Q5R6G0 · ACTB_PONAB

Function

function

Actin is a highly conserved protein that polymerizes to produce filaments that form cross-linked networks in the cytoplasm of cells. Actin exists in both monomeric (G-actin) and polymeric (F-actin) forms, both forms playing key functions, such as cell motility and contraction. In addition to their role in the cytoplasmic cytoskeleton, G- and F-actin also localize in the nucleus, and regulate gene transcription and motility and repair of damaged DNA. Part of the ACTR1A/ACTB filament around which the dynactin complex is built. The dynactin multiprotein complex activates the molecular motor dynein for ultra-processive transport along microtubules (By similarity).

Miscellaneous

In vertebrates 3 main groups of actin isoforms, alpha, beta and gamma have been identified. The alpha actins are found in muscle tissues and are a major constituent of the contractile apparatus. The beta and gamma actins coexist in most cell types as components of the cytoskeleton and as mediators of internal cell motility.

Catalytic activity

GO annotations

AspectTerm
Cellular Componentactin cytoskeleton
Cellular Componentadherens junction
Cellular Componentapical junction complex
Cellular Componentbrush border
Cellular Componentcalyx of Held
Cellular Componentcortical cytoskeleton
Cellular Componentcytoplasmic ribonucleoprotein granule
Cellular Componentcytoskeleton
Cellular Componentcytosol
Cellular Componentdense body
Cellular Componentfocal adhesion
Cellular Componentglutamatergic synapse
Cellular Componentlamellipodium
Cellular ComponentNuA4 histone acetyltransferase complex
Cellular Componentnucleosome
Cellular Componentnucleus
Cellular Componentplasma membrane
Cellular Componentpostsynaptic actin cytoskeleton
Cellular Componentprotein-containing complex
Cellular Componentribonucleoprotein complex
Cellular ComponentSchaffer collateral - CA1 synapse
Cellular Componenttight junction
Molecular FunctionATP binding
Molecular FunctionATP hydrolysis activity
Molecular Functionidentical protein binding
Molecular Functionkinesin binding
Molecular Functionnitric-oxide synthase binding
Molecular Functionprotein kinase binding
Molecular Functionstructural constituent of postsynaptic actin cytoskeleton
Molecular FunctionTat protein binding
Biological Processadherens junction assembly
Biological Processapical protein localization
Biological Processcell motility
Biological Processcellular response to cytochalasin B
Biological Processestablishment or maintenance of cell polarity
Biological Processmorphogenesis of a polarized epithelium
Biological Processpositive regulation of double-strand break repair via homologous recombination
Biological Processprotein localization to adherens junction
Biological Processregulation of cell cycle
Biological Processregulation of norepinephrine uptake
Biological Processregulation of protein localization to plasma membrane
Biological Processregulation of synaptic vesicle endocytosis
Biological Processregulation of transepithelial transport

Keywords

Enzyme and pathway databases

Names & Taxonomy

Protein names

Gene names

    • Name
      ACTB

Organism names

Accessions

  • Primary accession
    Q5R6G0
  • Secondary accessions
    • Q5R582

Proteomes

PTM/Processing

Features

Showing features for initiator methionine, modified residue, chain.

TypeIDPosition(s)Description
Initiator methionine1Removed; alternate
Modified residue1N-acetylmethionine
ChainPRO_00002918711-375Actin, cytoplasmic 1
Modified residue2N-acetylaspartate; in Actin, cytoplasmic 1, N-terminally processed
ChainPRO_00003670792-375Actin, cytoplasmic 1, N-terminally processed
Modified residue44Methionine (R)-sulfoxide
Modified residue47Methionine (R)-sulfoxide
Modified residue73Tele-methylhistidine
Modified residue84N6-methyllysine

Post-translational modification

Actin, cytoplasmic 1

N-terminal cleavage of acetylated methionine of immature cytoplasmic actin by ACTMAP.
ISGylated.
Oxidation of Met-44 and Met-47 by MICALs (MICAL1, MICAL2 or MICAL3) to form methionine sulfoxide promotes actin filament depolymerization. MICAL1 and MICAL2 produce the (R)-S-oxide form. The (R)-S-oxide form is reverted by MSRB1 and MSRB2, which promote actin repolymerization.
Monomethylation at Lys-84 (K84me1) regulates actin-myosin interaction and actomyosin-dependent processes. Demethylation by ALKBH4 is required for maintaining actomyosin dynamics supporting normal cleavage furrow ingression during cytokinesis and cell migration.

