Autophagy-related protein 2 homolog A (ATG2A)
The protein contains 1938 amino acids for an estimated molecular weight of 212860 Da.
Involved in autophagosome assembly, regulating the size of nascent autophagosomes (PubMed:28561066). Also regulates lipid droplets morphology and distribution within the cell (PubMed:22219374, PubMed:28561066). Tethers the edge of the isolation membrane (IM) to the endoplasmic reticulum (ER) and mediates direct lipid transfer from ER to IM for IM expansion (By similarity). (updated: Oct. 7, 2020)
Protein identification was indicated in the following studies:
- 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.
- Chu and co-workers. (2018) Quantitative mass spectrometry of human reticulocytes reveal proteome-wide modifications during maturation. Br J Haematol. 180(1), 118-133.
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.
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| Variant | Description |
|---|---|
| dbSNP:rs12293826 | |
| dbSNP:rs35115827 | |
| dbSNP:rs60711419 | |
| dbSNP:rs2285347 | |
| dbSNP:rs656195 | |
| dbSNP:rs11827140 |
Biological Process
Autophagosome assembly
Autophagy of mitochondrion
Autophagy of nucleus
Late nucleophagy
Piecemeal microautophagy of the nucleus
Reticulophagy
The reference OMIM entry for this protein is 616225
Autophagy 2, s. cerevisiae, homolog of, a; atg2a
Kiaa0404
DESCRIPTION
Autophagy is an intracellular degradation process in which cytoplasmic materials are enclosed in autophagosomes at the endoplasmic reticulum and are delivered to the lysosome for degradation. ATG2A and ATG2B (616226) are autophagy-related proteins involved in the formation of autophagosomes and in the regulation of the size and distribution of lipid droplets (Velikkakath et al., 2012).CLONING
By searching for cDNAs encoding large proteins expressed in brain, Ishikawa et al. (1997) cloned ATG2A, which they called KIAA0404. The predicted protein contains 1,956 amino acids. RT-PCR analysis showed ubiquitous expression, with highest levels in placenta, lung, liver, and kidney. Velikkakath et al. (2012) reported that ATG2A and ATG2B share approximately 45% amino acid identity. They share approximately 16% identity with S. cerevisiae Atg2. Confocal microscopy demonstrated localization of ATG2A to autophagosome membranes and lipid droplets in HeLa cells.GENE FUNCTION
Using small interfering RNA (siRNA) experiments in HeLa cells, Velikkakath et al. (2012) showed that both ATG2A and ATG2B were required for autophagy. Cells lacking ATG2A and ATG2B accumulated unclosed autophagosome-related membranes. Deletion experiments revealed that localization of ATG2A to both lipid droplets and autophagosomes depended on the presence of amino acids 1723 to 1829, a sequence well conserved in ATG2B. Treatment with siRNA showed that lack of ATG2A and ATG2B led to aggregation of enlarged lipid droplets. Velikkakath et al. (2012) concluded that the ATG2 proteins function both in autophagosome formation and in the regulation of lipid droplet morphology and dispersion.MAPPING
By radiation hybrid analysis, Ishikawa et al. (1997) mapped the ATG2A gene to chromosome 11. Gross (2015) mapped the ATG2A gene to chromosome 11q13.1 based on an alignment of the ATG2A sequence (GenBank GENBANK AB007864) with the genomic sequence (GRCh38). ... More on the omim web site
Oct. 20, 2020: Protein entry updated
Automatic update: Entry updated from uniprot information.
Dec. 9, 2018: Protein entry updated
Automatic update: Entry updated from uniprot information.
Oct. 19, 2018: Additional information
Initial protein addition to the database. This entry was referenced in Bryk and co-workers. (2017).
Oct. 19, 2018: Protein entry updated
Automatic update: OMIM entry 616225 was added.