Ephrin-B1 (EFNB1)
The protein contains 346 amino acids for an estimated molecular weight of 38007 Da.
Cell surface transmembrane ligand for Eph receptors, a family of receptor tyrosine kinases which are crucial for migration, repulsion and adhesion during neuronal, vascular and epithelial development (PubMed:8070404, PubMed:7973638). Binding to Eph receptors residing on adjacent cells leads to contact-dependent bidirectional signaling into neighboring cells (PubMed:8070404, PubMed:7973638). Shows high affinity for the receptor tyrosine kinase EPHB1/ELK (PubMed:8070404, PubMed:7973638). Can also bind EPHB2 and EPHB3 (PubMed:8070404). Binds to, and induces collapse of, commissural axons/growth cones in vitro (By similarity). May play a role in constraining the orientation of longitudinally projecting axons (By similarity). (updated: Dec. 5, 2018)
Protein identification was indicated in the following studies:
- 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 annotated as membranous in Gene Ontology, is annotated as membranous in UniProt, is predicted to be membranous by TOPCONS.
Biological Process
Axon guidance
Cell adhesion
Cell-cell signaling
Embryonic pattern specification
Ephrin receptor signaling pathway
Neural crest cell migration
Positive regulation of T cell proliferation
T cell costimulation
The reference OMIM entry for this protein is 300035
Ephrin b1; efnb1
Eph-related receptor tyrosine kinase ligand 2; eplg2
Ligand of eph-related kinase 2; lerk2
Efl3
DESCRIPTION
See 179610 for background information on ephrins and the Eph family of receptor protein-tyrosine kinases. The EFNB1 gene encodes a ligand of ELK (EPHB1; 600600) that is highly conserved among rat, mouse, and human.GENE FUNCTION
Bohme et al. (1996) presented evidence that LERK2 is a functional ligand of the EPH-related kinase HEK2 (EPHB3; 601839). They reported that coincubation of HEK2- and LERK2-expressing cells induces cell-cell adhesion and aggregation. Palmer et al. (2002) showed that SRC family kinases, or SFKs (see SRC; 190090), are positive regulators of ephrin-B phosphorylation and phosphotyrosine-mediated reverse signaling. EphB receptor engagement of ephrin-B caused rapid recruitment of SFKs to ephrin-B expression domains and transient SFK activation. With delayed kinetics, ephrin-B ligands recruited the cytoplasmic PDZ domain-containing protein tyrosine phosphatase PTPBL (see 600267) and were dephosphorylated. These data suggested the presence of a switch mechanism that allows a shift from phosphotyrosine-/SFK-dependent signaling to PDZ-dependent signaling. Batlle et al. (2002) showed that beta-catenin (116806) and TCF (see TCF7L2; 602228) inversely control the expression of the EphB2 (600997)/EphB3 receptors and their ligand, ephrin B1, in colorectal cancer and along the crypt-villus axis. Disruption of EphB2 and EphB3 genes revealed that their gene products restrict cell intermingling and allocate cell populations within the intestinal epithelium. In EphB2/EphB3 null mice, the proliferative and differentiated populations intermingled. In adult EphB3 -/- mice, Paneth cells did not follow their downward migratory path, but scattered along crypt and villus. The authors concluded that, in the intestinal epithelium, beta-catenin and TCF couple proliferation and differentiation to the sorting of cell populations through the EphB/ephrin B system. Moore et al. (2004) studied the role of FGF and ephrin signaling in retina development in the frog. Activation of Fgfr2 (176943) signaling before gastrulation repressed cellular movements in the presumptive anterior neural plate and prevented normal retinal progenitor cells from adopting retinal fates. Ephrin B1 signaling during gastrulation was required for retinal progenitors to move into the eye field, and this movement could be modified by activating the FGF pathway. Moore et al. (2004) concluded that FGF modulation of ephrin signaling is important for establishing the bona fide retinal progenitors in the anterior neural plate. Egawa et al. (2003) examined the expression of B class ephrins-Ephs in the human ovary during corpus luteum formation, a process of tissue remodeling accompanied by angiogenesis. RT-PCR analysis detected mRNA of ephrins B1 and B2 (600527) and EPHB1 (600600), EPHB2, and EPHB4 (600011) in human corpora lutea of the early luteal phase. After ovulation, a rapid increase in ephrin B1 expression was observed on luteinizing granulosa cells, whereas its expression on luteinizing theca interna cells decreased. The authors concluded that ephrin B1-expressing granulosa cells can directly interact with Eph-bearing cells during corpus luteum formation in vivo, suggesting that Eph-ephrin system is involved in this process. Bong et al. (2007) found that vertebrate ephrin B1 interacted with Stat3 (102582) in a tyrosine phosphorylation-dependent manner, resulting in phosphorylation and enhanced transcriptional activation of Stat3. Using Xenopu ... More on the omim web site
Dec. 9, 2018: Protein entry updated
Automatic update: Entry updated from uniprot information.
Nov. 17, 2018: Protein entry updated
Automatic update: OMIM entry 300035 was added.
Oct. 19, 2018: Additional information
Initial protein addition to the database. This entry was referenced in Bryk and co-workers. (2017).