Endophilin-B1 (SH3GLB1)
The protein contains 365 amino acids for an estimated molecular weight of 40796 Da.
May be required for normal outer mitochondrial membrane dynamics (PubMed:15452144). Required for coatomer-mediated retrograde transport in certain cells (By similarity). May recruit other proteins to membranes with high curvature. May promote membrane fusion (PubMed:11604418). Involved in activation of caspase-dependent apoptosis by promoting BAX/BAK1 activation (PubMed:16227588). Isoform 1 acts proapoptotic in fibroblasts (By similarity). Involved in caspase-independent apoptosis during nutrition starvation and involved in the regulation of autophagy. Activates lipid kinase activity of PIK3C3 during autophagy probably by associating with the PI3K complex II (PI3KC3-C2) (PubMed:17891140). Associated with PI3KC3-C2 during autophagy may regulate the trafficking of ATG9A from the Golgi complex to the peripheral cytoplasm for the formation of autophagosomes by inducing Golgi membrane tubulation and fragmentation (PubMed:21068542). Involved in regulation of degradative endocytic trafficking and cytokinesis, probably in the context of PI3KC3-C2 (PubMed:20643123). Isoform 2 acts antiapoptotic in neuronal cells; involved in maintenance of mitochondrial morphology and promotes neuronal viability (By similarity). (updated: Nov. 22, 2017)
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.
- 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.
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Biological Process
Apoptotic process
Autophagic cell death
Autophagy
Cellular response to amino acid starvation
Cellular response to glucose starvation
Membrane fission
Positive regulation of autophagosome assembly
Positive regulation of autophagy
Positive regulation of membrane tubulation
Positive regulation of protein oligomerization
Positive regulation of protein targeting to mitochondrion
Positive regulation of protein-containing complex assembly
Protein complex oligomerization
Protein localization to vacuolar membrane
Receptor catabolic process
Regulation of cytokinesis
Regulation of macroautophagy
Regulation of protein stability
Cellular Component
Autophagosome membrane
Cytoplasm
Cytoplasmic vesicle
Cytosol
Extracellular exosome
Golgi membrane
Midbody
Mitochondrial outer membrane
Protein-containing complex
Molecular Function
Cadherin binding
Identical protein binding
Lipid binding
Protein homodimerization activity
The reference OMIM entry for this protein is 609287
Sh3 domain, grb2-like, endophilin b1; sh3glb1
Endophilin b1
Bax-interacting factor 1; bif1
Kiaa0491
CLONING
Using BAX (600040) as bait in a yeast 2-hybrid screen of a skeletal muscle cDNA library, Pierrat et al. (2001) cloned SH3GLB1. The deduced 362-amino acid protein contains an N-terminal domain, a central coiled-coil region, and a C-terminal SH3 domain. SH3GLB1 shares 65% amino acid identity with SH3GLB2 (609288). Northern blot analysis detected a major 1.9-kb transcript and a minor 1.7-kb transcript in most tissues examined, with higher levels in heart, placenta, and skeletal muscle. Osteosarcoma and HeLa cells transfected with SH3GLB1 expressed the protein in the cytoplasm, but it was excluded from the nucleus. Cuddeback et al. (2001) cloned SH3GLB1, which they called BIF1, using BAX as bait in a yeast 2-hybrid screen of a brain cDNA library. The deduced protein contains 365 amino acids. Northern blot analysis revealed abundant expression in heart, skeletal muscle, kidney, and placenta. Transcripts of 1.5, 2.0, and 6.0 kb were detected. Fluorescence-tagged SH3GLB1 showed a cytoplasmic distribution, and a proportion of the protein associated with mitochondria. Modregger et al. (2003) cloned several variants of mouse Sh3glb1, which they called endophilin B1. The deduced proteins range from 365 to 386 residues in length. The N-terminal domain of endophilin B1 shares highest similarity with the lipid-binding and -modifying (LBM) domain of class A endophilins (see SH3GL2; 604465), which mediates lysophosphatidic acid (LPA) acyltransferase activity, liposome binding, and tubulation. Northern blot analysis detected transcripts of 2.6, 5.0, 6.5, and 8.0 kb that were generated by alternative splicing and the use of alternate polyadenylation signals. Two brain-specific transcripts, designated endophilins B1b and B1c, differ in the 3-prime exon 6 splice site. The ubiquitously expressed transcript, endophilin B1a, lacks exons 6 and 7. Western blot analysis detected a 40-kD protein in most mouse tissues, a 42-kD protein in brain only, and a 43-kD protein in lung and spleen only. Confocal microscopy detected epitope-tagged endophilin B1b in a reticular pattern throughout the cytoplasm. Endophilin B1b associated with membranes in fractionated mouse brain homogenates.GENE FUNCTION
Using SH3GLB1 truncation mutants, Pierrat et al. (2001) determined that the first 42 N-terminal amino acids of SH3GLB1, and not the SH3 domain, were required for its interaction with BAX, and a point mutation at val5 of SH3GLB1 abrogated the interaction. SH3GLB1 could form homodimers and heterodimers with SH3GLB2. Mutation analysis indicated that the coiled-coil region between amino acids 153 and 183 was required for homo- and heterodimer formation. SH3GLB1 overexpression in HeLa and human embryonic kidney cells had a general weak protective effect (5 to 10%) against cell death induced by BAX overexpression, FAS ligand (TNFSF6; 134638), and chemical agents. By yeast 2-hybrid analysis, Cuddeback et al. (2001) confirmed a direct interaction between SH3GLB1 and BAX. Immunoprecipitation analysis detected an endogenous interaction between Sh3glb1 and Bax in a mouse hematopoietic cell line. Induction of apoptosis by interleukin-3 (IL3; 147740) withdrawal increased the association of Bax with Sh3glb1, and this was accompanied by a conformational change in the Bax protein. Overexpression of Sh3glb1 promoted Bax conformational change, caspase activation, and apoptotic cell death in mouse hematopoietic cells following IL3 deprivation. Modregger et al. (20 ... 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
March 16, 2016: Protein entry updated
Automatic update: OMIM entry 609287 was added.
Feb. 24, 2016: Protein entry updated
Automatic update: model status changed