V-type proton ATPase subunit B, brain isoform (ATP6V1B2)

The protein contains 511 amino acids for an estimated molecular weight of 56501 Da.

 

Non-catalytic subunit of the V1 complex of vacuolar(H+)-ATPase (V-ATPase), a multisubunit enzyme composed of a peripheral complex (V1) that hydrolyzes ATP and a membrane integral complex (V0) that translocates protons (By similarity). V-ATPase is responsible for acidifying and maintaining the pH of intracellular compartments and in some cell types, is targeted to the plasma membrane, where it is responsible for acidifying the extracellular environment (PubMed:32001091). In renal intercalated cells, can partially compensate the lack of ATP6V1B1 and mediate secretion of protons (H+) into the urine under base-line conditions but not in conditions of acid load (By similarity). (updated: June 2, 2021)

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. 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.
  3. 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.
  4. 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.
  5. Bryk and co-workers. (2017) Quantitative Analysis of Human Red Blood Cell Proteome. J Proteome Res. 16(8), 2752-2761.
  6. D'Alessandro and co-workers. (2017) Red blood cell proteomics update: is there more to discover? Blood Transfus. 15(2), 182-187.
  7. 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.

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 Gene Ontology, is annotated as membranous in UniProt.


Interpro domains
Total structural coverage: 93%
Model score: 0
No model available.

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VariantDescription
ZLS2

The reference OMIM entry for this protein is 606939

Atpase, h+ transporting, lysosomal, 56/58-kd, v1 subunit b, isoform 2; atp6v1b2
Atp6b2
Vacuolar proton pump b isoform 2

DESCRIPTION

ATP6B2 encodes a component of vacuolar ATPase (V-ATPase), a multisubunit enzyme that mediates acidification of intracellular organelles. The encoded protein is one of 2 B subunit isoforms contained within the catalytic domain. See also ATP6B1 (192132).

CLONING

By using the consensus PCR primers to the V-ATPase B subunit, Bernasconi et al. (1990) cloned a partial ATP6B2 cDNA from a human brain cDNA library. The deduced 511-amino acid protein shares 90% sequence identity with ATP6B1 and is expressed in human brain as a 3.2-kb transcript. Nelson et al. (1992) cloned the full-length ATP6B2 cDNA from a human kidney cDNA library. Sequence analysis of the B1 and B2 isoforms indicated a high degree of conservation in the internal region of the protein, but divergence at the N- and C-termini. Van Hille et al. (1994) cloned isoform B2, which they called HO57, by RT-PCR with osteoclastoma mRNA. They found ubiquitous expression of 3 mRNA species of 1.6, 2.6, and 2.8 kb. High levels of expression were found in brain and kidney and in the originating osteoclastoma, intermediate levels in pancreas, and lower levels in liver, lung, placenta, heart, and muscle. By in situ hybridization of osteoclastoma tumors, they found a high level of B2 transcript in osteoclast cells. In day 16 postcoitum mouse embryos, high levels of subunit B mRNA were observed in the fifth cranial ganglia of brain and in the developing tubule network of the kidney. High levels of transcript were also detected in vertebrae, rib, and lower jaw bone within large cells showing morphologic features characteristic of osteoclasts.

GENE FUNCTION

Using antibodies to isoform B2, Lee et al. (1995) immunoprecipitated several subunits of the V-ATPase complex and confirmed the presence of isoform B2. They also found that the amount of V-ATPase recovered increased with monocyte differentiation. By nuclear runoff analysis, they determined that ATP6B2 mRNA is specifically transcriptionally upregulated during differentiation of both native monocytes and cells of a human monocytic leukemia cell line.

GENE STRUCTURE

Lee et al. (1995) found that the 5-prime flanking region contains a TATA-less promoter with a high G+C content and multiple AP2 and SP1 binding sites in the 5-prime UTR and proximal coding region.

MAPPING

The International Radiation Hybrid Mapping Consortium mapped the ATP6B2 gene to chromosome 8 (TMAP stSG1675). ... More on the omim web site

Subscribe to this protein entry history

July 1, 2021: 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

March 16, 2016: Protein entry updated
Automatic update: OMIM entry 606939 was added.