ライフサイエンスコーパス: spastin

1 le-severing proteins, namely P60-katanin and spastin.

2 hether or not the axons are also depleted of spastin.

3 em from being severed by P60-katanin than by spastin.

4 does not regulate the enzymatic activity of spastin.

5 sociated with expression of ATPase-defective spastin.

6 astic paraplegia microtubule severing enzyme spastin.

7 on, we investigate here the cooperativity of spastin.

8 rotubule regulatory mechanisms distinct from Spastin.

9 pression of the microtubule-severing protein Spastin.

10 lt from dominant-negative effects of mutated spastins.

11 potential gain-of-function effects of mutant spastins.

12 is caused by mutations in the gene encoding spastin, a member of the AAA family of ATPases.

13 The atlastin-1 GTPase interacts with spastin, a microtubule-severing ATPase, as well as with

14 s involved in endosomal trafficking and with spastin, a molecule implicated in microtubule interactio

15 he X-ray crystal structure of the Drosophila spastin AAA domain and provide a model for the active sp

16 ne encoding the microtubule-severing protein spastin account for most HSP cases.

17 ity of adult corticospinal tracts to loss of spastin activity.

18 severing resulting from inactivation of one spastin allele.

19 Spastin also displays an adjacent microtubule binding se

20 of the related microtubule-severing protein Spastin also reduces the class IV dendrite arbor, microt

21 Spastin, an AAA ATPase mutated in the neurodegenerative

22 These data suggest that spastin and atlastin function in the same biochemical pa

23 We propose that the HSP proteins spastin and atlastin promote axon regeneration by coordi

24 Mutations in >50 genes, including spastin and atlastin, lead to hereditary spastic paraple

25 Here, we show a physical interaction between spastin and atlastin, two autosomal dominant HSP gene pr

26 cortical neurons, where it colocalizes with spastin and atlastin-1.

27 Spastin and Fidgetin are utilized to stimulate microtubu

28 and reconcile existing Drosophila mutants of spastin and generate a new model for HSP by overexpressi

29 The mechanism by which spastin and katanin break and destabilize microtubules i

30 e sequence and functional similarity between spastin and katanin, we hypothesized that spastin promot

31 es co-expressing one copy of wild-type human spastin and one encoding the K388R catalytic domain muta

32 Spastin and P60-katanin are two distinct microtubule-sev

33 bers of the endosomal group of HSP proteins, spastin and spartin, are inhibitors of BMP signalling.

34 tion between the microtubule-severing enzyme spastin and the ESCRT protein IST1 at ER-endosome contac

35 a indicate that the HSP proteins atlastin-1, spastin, and REEP1 interact within the tubularER membran

36 RTN2 interacted with spastin, and this interaction required a hydrophobic reg

37 mutations in the SPG4 locus corresponding to spastin are the most common cause of hereditary spastic

38 ne encoding the microtubule-severing protein spastin are the most common cause of hereditary spastic

39 Mutations in spastin are the most common cause of the condition.

40 Mutations in spastin are the most frequent cause of the neurodegenera

41 Mutations in the SPG4 gene product spastin are the predominant genetic lesions associated w

42 dynamics observed in the presence of mutated spastins are not consistent with haploinsufficiency and

43 odes the microtubule-severing protein called spastin, are the most common cause of the disease.

44 icrotubules, supporting a role for wild-type spastin as a microtubule-severing protein.

45 Using full-length spastin as bait, we identified CHMP1B, a protein associa

46 hybrid screen on a brain cDNA library, using spastin as bait.

47 ps4 and the microtubule-severing function of spastin, as well as potentially katanin and fidgetin, ar

48 We show that Spastin assembles into a hexamer and that loops within t

49 ion, one based on the local concentration of spastin at branch sites and the other based on local det

50 the severing of microtubules through both a spastin-based mode and a katanin-based mode.

51 gly, none of these various findings apply to spastin, because the severing of microtubules by spastin

52 red for transport (ESCRT) component to which spastin binds, also had increased endosomal tubulation.