Actin, cytoplasmic 1, N-terminally processed

N-terminal acetylation by NAA80 affects actin filament depolymerization and elongation, including elongation driven by formins. In contrast, filament nucleation by the Arp2/3 complex is not affected.
Methylated at His-73 by SETD3 (By similarity).
Methylation at His-73 is required for smooth muscle contraction of the laboring uterus during delivery (By similarity).

Keywords

Interaction

Subunit

Polymerization of globular actin (G-actin) leads to a structural filament (F-actin) in the form of a two-stranded helix. Each actin can bind to 4 others. Identified in a IGF2BP1-dependent mRNP granule complex containing untranslated mRNAs. Component of the BAF complex, which includes at least actin (ACTB), ARID1A, ARID1B/BAF250, SMARCA2, SMARCA4/BRG1, ACTL6A/BAF53, ACTL6B/BAF53B, SMARCE1/BAF57 SMARCC1/BAF155, SMARCC2/BAF170, SMARCB1/SNF5/INI1, and one or more of SMARCD1/BAF60A, SMARCD2/BAF60B, or SMARCD3/BAF60C. In muscle cells, the BAF complex also contains DPF3. Found in a complex with XPO6, Ran, ACTB and PFN1. Interacts with PFN1. Interacts with XPO6 and EMD. Interacts with ERBB2. Interacts with GCSAM (By similarity).
Interacts with TBC1D21 (By similarity).
Interacts with CPNE1 (via VWFA domain) and CPNE4 (via VWFA domain) (By similarity).
Interacts with DHX9 (via C-terminus); this interaction is direct and mediates the attachment to nuclear ribonucleoprotein complexes. Interacts with FAM107A (By similarity).
Part of the ACTR1A/ACTB filament around which the dynactin complex is built. The filament contains 8 copies of ACTR1A and 1 ACTB (By similarity).
Interacts with TPRN which forms ring-like structures in the stereocilium taper region; the interaction may stabilize stereocilia in inner ear hair cells (By similarity).
Interacts with AMOTL2 (via N-terminus), the interaction facilitates binding of cell junction complexes to actin fibers in endothelial cells (By similarity).

Protein-protein interaction databases

Structure

Family & Domains

Sequence similarities

Belongs to the actin family.

Phylogenomic databases

Family and domain databases

Sequence

  • Sequence status
    Complete
  • Length
    375
  • Mass (Da)
    41,737
  • Last updated
    2004-12-21 v1
  • Checksum
    6AFD05CA94E360E2
MDDDIAALVVDNGSGMCKAGFAGDDAPRAVFPSIVGRPRHQGVMVGMGQKDSYVGDEAQSKRGILTLKYPIEHGIVTNWDDMEKIWHHTFYNELRVAPEEHPVLLTEAPLNPKANREKMTQIMFETFNTPAMYVAIQAVLSLYASGRTTGIVMDSGDGVTHTVPIYEGYALPHAILRLDLAGRDLTDYLMKILTERGYSFTTTAEREIVRDIKEKLCYVALDFEQEMATAASSSSLEKSYELPDGQVITIGNERFRCPEALFQPSFLGMESCGIHETTFNSIMKCDVDIRKDLYANTVLSGGTTMYPGIADRMQKEITALAPSTMKIKIIAPPERKYSVWIGGSILASLSTFQQMWISKQEYDESGPSIVHRKCF

Features

Showing features for sequence conflict.

TypeIDPosition(s)Description
Sequence conflict288in Ref. 1; CAH93084

Keywords

Sequence databases

Nucleotide SequenceProtein SequenceMolecule TypeStatus
CR860530
EMBL· GenBank· DDBJ
CAH92656.1
EMBL· GenBank· DDBJ
mRNA
CR860982
EMBL· GenBank· DDBJ
CAH93084.1
EMBL· GenBank· DDBJ
mRNA

Genome annotation databases

Similar Proteins

Disclaimer

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