acidic clusters

181 moiety, including the acidic cluster of the MEKK2 PB1 domain, is not required for MEK5 binding and b

182 Quiescent MEKK2 preferentially binds MEK5, and MEKK2 activation re

183 C-related kinase 2 (PRK2) was found to bind MEKK2; PRK2 has been previously shown to bind RhoA and t

184 We next analyzed a T-DNA insertion in the MEKK2 promoter region and found that although it does no

185 se brain by decreasing PTEN, RB1, and MAP3K2/MEKK2 protein expression, thereby increasing AKT activat

186 lly, using mass spectrometry, we showed that MEKK2 protein levels mirror MEKK2 mRNA levels.

187 JNK1 activation, whereas the related kinase MEKK2 regulates ERK5 activation.

188 results suggest a novel mechanism underlying MEKK2 regulation and activation.

189 Together, our data suggest a novel model for MEKK2 regulation and activation.

190 MEKK2 activation of PRK2 is independent of MEKK2 regulation of the c-Jun NH(2)-terminal kinase path

191 activated MPK4 is responsible for regulating MEKK2 RNA abundance.

192 promoter activity requires a functional Lad-MEKK2 signaling complex.

193 f multiple downstream targets, including the MEKK2 signaling pathway, inducing osteoblast differentia

194 Expression of JNK1, JNKK2, and MEKK2 significantly augmented the coprecipitation of, re

195 n was not blocked but moderately enhanced in Mekk2(-/-) T cells.

196 nase nor p38 MAPK activation was affected in Mekk2(-/-) T cells.

197 However, Mekk2(-/-) T-cell proliferation was augmented in respons

198 rn blot analysis demonstrated immunoreactive MEKK2, TAK1, and trace amounts of MEKK3 but not MEKK1 or

199 f MEKK2, it does prevent the upregulation of MEKK2 that is observed in mpk4 plants.

200 Consistently, Mekk2(-/-) thymocytes were more susceptible than wild-ty

201 MEKK2 translocation occurs more rapidly as the antigen c

202 d stimulation of T cells led to induction of MEKK2 tyrosine phosphorylation.

203 5 activation, whereas expression of a mutant MEKK2 unable to bind the MEK5 PB1 domain or expression o

204 In T cells, MEKK2 was found to be a strong activator of JNK but not

205 that strong and specific JNK1 activation by MEKK2 was mediated by the MAPKK JNK kinase 2 (JNKK2) rat

206 We found that MEKK2 was phosphorylated at Thr-283, which resulted in d

207 MEKK2 was required for epidermal growth factor receptor

208 Northern blot analysis showed that MEKK2 was ubiquitously expressed, with the highest level

209 kinase (JNK) subgroup of MAPK by the MAPKKK MEKK2, we found that strong and specific JNK1 activation

210 To elucidate the in vivo function of MEKK2, we generated mice carrying a targeted mutation in

211 Endogenous 14-3-3 protein and MEKK1 and MEKK2 were similarly distributed in the cell, consistent

212 MEK5 blocked the activation of BMK1/ERK5 by MEKK2, whereas activation of c-Jun N-terminal kinase (JN

213 Expression of T283A MEKK2 within a MEKK2(-/-) background enhanced stress-act