ライフサイエンスコーパス: spastin

1 pression of the microtubule-severing protein Spastin.

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

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

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

5 does not regulate the enzymatic activity of spastin.

6 re worsened by depletion of endogenous mouse spastin.

7 sociated with expression of ATPase-defective spastin.

8 fferentially affect the severing activity of spastin.

9 s induced by the microtubule severing enzyme spastin.

10 ring on their own or in concert with VPS4 or spastin.

11 en mechanism that is independent of VPS4 and spastin.

12 astic paraplegia microtubule severing enzyme spastin.

13 on, we investigate here the cooperativity of spastin.

14 rotubule regulatory mechanisms distinct from Spastin.

15 lt from dominant-negative effects of mutated spastins.

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

17 cruit the microtubule-severing AAA(+) ATPase spastin, a close relative of VPS4, suggesting that spast

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

19 the hereditary spastic paraplegia protein M1 Spastin, a membrane-bound AAA ATPase found on LDs, coord

20 lylaminoquinazoline-based inhibitor bound to spastin, a microtubule-severing AAA protein, and charact

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

22 gene (SPAST), which is the gene that encodes spastin, a microtubule-severing protein.

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

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

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

26 We observed that spastin accumulates at shrinking ends; this increase in

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

28 We propose a model where spastin acts locally as an amplifier of MT polymerizatio

29 uorine modification can selectively target a spastin allele with an engineered cysteine mutation in i

30 severing resulting from inactivation of one spastin allele.

31 Spastin also displays an adjacent microtubule binding se

32 Spastin also influences the steady-state distribution of

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

34 The C448Y-mutated spastin alters microtubule stability in a manner that is

35 Spastin, an AAA ATPase mutated in the neurodegenerative

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

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

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

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

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

41 nction in the 'NoCut' abscission checkpoint (SPASTIN and CAPN7).

42 l of the disease that expresses human mutant spastin and displays adult-onset corticospinal degenerat

43 Spastin and Fidgetin are utilized to stimulate microtubu

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

45 Recent work with purified spastin and katanin accounts for this phenotype by showi

46 ein (MAP) signature, including the severases spastin and katanin and the microtubule regulators CRMP5

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

48 Recent work on spastin and katanin has partially resolved this paradox

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

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

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

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

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

54 cycling synaptic vesicles, are enriched with spastin, and are hotspots for new MT growth and synaptic

55 le-severing enzymes (MSEs), such as Katanin, Spastin, and Fidgetin play essential roles in cell divis

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

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

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

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

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

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

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

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

64 ich encodes the microtubule-severing protein spastin, are the most common cause of hereditary spastic

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

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

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

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

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

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

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

72 isoforms of endogenous spastin with healthy spastin at physiological levels, and prevented the onset

73 SPAST-C448Y mice, which express human mutant spastin at the ROSA26 locus, display corticospinal dieba

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

75 is not haploinsufficient but expresses human spastin bearing the HSP pathogenic C448Y mutation.

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

77 Here, we demonstrate that a human spastin binds weakly to unmodified peptides from the C-t

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

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

80 SPAST gene, which encodes a major isoform of spastin called M87 and a minor isoform called M1.

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

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

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

84 We found that spastin colocalized with CHMP1B-enriched sites but did n

85 umulates at shrinking ends; this increase in spastin concentration may underlie the increase in rescu

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

87 n, a close relative of VPS4, suggesting that spastin could have a VPS4-like role in normal-topology m

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

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

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

91 Mutant spastin demonstrated an abnormal interaction with microt

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

93 cells, we reveal that neurons deficient for spastin do not achieve the same level of presynaptic com

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

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

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

97 Overexpression of spastin dramatically enhances the formation of branches,

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

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

100 Drosophila melanogaster lacking spastin exhibit striking behavioral similarities to huma

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

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

103 Microtubule-severing enzymes - katanin, spastin, fidgetin - are related AAA-ATPases that cut mic

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

105 ggests how tubulin tail engagement activates spastin for microtubule disassembly.

106 First, M1 Spastin forms a tethering complex with peroxisomal ABCD1

107 ffers from a recently published structure of spastin from Drosophila melanogaster, which forms a six-

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

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

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

111 One possibility is that reduced spastin function, resulting in axonal swellings, is not

112 hting the importance of particular exons for spastin function.

