Leucine-rich alpha-2-glycoprotein (LRG1)
The protein contains 347 amino acids for an estimated molecular weight of 38178 Da.
No function (updated: Sept. 12, 2018)
Protein identification was indicated in the following studies:
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:rs7251081 | |
| dbSNP:rs966384 |
No binding partner found
Biological Process
Brown fat cell differentiation
Neutrophil degranulation
Positive regulation of angiogenesis
Positive regulation of endothelial cell proliferation
Positive regulation of transforming growth factor beta receptor signaling pathway
Response to bacterium
The reference OMIM entry for this protein is 611289
Leucine-rich alpha-2-glycoprotein 1; lrg1
Lrg
DESCRIPTION
The leucine-rich repeat (LRR) family of proteins, including LRG1, have been shown to be involved in protein-protein interaction, signal transduction, and cell adhesion and development. LRG1 is expressed during granulocyte differentiation (O'Donnell et al., 2002).CLONING
Human LRG1 was isolated from human serum by Haupt and Baudner, 1977. By sequence analysis, Takahashi et al. (1985) determined that purified LRG1 protein has 312 amino acids and an experimentally determined molecular mass of 45 kD. The LRG1 polypeptide contains 1 galactosamine and 4 glucosamine oligosaccharides attached and has 2 intrachain disulfide bonds. Leucine comprises 66 of the 312 amino acids, and LRG1 contains at least 8 24-amino acid leucine-rich repeats. Using cDNA representational difference analysis (RDA) to identify genes induced during neutrophilic differentiation of GCSF (CSF3; 138970)-responsive murine myeloid precursor 32DCL3G cells, followed by database analysis, O'Donnell et al. (2002) identified mouse and human LRG1. The deduced 347-amino acid human protein shares 66% amino acid identity with its mouse homolog. LRG1 contains a predicted N-terminal signal peptide, and the mature peptide is identical to the sequence identified by Takahashi et al. (1985). Northern blot analysis of adult mouse tissues detected high Lrg1 expression in liver, much lower levels in heart, and barely detectable expression in lung and spleen. Lrg1 was not detected in brain, skeletal muscle, kidney, or testis. Using human bone marrow and peripheral blood samples, O'Donnell et al. (2002) detected LRG1 expression in the neutrophil fraction of both bone marrow and peripheral blood and in the bone marrow mononuclear cell fraction.GENE FUNCTION
By Northern blot analysis of mouse Lrg1 expression during GCSF-induced granulocytic differentiation of 32DCL3G cells, O'Donnell et al. (2002) observed expression as early as 16 hours after GCSF induction, with expression reaching an 80-fold increase in 5 days. Comparison of the time course of Lrg1 induction to that of other genes upregulated during neutrophilic granulocyte differentiation suggested that Lrg1 expression is an early event in the process. DMSO-induced granulocytic differentiation of human promyelocytic leukemia HL-60 cells was associated with upregulation of LRG1 expression. Increased LRG1 expression was also detected in GCSF-treated human cells derived from a patient with myeloproliferative disorder. In contrast, decreased LRG1 expression was detected after PMA treatment and induction of monocytic differentiation of HL-60 cells. Wang et al. (2013) identified upregulation of Lrg1 in the transcriptome of retinal microvessels isolated from mouse models of retinal disease that exhibit vascular pathology. The authors showed that in the presence of transforming growth factor-beta-1 (TGFB1; 190180), Lrg1 is mitogenic to endothelial cells and promotes angiogenesis. Mice lacking Lrg1 developed a mild retinal vascular phenotype but exhibited a significant reduction in pathologic ocular angiogenesis. Lrg1 bound directly to the Tgf-beta accessory receptor endoglin (131195), which, in the presence of TGF-beta-1, resulted in promotion of the proangiogenic Smad1/5/8 signaling pathway (see 603295). Lrg1 antibody blockade inhibited this switch and attenuated angiogenesis. Wang et al. (2013) concluded that these studies revealed that LRG1 is a regulator of angiogenesis that mediates its effect by mod ... More on the omim web site
June 30, 2020: Protein entry updated
Automatic update: OMIM entry 611289 was added.
Oct. 19, 2018: Additional information
Initial protein addition to the database. This entry was referenced in Bryk and co-workers. (2017).