Actin-related protein 2/3 complex subunit 4 (ARPC4)
The protein contains 168 amino acids for an estimated molecular weight of 19667 Da.
Actin-binding component of the Arp2/3 complex, a multiprotein complex that mediates actin polymerization upon stimulation by nucleation-promoting factor (NPF) (PubMed:9230079). The Arp2/3 complex mediates the formation of branched actin networks in the cytoplasm, providing the force for cell motility (PubMed:9230079). In addition to its role in the cytoplasmic cytoskeleton, the Arp2/3 complex also promotes actin polymerization in the nucleus, thereby regulating gene transcription and repair of damaged DNA (PubMed:29925947). The Arp2/3 complex promotes homologous recombination (HR) repair in response to DNA damage by promoting nuclear actin polymerization, leading to drive motility of double-strand breaks (DSBs) (PubMed:29925947). (updated: Nov. 7, 2018)
Protein identification was indicated in the following studies:
- Goodman and co-workers. (2013) The proteomics and interactomics of human erythrocytes. Exp Biol Med (Maywood) 238(5), 509-518.
- Hegedűs and co-workers. (2015) Inconsistencies in the red blood cell membrane proteome analysis: generation of a database for research and diagnostic applications. Database (Oxford) 1-8.
- Wilson and co-workers. (2016) Comparison of the Proteome of Adult and Cord Erythroid Cells, and Changes in the Proteome Following Reticulocyte Maturation. Mol Cell Proteomics. 15(6), 1938-1946.
- D'Alessandro and co-workers. (2017) Red blood cell proteomics update: is there more to discover? Blood Transfus. 15(2), 182-187.
- Bryk and co-workers. (2017) Quantitative Analysis of Human Red Blood Cell Proteome. J Proteome Res. 16(8), 2752-2761.
Methods
The following articles were analysed to gather the proteome content of erythrocytes.
The gene or protein list provided in the studies were processed using the ID mapping API of Uniprot in September 2018. The number of proteins identified and mapped without ambiguity in these studies is indicated below.
Only Swiss-Prot entries (reviewed) were considered for protein evidence assignation.
| Publication | Identification 1 | Uniprot mapping 2 | Not mapped / Obsolete | TrEMBL | Swiss-Prot |
|---|---|---|---|---|---|
| Goodman (2013) | 2289 (gene list) | 2278 | 53 | 20599 | 2269 |
| Lange (2014) | 1234 | 1234 | 7 | 28 | 1224 |
| Hegedus (2015) | 2638 | 2622 | 0 | 235 | 2387 |
| Wilson (2016) | 1658 | 1528 | 170 | 291 | 1068 |
| d'Alessandro (2017) | 1826 | 1817 | 2 | 0 | 1815 |
| Bryk (2017) | 2090 | 2060 | 10 | 108 | 1942 |
| Chu (2018) | 1853 | 1804 | 55 | 362 | 1387 |
1 as available in the article and/or in supplementary material
2 uniprot mapping returns all protein isoforms as one entry
The compilation of older studies can be retrieved from the Red Blood Cell Collection database.
The data and differentiation stages presented below come from the proteomic study and analysis performed by our partners of the GReX consortium, more details are available in their published work.
(right-click above to access to more options from the contextual menu)
Biological Process
Actin filament polymerization
Actin nucleation
Arp2/3 complex-mediated actin nucleation
Axon guidance
Ephrin receptor signaling pathway
Fc-gamma receptor signaling pathway involved in phagocytosis
Innate immune response
Membrane organization
The reference OMIM entry for this protein is 604226
Actin-related protein 2/3 complex, subunit 4; arpc4
Actin-related protein 2/3 complex, 20-kd subunit; arc20
P20-arc
The Arp2/3 protein complex has been implicated in the control of actin polymerization in cells. The human complex consists of 7 subunits: the actin-related proteins ARP2 (ACTR2; 604221) and ARP3 (ACTR3; 604222), ARC41 (ARPC1B; 604223), ARC34 (ARPC2; 604224), ARC21 (ARPC3; 604225), ARC20 (ARPC4), and ARC16 (ARPC5; 604227). See ACTR2 for additional information about the Arp2/3 complex.
CLONING
By searching an EST database with peptide sequences from the 7 subunits of the human ARP2/3 complex, Welch et al. (1997) identified full-length human cDNAs encoding each subunit. The ARC20 cDNA encodes a deduced 168-amino acid protein that is 68% and 67% identical to its homologs in S. pombe and S. cerevisiae, respectively. Machesky et al. (1997) purified the ARP2/3 complex from human neutrophils and sequenced peptides from each of the subunits.GENE FUNCTION
Volkmann et al. (2001) performed electron cryomicroscopy and 3-dimensional reconstruction of Acanthamoeba castellanii and S. cerevisiae Arp2/3 complexes bound to the WASP (301000) carboxy-terminal domain. Asymmetric, oblate ellipsoids were revealed. Image analysis of actin branches indicated that the complex binds the side of the mother filament, and ARP2 and ARP3 are the first 2 subunits of the daughter filament. Comparison to the actin-free WASP-activated complexes suggests that branch initiation involves large-scale structural rearrangements within ARP2/3.BIOCHEMICAL FEATURES
- Crystal Structure Robinson et al. (2001) determined the crystal structure of bovine ARP2/3 complex at 2.0-angstrom resolution. ARP2 and ARP3 are folded like actin, with distinctive surface features. Subunits ARPC2 and ARPC4 in the core of the complex associate through long carboxy-terminal alpha helices and have similarly folded amino-terminal alpha/beta domains. ARPC1 is a 7-blade beta propeller with an insertion that may associate with the side of an actin filament. ARPC3 and ARPC5 are globular alpha-helical subunits. Robinson et al. (2001) predicted that WASP/SCAR proteins activate ARP2/3 complex by bringing ARP2 into proximity with ARP3 for nucleation of a branch on the side of a preexisting actin filament. ... More on the omim web site
Nov. 16, 2018: Protein entry updated
Automatic update: Entry updated from uniprot information.
Feb. 2, 2018: Protein entry updated
Automatic update: Uniprot description updated
Dec. 19, 2017: Protein entry updated
Automatic update: Uniprot description updated
Nov. 23, 2017: Protein entry updated
Automatic update: Uniprot description updated
March 25, 2017: Additional information
No protein expression data in P. Mayeux work for ARPC4
March 15, 2016: Protein entry updated
Automatic update: OMIM entry 604226 was added.