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

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

115 the disease, results from mutations of human spastin gene (SPAST), which is the gene that encodes spa

116 On the other hand, mouse spastin gene (Spast)-knockout (KO) mice display axonal s

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

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

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

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

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

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

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

124 n-of-function mechanism underlying HSP, with spastin haploinsufficiency exacerbating the toxicity of

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

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

127 -EM structure of the Drosophila melanogaster spastin hexamer with a polyglutamate peptide bound in it

128 ve this paradox, we reconstituted Drosophila spastin in a dynamic microtubule assay and discovered th

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

130 GTPase domain that prevents interaction with spastin in cells.

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

132 ole for the microtubule (MT)-severing enzyme spastin in locally enhancing MT polymerization to influe

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

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

135 The role of Spastin in regulating neuronal microtubule stability sug

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

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

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

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

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

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

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

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

144 Spastin is a hexameric ring AAA ATPase that severs micro

145 Spastin is a member of the ATPases associated with diver

146 tion to its ATP-dependent severing activity, spastin is an ATP-independent regulator of microtubule d

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

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

149 Spastin is mutated in the axonopathy hereditary spastic

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

151 -to-peroxisome FA trafficking mediated by M1 Spastin is required to relieve LDs of lipid peroxidation

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

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

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

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

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

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

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

159 ic probes for studying cellular functions of spastin isoforms.

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

161 h their specific ESCRT-III binding partners (SPASTIN-IST1, KATNA1-CHMP3, and CAPN7-IST1), (2) functio

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

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

164 ulators includes the ATP-hydrolyzing enzymes spastin, katanin, and fidgetin, which sever microtubule

165 crotubule remodelers comprises the severases-spastin, katanin, and fidgetin-which cut microtubules in

166 and CAPN7-IST1), (2) function in abscission (SPASTIN, KATNA1, and CAPN7), and (3) function in the 'No

167 defects reminiscent of HSP (not observed in spastin knockout mice) were adult onset, as is typical o

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

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

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

171 The disruption of neuronal spastin level or activity, by CRISPRi-mediated depletion

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

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

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

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

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

177 resses the synaptic defects that result from spastin loss.

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

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

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

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

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

183 th the known importance of glutamylation for spastin microtubule severing activity.

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

185 We also report the crystal structure of the SPASTIN MIT domain in complex with the IST1 C-terminal t

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

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

188 tructure of the fluoro analogue bound to the spastin mutant.

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

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

191 ut exhibit a potent genetic interaction with spastin mutations.

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

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

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

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

196 This effect of severing and regrowth by spastin on the microtubule length distribution has not b

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

198 regeneration was unaffected by reduction of spastin or atlastin.

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

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

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

202 Conversely, Spastin overexpression destroys stable microtubules with

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

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

205 A cryo-EM structure of the spastin-peptide complex at 4.2 angstrom resolution revea

206 nd substrate binding organizes the conserved spastin pore loops into an ordered network that is allos

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

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

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

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

211 Mutant spastin proteins produce this toxic effect only when pre

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

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

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

215 ency exacerbating the toxicity of the mutant spastin proteins.

216 transfected with either wild type or mutant spastin proteins.

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

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

219 Second, M1 Spastin recruits the membrane-shaping ESCRT-III proteins

220 The AAA+ ATPase spastin remodels microtubule arrays through severing and

221 Spastin required the ability to sever MTs and to interac

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

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

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

225 M1 Spastin's dual roles in tethering LDs to peroxisomes and

226 A mathematical model shows that spastin's effect on microtubule dynamics is essential fo

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

228 ncrease in the microtubule mass accounts for spastin's in vivo phenotypes.

229 SSNA1 binding protects microtubules against spastin's severing activity.

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

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

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

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

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

235 nes encoding the microtubule-severing ATPase spastin (SPAST; SPG4), the membrane-bound GTPase atlasti

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

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

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

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

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

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

242 revealed an asymmetric hexamer in which five spastin subunits adopt a helical, spiral staircase confi

243 essential for this nucleation-like activity: spastin switches microtubules into a state where the net

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

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

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

247 Spastin, the most common locus for mutations in heredita

248 tion of the tubulin C-terminal tail recruits spastin to microtubules and modulates severing activity.

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

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

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

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

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

254 relative Vps4, and supports a model in which spastin utilizes a hand-over-hand mechanism of tubulin t

255 Expression of the mutant spastin was documented from fetus to adult, but gait def

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

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

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

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

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

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

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

263 These AAA unfoldases include spastin, which plays a critical role in the architecture

264 ssfully replaced both isoforms of endogenous spastin with healthy spastin at physiological levels, an

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

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

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

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

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