53 In mammalian cells, expression of mutant M1 spastins, but not their mutant M87 counterparts, promote

54 -acting modifiers of mutations affecting the Spastin catalytic domain.

55 ystem and the mechanism by which mutation in spastin causes axonal degeneration are unknown.

56 protein fragment complementation assays, and spastin co-immunoprecipitated with CHMP1B.

57 We also show that Spastin contains a second microtubule binding domain tha

58 We show that Drosophila Spastin (D-Spastin) is enriched in axons and synaptic co

59 A Drosophila homolog of spastin (D-spastin) was identified recently, and D-spast

60 tubule arrays such as those in neurons where spastin deficiency causes disease.

61 Mutant spastin demonstrated an abnormal interaction with microt

62 One hypothesis is that mutant spastin disrupts microtubule dynamics, causing an impair

63 tin, because the severing of microtubules by spastin does not appear to be strongly influenced by eit

64 We show that the spastin domain required for binding to atlastin lies wit

65 gated the effects of D-spastin, individual D-spastin domains, and D-spastin proteins bearing disease

66 Overexpression of spastin dramatically enhances the formation of branches,

67 Spastin encodes a microtubule (MT)-severing AAA ATPase (

68 Given that Spastin engages the MT in two places and that both inter

69 Drosophila melanogaster lacking spastin exhibit striking behavioral similarities to huma

70 small differences in the level of wild-type spastin expression can have significant functional conse

71 Quantitative data of spastin expression in specific regions of the nervous sy

72 hree different microtubule severing enzymes, Spastin, Fidgetin, and Katanin.

73 ring from AD-HSP, suggesting conservation of Spastin function between the species.

74 e intron 7-8 splice donor site to knock down spastin function in the developing zebrafish embryo.

75 In both Drosophila and humans, loss of Spastin function results in reduction of synaptic connec

76 hting the importance of particular exons for spastin function.

77 vitro evidence for additional, non-catalytic Spastin functions.

78 Mutations in the spastin gene (SPAST) are the most common cause of HSP an

79 We have screened the spastin gene for mutations in 15 families consistent wit

80 ation relates to the fact that the mammalian spastin gene has two start codons, resulting in a 616 am

81 n 15 families consistent with linkage to the spastin gene locus, SPG4, and have identified 11 mutatio

82 are most commonly caused by mutations in the spastin gene, which encodes a AAA+ ATPase related to the

83 m in HSP caused by missense mutations in the spastin gene.

84 spastic paraplegia (HSP) is mutation in the spastin gene.

85 w that cells lacking the MT-severing protein spastin had increased tubulation of and defective recept

86 The spastin hexamer forms a ring with a prominent central po

87 AA domain and provide a model for the active spastin hexamer generated using small-angle X-ray scatte

88 tive mutant subunits inhibit the activity of spastin in a hyperbolic dependence, characteristic for t

89 GTPase domain that prevents interaction with spastin in cells.

90 These data point to a role for spastin in intracellular membrane traffic events and pro

91 for a physiological and pathological role of spastin in membrane dynamics.

92 work in cell culture has proposed a role for Spastin in regulating microtubules.

93 The role of Spastin in regulating neuronal microtubule stability sug

94 st adult neurons but comprises 20-25% of the spastin in the adult spinal cord, the location of the ax

95 Both the normal function of spastin in the central nervous system and the mechanism

96 nce (RNAi), we have investigated the role of Spastin in vivo.

97 nt Spastin, we find that six mutant forms of Spastin, including three disease-associated forms, are s

98 e dynamics, whereas unbound M1 or M87 mutant spastins increased microtubule dynamics.

