N-alpha-acetyltransferase 25, NatB auxiliary subunit (NAA25)
The protein contains 972 amino acids for an estimated molecular weight of 112292 Da.
Non-catalytic subunit of the NatB complex which catalyzes acetylation of the N-terminal methionine residues of peptides beginning with Met-Asp-Glu. May play a role in normal cell-cycle progression. (updated: Feb. 4, 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.
- 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.
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| Variant | Description |
|---|---|
| dbSNP:rs16941860 | |
| a breast cancer sample; somatic mutation | |
| dbSNP:rs12231744 | |
| dbSNP:rs12298022 |
No binding partner found
Molecular Function
The reference OMIM entry for this protein is 612755
Mitochondrial distribution and morphology 20, yeast, homolog of
Mdm20
Chromosome 12 open reading frame 30; c12orf30
DESCRIPTION
MDM20 is a component of N-acetyltransferase complex B (NatB). Human NatB performs cotranslational N(alpha)-terminal acetylation of methionine residues when they are followed by asparagine (Starheim et al., 2008).CLONING
By searching a database for sequences similar to yeast Mdm20, Starheim et al. (2008) identified human MDM20. The deduced 972-amino acid protein has a calculated molecular mass of 112.3 kD. It has an N-terminal tetratricopeptide repeat and a putative C-terminal nuclear localization signal. MDM20 shares 20.4% and 92.9% amino acid identity with its yeast and mouse homologs, respectively. Western blot analysis detected MDM20 in all human cell lines examined. Immunofluorescence analysis of HeLa cells showed that MDM20 localized to the cytoplasm.GENE FUNCTION
Using reciprocal immunoprecipitation analysis and Western blot analysis, Starheim et al. (2008) showed that endogenous MDM20 and NAT3 (NAT5; 610833) interacted directly in HEK293 cells. The immunoprecipitated complex showed NatB activity against the synthetic peptide MDEL, but not against any other peptide examined. MDM20 and NAT3 also associated with isolated HEK293 polysomes, as well as in the cytosolic fraction. Knockdown of either protein via small interfering RNA disrupted cell cycle progression. Knockdown of NAT3 led to reduced cell proliferation and G0/G1 arrest, whereas knockdown of MDM20 decreased the number of cells in the G0/G1 phase and resulted in some cell death. Starheim et al. (2008) concluded that MDM20 is part of the NatB complex that acetylates the N-terminal sequence met-asp-, and they suggested that NatB may have an additional role in cell cycle progression.MAPPING
Hartz (2009) mapped the MDM20 gene to chromosome 12q24.13 based on an alignment of the MDM20 sequence (GenBank GENBANK AK023151) with the genomic sequence (build 36.1). ... More on the omim web site
Dec. 10, 2018: Protein entry updated
Automatic update: model status changed
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 16, 2016: Protein entry updated
Automatic update: OMIM entry 612755 was added.