E3 ubiquitin-protein transferase MAEA (MAEA)

The protein contains 396 amino acids for an estimated molecular weight of 45287 Da.

 

Core component of the CTLH E3 ubiquitin-protein ligase complex that selectively accepts ubiquitin from UBE2H and mediates ubiquitination and subsequent proteasomal degradation of the transcription factor HBP1. MAEA and RMND5A are both required for catalytic activity of the CTLH E3 ubiquitin-protein ligase complex (PubMed:29911972). MAEA is required for normal cell proliferation (PubMed:29911972). The CTLH E3 ubiquitin-protein ligase complex is not required for the degradation of enzymes involved in gluconeogenesis, such as FBP1 (PubMed:29911972). Plays a role in erythroblast enucleation during erythrocyte maturation and in the development of mature macrophages (By similarity). Mediates the attachment of erythroid cell to mature macrophages; this MAEA-mediated contact inhibits erythroid cell apoptosis (PubMed:9763581). Participates in erythroblastic island formation, which is the functional unit of definitive erythropoiesis. Associates with F-actin to regulate actin distribution in erythroblasts and macrophages (By similarity). May contribute to nuclear architecture and cells division events (Probable). (updated: Sept. 12, 2018)

Protein identification was indicated in the following studies:

  1. Goodman and co-workers. (2013) The proteomics and interactomics of human erythrocytes. Exp Biol Med (Maywood) 238(5), 509-518.
  2. 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.
  3. 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.

PublicationIdentification 1Uniprot mapping 2Not mapped /
Obsolete
TrEMBLSwiss-Prot
Goodman (2013)2289 (gene list)227853205992269
Lange (2014)123412347281224
Hegedus (2015)2638262202352387
Wilson (2016)165815281702911068
d'Alessandro (2017)18261817201815
Bryk (2017)20902060101081942
Chu (2018)18531804553621387

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.

No sequence conservation computed yet.

This protein is annotated as membranous in UniProt.


Interpro domains
Total structural coverage: 34%
Model score: 0
No model available.

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VariantDescription
dbSNP:rs34082974

The reference OMIM entry for this protein is 606801

Macrophage erythroblast attacher; maea
Erythroblast macrophage protein; emp

DESCRIPTION

The association of erythroblasts with macrophages plays a central role in the terminal maturation and enucleation of erythroblasts. MAEA mediates attachment of erythroblasts to macrophages.

CLONING

Hanspal et al. (1998) cloned an MAEA cDNA from a human macrophage cDNA expression library using antibody to the purified protein as probe. The deduced 395-amino acid protein has a small N-terminal domain, a single transmembrane domain, and a large cytoplasmic domain containing several tyrosine residues that, when phosphorylated, could interact with protein recognition modules. MAEA has a calculated molecular mass of 43 kD. Recombinant protein, and protein expressed by transfected COS-7 cells, showed an apparent molecular mass of 36 kD by SDS-PAGE. By Northern blot analysis, Hanspal et al. (1998) found ubiquitous expression of a 2.1-kb transcript in all tissues and cells examined. By Western blot analysis, they identified 2 isoforms with apparent molecular masses of 36 kD and 33 kD in macrophage membranes.

GENE FUNCTION

Using several cell attachment assays, Hanspal et al. (1998) found that both MAEA isoforms could bind erythroblasts and that binding was mediated by the extracellular N terminus. They also determined that MAEA-mediated cell-cell contact prevents apoptosis in maturing erythroblasts.

MAPPING

The International Radiation Hybrid Mapping Consortium mapped the MAEA gene to chromosome 4 (TMAP WI-13069). ... More on the omim web site

Subscribe to this protein entry history

Oct. 2, 2018: Protein entry updated
Automatic update: Entry updated from uniprot information.

Feb. 10, 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 16, 2016: Protein entry updated
Automatic update: OMIM entry 606801 was added.