99 Here, we have investigated the effects of D-spastin, individual D-spastin domains, and D-spastin pro

100 CHMP1B and spastin interacted specifically in vitro and in vivo in

101 Using purified components, we also show that Spastin interacts directly with microtubules and is suff

102 Spastin is a hexameric ring AAA ATPase that severs micro

103 Spastin is a member of the ATPases associated with diver

104 In severing assays, wild type spastin is even more sensitive toward the presence of in

105 is more highly expressed in the neuron, but spastin is more concentrated at sites of branch formatio

106 Spastin is mutated in the axonopathy hereditary spastic

107 To gain insight into how spastin is regulated, we screened the Drosophila melanog

108 We show that Drosophila Spastin (D-Spastin) is enriched in axons and synaptic connections.

109 Its protein (spastin) is predicted to participate in the assembly or

110 Because the protein encoded by SPG4, termed spastin, is a microtubule-severing enzyme, a loss-of-fun

111 and M87) of the microtubule-severing protein spastin, is the chief gene mutated in hereditary spastic

112 The full-length human spastin isoform called M1 or a slightly shorter isoform

113 PAST, resulting in synthesis of a novel M187 spastin isoform that is able to sever microtubules.

114 n the predominantly cytoplasmic, full-length spastin isoform.

115 tion codons in SPAST allows synthesis of two spastin isoforms: a full-length isoform called M1 and a

116 ely well characterized family members, Vps4, spastin, katanin and fidgetin.

117 omplexes required for transport) pathway and spastin, katanin p60 and fidgetin affecting multiple asp

118 We previously demonstrated that reduction of spastin leads to a deficit in axon regeneration in a Dro

119 Interestingly, loss of spastin leads to a sparser microtubule array in axons an

120 ymerization of microtubules by expression of Spastin leads to their defective polarity and failure to

121 , P60-katanin levels plunge dramatically but spastin levels decline only slightly.

122 that P60-katanin levels are much higher than spastin levels during development.

123 We show that D-spastin, like katanin, displays ATPase activity and uses

124 obable cause for the neuronal dysfunction in spastin-linked HSP disease.

125 ibution, and synaptic transmission caused by spastin loss of function are all restored to wild type w

126 resses the synaptic defects that result from spastin loss.

127 The interaction was mediated by a region of spastin lying between residues 80 and 196 and containing

128 e situation, there are two major isoforms of spastin (M1 and M87) translated from two start codons.

129 ody inhibition experiments further show that spastin may dismantle microtubules by recognizing specif

130 Some mutated spastins may act in dominant-negative fashion to lower m

131 ns of these MT populations, we developed TRE-spastin mice to disrupt MTs in specific cell types.

132 PG4 that cannot be explained by insufficient spastin microtubule-severing activity.

133 In atlastin RNAi and spastin mutant animals, ER accumulation near single grow

134 e (ATP) binding, an ATP hydrolysis-deficient Spastin mutant predicted to remain kinetically trapped o

135 ellular and behavioral consequences of human spastin mutations and test hypotheses directly relevant

136 f-function" mechanism underlying HSP wherein spastin mutations produce a cytotoxic protein in the cas

137 ut exhibit a potent genetic interaction with spastin mutations.

138 e K388R catalytic domain mutation in the fly spastin null background, exhibit aberrant distal synapse

139 n rescues behavioral and cellular defects in spastin null flies equivalently.

140 istribution, similar to but less severe than spastin nulls.

141 isoform-specific toxic effects of mutant M1 spastin on FAT, and identify CK2 as a critical mediator

142 indicate that the toxic effects of mutant M1 spastins on FAT involve casein kinase 2 (CK2) activation

143 regeneration was unaffected by reduction of spastin or atlastin.

144 rexpressing the microtubule-severing protein Spastin or by inhibiting the C. elegans ninein homolog N

145 caused by mutations either in the SPG4 gene spastin or in the SPG3A gene atlastin.

146 Zebrafish spinal motor axons depleted of spastin or IST1 also had abnormal endosomal tubulation,

147 Conversely, Spastin overexpression destroys stable microtubules with

148 anogaster genome for deletions that modify a spastin overexpression phenotype, eye size reduction.

