A0A3B2WC92 · A0A3B2WC92_MOUSE

Function

function

ATP-dependent microtubule severing protein that specifically recognizes and cuts microtubules that are polyglutamylated. Preferentially recognizes and acts on microtubules decorated with short polyglutamate tails: severing activity increases as the number of glutamates per tubulin rises from one to eight, but decreases beyond this glutamylation threshold. Severing activity is not dependent on tubulin acetylation or detyrosination. Microtubule severing promotes reorganization of cellular microtubule arrays and the release of microtubules from the centrosome following nucleation. It is critical for the biogenesis and maintenance of complex microtubule arrays in axons, spindles and cilia. SPAST is involved in abscission step of cytokinesis and nuclear envelope reassembly during anaphase in cooperation with the ESCRT-III complex. Recruited at the midbody, probably by IST1, and participates in membrane fission during abscission together with the ESCRT-III complex. Recruited to the nuclear membrane by IST1 and mediates microtubule severing, promoting nuclear envelope sealing and mitotic spindle disassembly during late anaphase. Required for membrane traffic from the endoplasmic reticulum (ER) to the Golgi and endosome recycling. Recruited by IST1 to endosomes and regulates early endosomal tubulation and recycling by mediating microtubule severing. Probably plays a role in axon growth and the formation of axonal branches.

Catalytic activity

  • n ATP + n H2O + a microtubule = n ADP + n phosphate + (n+1) alpha/beta tubulin heterodimers.
    EC:5.6.1.1 (UniProtKB | ENZYME | Rhea)

Activity regulation

Allosteric enzyme with a cooperative mechanism; at least two neighbor subunits influence each other strongly in spastin hexamers. Microtubule binding promotes cooperative interactions among spastin subunits.

Features

Showing features for binding site.

TypeIDPosition(s)Description
Binding site347-354ATP (UniProtKB | ChEBI)

GO annotations

AspectTerm
Cellular Componentcentrosome
Cellular Componentendoplasmic reticulum
Cellular Componentendosome
Cellular Componentmembrane
Cellular Componentmicrotubule
Cellular Componentmidbody
Cellular Componentnucleus
Cellular Componentperinuclear region of cytoplasm
Cellular Componentspindle
Molecular FunctionATP binding
Molecular FunctionATP hydrolysis activity
Molecular Functionisomerase activity
Molecular Functionmicrotubule binding
Molecular Functionmicrotubule severing ATPase activity
Biological Processaxonogenesis
Biological Processcytokinetic process
Biological Processendoplasmic reticulum to Golgi vesicle-mediated transport
Biological Processmicrotubule severing
Biological Processpositive regulation of microtubule depolymerization
Biological Processprotein hexamerization

Keywords

Enzyme and pathway databases

Names & Taxonomy

Protein names

  • Recommended name
    Spastin
  • EC number

Gene names

    • Name
      Spast
    • Synonyms
      SPAST
      , SPG4

Organism names

  • Taxonomic identifier
  • Organism
  • Strain
    • C57BL/6J
  • Taxonomic lineage
    Eukaryota > Metazoa > Chordata > Craniata > Vertebrata > Euteleostomi > Mammalia > Eutheria > Euarchontoglires > Glires > Rodentia > Myomorpha > Muroidea > Muridae > Murinae > Mus > Mus

Accessions

  • Primary accession
    A0A3B2WC92

Proteomes

Organism-specific databases

Subcellular Location

Membrane
; Peripheral membrane protein
Endoplasmic reticulum
Midbody
Cytoplasm, cytoskeleton
Cytoplasm, perinuclear region
Nucleus
Cytoplasm
Note: Forms an intramembrane hairpin-like structure in the membrane. Localization to the centrosome is independent of microtubules. Localizes to the midbody of dividing cells, and this requires CHMP1B. Enriched in the distal axons and branches of postmitotic neurons. Localizes to endoplasmic reticulum tubular network.

