PRA1 family protein 2 (PRAF2)
The protein contains 178 amino acids for an estimated molecular weight of 19258 Da.
May be involved in ER/Golgi transport and vesicular traffic. Plays a proapoptotic role in cerulenin-induced neuroblastoma apoptosis. (updated: Jan. 31, 2018)
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.
- 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.
This protein is predicted to be membranous by TOPCONS.
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| Variant | Description |
|---|---|
| dbSNP:rs34565429 |
No binding partner found
Molecular Function
The reference OMIM entry for this protein is 300840
Pra1 domain family, member 2; praf2
Jm4
DESCRIPTION
PRAF2 belongs to the prenylated RAB acceptor-1 (PRA1, or RABAC1; 604925) domain family (PRAF). Members of this family have 4 transmembrane domains, hydrophilic N and C termini, and a PRA1 domain. PRAF proteins are involved in multiple cellular processes, including endo- and exocytic vesicle trafficking and glutamate uptake (summary by Borsics et al., 2010).CLONING
Using a yeast 2-hybrid screen of a B-cell cDNA library with the C terminus of CCR5 (601373) as bait, followed by database analysis, Schweneker et al. (2005) identified PRAF2, which they called JM4 (Jena-Muenchen-4). The predicted 178-amino acid protein contains 4 transmembrane-spanning domains and is evolutionarily conserved. It shares 42% amino acid identity, as well as structural similarity, with JWA (ARL6IP5; 605709). Northern blot analysis revealed near ubiquitous expression of a 1.2-kb transcript in human tissues. Cell fractionation and Western blot analysis showed association of JM4 with cellular membranes in transfected canine thymocytes. Confocal microscopy demonstrated colocalization of JM4 with JWA, as well as with calnexin (CANX; 114217), an endoplasmic reticulum marker, and M6PR (154540), a trans-Golgi network and endosome marker, in granular structures of transfected HeLa and COS cells. Fo et al. (2006) determined that the human PRAF2 protein contains an N-terminal amphiphysin (AMPH; 600418) SH3 domain, 4 transmembrane domains, intracellular N and C termini, and 2 putative phosphorylation sites. Western blot analysis showed that PRAF2 was expressed as a 19-kD protein, consistent with its calculated molecular mass, in all human tissues examined except testis. Strongest expression was detected in brain, small intestine, lung, spleen, and pancreas. Possible dimer formation and/or posttranslational modifications were observed in several tissues. By immunohistochemical analysis, Koomoa et al. (2008) found strong PRAF2 expression in Purkinje cells in human cerebellum, with more moderate expression in cells of the molecular and granular levels. Expression in human cerebral cortex, hippocampus, and lateral ventricles was restricted to neuronal cells. Immunoblot analysis showed expression of Praf2 in synaptic vesicles of rat brain.GENE FUNCTION
By coimmunoprecipitation analysis of transfected HEK293 cells, Schweneker et al. (2005) confirmed that JM4 interacted with CCR5. JM4 formed dimers and trimers with itself and heteromultimers with human and rat JWA in transfected cells. Schweneker et al. (2005) concluded that JM4 is a CCR5-interacting protein that may function in trafficking and membrane localization of CCR5 and other receptors. Using immunohistochemical analysis, Fo et al. (2006) showed that PRAF2 was overexpressed in human breast, colon, lung, and ovary cancer tissues compared with corresponding normal tissues. Using microarray analysis, Geerts et al. (2007) detected PRAF2 mRNA in most tumor types examined, with highest expression in pediatric neuroblastic tumors (see 256700). In neuroblastoma patients, PRAF2 expression correlated with higher patient age (greater than 1 year), poorer patient survival, higher stage tumors, and MYCN (164840) amplification. Immunofluorescence microscopy of neuroblastoma cells demonstrated localization of PRAF2 in cytoplasmic punctae, with weaker expression in nuclei and perinuclear regions. Treatment of neuroblastoma cells with cerulenin, a fungal metabolite, further increased PRAF2 expre ... More on the omim web site
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
June 20, 2017: Protein entry updated
Automatic update: comparative model was added.
March 16, 2016: Protein entry updated
Automatic update: OMIM entry 300840 was added.
Feb. 25, 2016: Protein entry updated
Automatic update: model status changed
Feb. 24, 2016: Protein entry updated
Automatic update: model status changed
Jan. 25, 2016: Protein entry updated
Automatic update: model status changed