Actin, cytoplasmic 2 (ACTG1)
The protein contains 375 amino acids for an estimated molecular weight of 41793 Da.
Actins are highly conserved proteins that are involved in various types of cell motility and are ubiquitously expressed in all eukaryotic cells. (updated: April 1, 2015)
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.
- Lange and co-workers. (2014) Annotating N termini for the human proteome project: N termini and Nα-acetylation status differentiate stable cleaved protein species from degradation remnants in the human erythrocyte proteome. J Proteome Res. 13(4), 2028-2044.
- 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.
- Bryk and co-workers. (2017) Quantitative Analysis of Human Red Blood Cell Proteome. J Proteome Res. 16(8), 2752-2761.
- D'Alessandro and co-workers. (2017) Red blood cell proteomics update: is there more to discover? Blood Transfus. 15(2), 182-187.
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.
This protein is annotated as membranous in Gene Ontology.
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Biological Process
Adherens junction organization
Angiogenesis
Axon guidance
Cell junction assembly
Cell-cell junction organization
Cellular response to interferon-gamma
Ephrin receptor signaling pathway
Fc-gamma receptor signaling pathway involved in phagocytosis
Innate immune response
Maintenance of blood-brain barrier
Membrane organization
Morphogenesis of a polarized epithelium
Movement of cell or subcellular component
Platelet aggregation
Positive regulation of cell migration
Positive regulation of gene expression
Positive regulation of wound healing
Protein localization to bicellular tight junction
Regulation of focal adhesion assembly
Regulation of stress fiber assembly
Regulation of transepithelial transport
Response to calcium ion
Response to mechanical stimulus
Retina homeostasis
Sarcomere organization
Synaptic vesicle endocytosis
Tight junction assembly
Vascular endothelial growth factor receptor signaling pathway
Cellular Component
Actin filament
Apical junction complex
Basal body patch
Blood microparticle
Calyx of Held
Cell-cell junction
Cytoskeleton
Cytosol
Dense body
Extracellular exosome
Extracellular matrix
Extracellular space
Filamentous actin
Focal adhesion
Membrane
Myelin sheath
Myofibril
Nucleus
Phagocytic vesicle
Plasma membrane
Postsynaptic actin cytoskeleton
Presynaptic actin cytoskeleton
Schaffer collateral - CA1 synapse
The reference OMIM entry for this protein is 102560
Actin, gamma-1; actg1
Actin, gamma; actg
Cytoskeletal gamma-actin
Actin, cytoplasmic, 2
DESCRIPTION
Actins are a family of highly conserved cytoskeletal proteins that play fundamental roles in nearly all aspects of eukaryotic cell biology. The ability of a cell to divide, move, endocytose, generate contractile force, and maintain shape is reliant upon functional actin-based structures. Actin isoforms are grouped according to expression patterns: muscle actins predominate in striated and smooth muscle (e.g., ACTA1, 102610, and ACTA2, 102620, respectively), whereas the 2 cytoplasmic nonmuscle actins, gamma-actin (ACTG1) and beta-actin (ACTB; 102630), are found in all cells (Sonnemann et al., 2006).CLONING
Using chick beta-actin cDNA as probe, Gunning et al. (1983) cloned beta-actin and gamma-actin from a fibroblast cDNA library. They noted that the N-terminal methionine is posttranslationally removed from the mature beta-actin and gamma-actin proteins. Erba et al. (1986) presented the complete sequence of gamma-actin mRNA. They noted that gamma- and beta-actin differ by only 4 amino acids at their conserved N-terminal ends. By screening a promyelocytic leukemia cell line cDNA library with chicken beta-actin, Chou et al. (1987) cloned human gamma-actin. The deduced protein contains 375 amino acids. Northern blot analysis of human fetal tissues detected highest expression of a 2.35-kb transcript in brain and kidney, with weaker expression in liver and trophoblasts. High expression was also detected in a human hepatoma cell line. Expression of gamma-actin increased during macrophage differentiation in a neuroblastoma cell line. By Northern blot analysis of mouse tissues, Erba et al. (1988) detected high gamma-actin expression in lung, kidney, and testis, moderate expression in brain, low expression in stomach, and very low expression in liver, heart, and muscle.GENE FUNCTION
Leisel et al. (1999) used pure components of the actin cytoskeleton to reconstitute sustained movement in Listeria and Shigella in vitro. Actin-based propulsion was driven by the free energy released by ATP hydrolysis linked to actin polymerization and did not require myosin (see 601478). In addition to actin and activated Arp2/3 complex (see 604221), actin depolymerizing factor and capping protein (see 601571) were also required for motility as they maintained a high steady-state level of G-actin, (monomeric, or globular, actin) which controls the rate of unidirectional growth of actin filaments at the surface of the bacterium. The movement was more effective when profilin (see 176590), alpha-actinin (see 102575), and, in the case of Listeria, VASP (601703) were also included. Tzima et al. (2000) showed that annexin V (ANXA5; 131230) bound filamentous actin (F-actin) and gamma-actin, but not beta-actin, in activated human platelets. Interaction of phospholipase D (see PLD1; 602382) with actin microfilaments regulates cell proliferation, vesicle trafficking, and secretion. Kusner et al. (2002) found that highly purified G-actin inhibited both basal and stimulated PLD1 activity, whereas F-actin had the opposite effect. Actin-induced modulation of PLD1 activity was independent of the activating stimulus. The effects of actin on PLD1 were isoform specific: human platelet actin, which exists in a 5:1 ratio of beta- and gamma-actin, was only 45% as potent and 40% as efficacious as rabbit skeletal muscle alpha-actin. The mammalian cytoskeletal proteins beta- and gamma-actin are highly homologous, but only beta-actin is N-termina ... More on the omim web site
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
June 20, 2017: Protein entry updated
Automatic update: comparative model was added.
March 15, 2016: Protein entry updated
Automatic update: OMIM entry 102560 was added.