149 the largest cohorts of genetically confirmed spastin patients to date, contributes with the discovery

150 tent with disease-causing mutations in human spastin producing dominant-negative proteins and confirm

151 en spastin and katanin, we hypothesized that spastin promotes the dynamic disassembly and remodelling

152 Expression of this mutant spastin protein produces pathology in flies reminiscent

153 spastin, individual D-spastin domains, and D-spastin proteins bearing disease mutations on microtubul

154 Mutant spastin proteins produce this toxic effect only when pre

155 of FAT as a common toxic effect elicited by spastin proteins with different HSP mutations, independe

156 tubules, but also by neurotoxicity of mutant spastin proteins, chiefly M1.

157 s fortify a model wherein toxicity of mutant spastin proteins, especially mutant M1, contributes to a

158 transfected with either wild type or mutant spastin proteins.

159 lectively, our data support a model in which spastin pulls the C terminus of tubulin through its cent

160 HSP, which arises from dominant mutations in spastin rather than a complete loss of the gene.

161 Spastin required the ability to sever MTs and to interac

162 expression of wild-type Drosophila or human spastin rescues behavioral and cellular defects in spast

163 The excess spastin results in large numbers of short microtubules,

164 n (D-spastin) was identified recently, and D-spastin RNAi-treated or genetic null flies show neurolog

165 Elucidating spastin's function and disease mechanism will require a

166 The AAA ATPase Spastin severs microtubules along their lengths and is t

167 Using real-time imaging, we show that Spastin severs microtubules when added to permeabilized,

168 Epitope-tagged CHMP1B and spastin showed clear cytoplasmic co-localization in Cos-

169 rophe factors including kinesin-13/KLP-7 and spastin/SPAS-1.

170 ry protein 1 (REEP1), atlastin-1 (ATL1), and spastin (SPAST) - have been found to underlie many cases

171 in the AAA adenosine triphosphatase (ATPase) Spastin (SPG4) cause an autosomal dominant form of hered

172 P in humans; however, mutations in one gene, spastin (SPG4), are the cause of >40% of all cases.

173 caused by mutations in genes that encode the spastin (SPG4), atlastin-1 (SPG3A) and REEP1 (SPG31) pro

174 (ER) network formation: atlastin-1 (SPG3A), spastin (SPG4), reticulon 2 (SPG12), and receptor expres

175 ssion enhancing protein 1 (REEP1; SPG31), or spastin (SPG4).

176 Mutations in spastin, strumpellin, or REEP1 cause hereditary spastic

177 ides insights into the structural defects in spastin that arise from mutations identified in heredita

178 interaction required a hydrophobic region in spastin that is involved in ER localization and that is

179 t common cause of autosomal dominant HSP and Spastin (the SPG4 gene product) is a microtubule severin

180 Spastin, the most common locus for mutations in heredita

181 ur results reveal a critical requirement for spastin to promote axonal outgrowth during embryonic dev

182 into the ESCRT complex allows recruitment of spastin to promote fission of recycling tubules from the

183 new model for HSP by overexpression of a fly spastin transgene that carries a mutation prevalent in h

184 Two related enzymes, katanin and spastin, use the energy from ATP hydrolysis to sever mic

185 We set out to investigate the function of spastin using a yeast two-hybrid approach to identify in

186 quency of microtubule ends was observed when spastin was overexpressed in the neurons.

187 A Drosophila homolog of spastin (D-spastin) was identified recently, and D-spastin RNAi-tre

188 To identify binding partners for spastin, we carried out a yeast two-hybrid screen on a b

189 Using recombinant Spastin, we find that six mutant forms of Spastin, inclu

190 y and that it is the cytoplasmic function of spastin which is important for the pathogenesis of HSP.

191 FGF heightens expression of both katanin and spastin, which are proteins that sever microtubules in t

192 mediated by the microtubule-severing enzyme spastin, which is dysfunctional in some forms of upper m

193 The abnormal interaction of mutant spastin with microtubules was demonstrated to be associa

194 icate that an abnormal interaction of mutant spastin with microtubules, which disrupts organelle tran

195 ence of a transient interaction of wild-type spastin with microtubules, with resulting disassembly of

196 Depletion of either katanin or spastin with siRNA diminished but did not eliminate the

197 formed protein complexes with atlastin-1 and spastin within the tubular ER, and these interactions re