Features

Showing features for topological domain, intramembrane, transmembrane.

TypeIDPosition(s)Description
Topological domain1-54Cytoplasmic
Intramembrane55-75Helical
Transmembrane55-76Helical
Topological domain76-581Cytoplasmic

Keywords

Expression

Gene expression databases

Interaction

Subunit

Homohexamer. Mostly monomeric, but assembles into hexameric structure for short periods of time. Oligomerization seems to be a prerequisite for catalytic activity. Binding to ATP in a cleft between two adjacent subunits stabilizes the homohexameric form. Binds to microtubules at least in part via the alpha-tubulin and beta-tubulin tails. The hexamer adopts a ring conformation through which microtubules pass prior to being severed. Does not interact strongly with tubulin heterodimers. Interacts (via MIT domain) with CHMP1B; the interaction is direct. Interacts with SSNA1. Interacts with ATL1. Interacts with RTN1. Interacts with ZFYVE27. Interacts with REEP1. Interacts (via MIT domain) with IST1.

Family & Domains

Features

Showing features for region, motif, compositional bias, domain.

TypeIDPosition(s)Description
Region1-48Disordered
Motif4-11Nuclear localization signal
Compositional bias18-43Pro residues
Motif57-65Nuclear export signal
Region91-111Disordered
Domain114-191MIT
Region195-277Disordered
Compositional bias207-221Polar residues
Compositional bias256-270Polar residues
Motif274-277Nuclear localization signal
Domain339-475AAA+ ATPase

Sequence similarities

Belongs to the AAA ATPase family. Spastin subfamily.

Keywords

Phylogenomic databases

Family and domain databases

Sequence

  • Sequence status
    Complete
  • Length
    581
  • Mass (Da)
    62,737
  • Last updated
    2018-12-05 v1
  • Checksum
    2954EB5F5BB69CC1
MSSPAGRRKKKGSGGASPAPARPPPPAAVPAPAAGPAPAAGSPPKRNPSSFSSPLVVGFALLRLLACHLGLLFAWLCQRFSRALMAAKRSSGTAPAPASPSPPEPGPGGEAESVRVFHKQAFEYISIALRIDEEEKGQKEQAVEWYKKGIEELEKGIAVIVTGQGEQYERARRLQAKMMTNLVMAKDRLQLLESGAVPKRKDPLTHASNSLPRSKTVLKSGSAGLSGHHRAPSCSGLSMVSGARPGPGPAATTHKGTPKPNRTNKPSTPTTAVRKKKDLKNFRNVDSNLANLIMNEIVDNGTAVKFDDIAGQELAKQALQEIVILPSLRPELFTGLRAPARGLLLFGPPGNGKTMLAKAVAAESNATFFNISAASLTSKYVGEGEKLVRALFAVARELQPSIIFIDEVDSLLCERREGEHDASRRLKTEFLIEFDGVQSAGDDRVLVMGATNRPQELDEAVLRRFIKRVYVSLPNEETRLLLLKNLLCKQGSPLTQKELAQLARMTDGYSGSDLTALAKDAALGPIRELKPEQVKNMSASEMRNIRLSDFTESLKKIKRSVSPQTLEAYIRWNKDFGDTTV

Computationally mapped potential isoform sequences

There are 4 potential isoforms mapped to this entry

View all
EntryEntry nameGene nameLength
Q9QYY8SPAST_MOUSESpast614
A0A3B2WBA7A0A3B2WBA7_MOUSESpast191
A0A286YCJ4A0A286YCJ4_MOUSESpast300
A0A286YE25A0A286YE25_MOUSESpast613

Features

Showing features for compositional bias.

TypeIDPosition(s)Description
Compositional bias18-43Pro residues
Compositional bias207-221Polar residues
Compositional bias256-270Polar residues

Keywords

Sequence databases

Genome annotation databases

Similar Proteins

Disclaimer

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