Immunoglobulin-binding protein 1 (IGBP1)
The protein contains 339 amino acids for an estimated molecular weight of 39222 Da.
Associated to surface IgM-receptor; may be involved in signal transduction. Involved in regulation of the catalytic activity of the phosphatases PP2A, PP4 and PP6 by protecting their partially folded catalytic subunits from degradative polyubiquitination until they associate with regulatory subunits. (updated: March 4, 2015)
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.
- 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.
- 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.
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| Variant | Description |
|---|---|
| dbSNP:rs6625580 |
Biological Process
B cell activation
Negative regulation of apoptotic signaling pathway
Negative regulation of cysteine-type endopeptidase activity involved in apoptotic process
Negative regulation of protein dephosphorylation
Negative regulation of stress-activated MAPK cascade
Negative regulation of transcription by RNA polymerase II
Positive regulation of dephosphorylation
Positive regulation of transcription by RNA polymerase II
Regulation of dephosphorylation
Regulation of microtubule-based movement
Response to interleukin-1
Response to tumor necrosis factor
Signal transduction
The reference OMIM entry for this protein is 300139
Immunoglobulin-binding protein 1; igbp1
Protein phosphatase 2a, regulatory subunit alpha-4
Alpha-4
CLONING
The proliferation and differentiation of B cells is dependent upon a B-cell antigen receptor (BCR) complex. Binding of antigens to specific B-cell receptors results in a tyrosine phosphorylation reaction through the BCR complex and leads to multiple signal transduction pathways. The murine Igbp1 gene encodes a protein that coprecipitates with the MB1 (112205) protein of the BCR complex and has a possible SH3-binding motif and multiple sites that are phosphorylated by protein kinase C under phorbol myristate acetate activation (Inui et al., 1995). TAP42, a yeast gene similar to Igbp1, is associated with phosphatase 2A or Sit4, all of which are critical for the survival of yeast cells in the rapamycin-sensitive signal transduction pathways (Di Como and Arndt, 1996). Onda et al. (1997) demonstrated the existence of an Igbp1/TAP42-related gene in humans by Southern blot analysis with the mouse Igbp1 cDNA probe on a DNA zoo blot. They used the mouse probe to isolate 2 overlapping cDNA clones from a human B-cell line. The IGBP1 cDNA encodes a potential polypeptide of 339 amino acids with 82.9% amino acid sequence homology to mouse Igbp1. This putative protein contains 4 potential N-glycosylation sites, 2 myristylation sites, 6 possible phosphorylation sites with protein kinase C and 7 with casein kinase II, and an amino acid stretch related to the SH3-binding consensus sequence in a similar position to that found in mouse Igbp1 and yeast TAP42. By Northern blot analysis, Onda et al. (1997) detected ubiquitous expression of IGBP1 as a 1.4-kb mRNA, with highest levels of expression found in heart, skeletal muscle, and pancreas. Antibodies against an IGBP1 fusion protein detected a single band of 45 kD in Western blots from human lymphoid cell lines.GENE FUNCTION
Wildtype Mid1 (300552) colocalizes predominantly with microtubules, in contrast to mutant versions of Mid1 found in Opitz syndrome (300000) patients that appear clustered in the cytosol. Using yeast 2-hybrid screening, Liu et al. (2001) found that the alpha-4 subunit of protein phosphatases-2A, -4, and -6 bound Mid1. Localization of Mid1 and the alpha-4 subunit was influenced by one another in transiently transfected cells. Mid1 could recruit the alpha-4 subunit onto microtubules, and high levels of the alpha-4 subunit could displace Mid1 into the cytosol. Metabolic (32)P labeling of cells revealed Mid1 to be a phosphoprotein, and coexpression of the full-length alpha-4 subunit decreased Mid1 phosphorylation, indicative of a functional interaction. Association of GFP-Mid1 with microtubules in living cells was perturbed by inhibitors of MAP kinase activation. Liu et al. (2001) concluded that Mid1 association with microtubules, which seems important for normal midline development, is regulated by dynamic phosphorylation involving MAP kinase and protein phosphatase that is targeted specifically to Mid1 by the alpha-4 subunit. Kong et al. (2004) demonstrated that alpha-4 is required to repress apoptosis in mouse cells. Alpha-4 is a nonredundant regulator of the dephosphorylation of the transcription factors c-Jun and p53 (191170). As a result of alpha-4 deletion, multiple proapoptotic genes were transcribed. Either inhibition of new protein synthesis or Bcl-x(L) expression suppressed apoptosis initiated by alpha-4 deletion. Kong et al. (2004) concluded that mammalian cell viability depends on repression of transcription-initiated apoptosis mediated by a compon ... More on the omim web site
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 300139 was added.
Jan. 24, 2016: Protein entry updated
Automatic update: model status changed