Ragulator complex protein LAMTOR2 (LAMTOR2)
The protein contains 125 amino acids for an estimated molecular weight of 13508 Da.
As part of the Ragulator complex it is involved in amino acid sensing and activation of mTORC1, a signaling complex promoting cell growth in response to growth factors, energy levels, and amino acids. Activated by amino acids through a mechanism involving the lysosomal V-ATPase, the Ragulator functions as a guanine nucleotide exchange factor activating the small GTPases Rag. Activated Ragulator and Rag GTPases function as a scaffold recruiting mTORC1 to lysosomes where it is in turn activated. Adapter protein that enhances the efficiency of the MAP kinase cascade facilitating the activation of MAPK2. (updated: Sept. 12, 2018)
Protein identification was indicated in the following studies:
- 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.
This protein is annotated as membranous in Gene Ontology.
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Biological Process
Activation of MAPKK activity
Cell cycle arrest
Cellular protein localization
Cellular response to amino acid starvation
Cellular response to amino acid stimulus
Fibroblast migration
MAPK cascade
Neutrophil degranulation
Positive regulation of TOR signaling
Protein localization to cell junction
Regulation of cell growth
Regulation of cell-substrate junction organization
Regulation of macroautophagy
The reference OMIM entry for this protein is 610389
Late endosomal/lysosomal adaptor, mapk and mtor activator 2; lamtor2
Mapbp-interacting protein; mapbpip
P14
CLONING
Using gradient centrifugation, followed by 2-D gel electrophoresis and peptide sequencing, Wunderlich et al. (2001) identified mouse Mapbpip, which they called p14. The 125-amino acid mouse protein has a predicted molecular mass of 13.5 kD. By database analysis, they identified highly conserved homologs in human, rat, cow, chicken, and Drosophila. Northern blot analysis identified ubiquitous expression of a 700-bp mouse transcript. Proteinase K digestion and a variety of immunofluorescence assays suggested a peripheral association of p14 with the cytoplasmic face of late endosomes/lysosomes in a variety of cell types.GENE FUNCTION
Using yeast 2-hybrid, GST pull-down, and coimmunoprecipitation analysis, Wunderlich et al. (2001) showed that Mp1 (MAP2K1IP1; 603296), a scaffold protein of the mitogen-activated protein kinase pathway, interacted with p14. Mp1 and p14 colocalized to the same perinuclear compartment, and expression of recombinant p14 targeted to the plasma membrane caused Mp1 to mislocalize to the plasma membrane as well. GST pull-down assays on proteins expressed in vitro demonstrated that Erk2 (MAPK1; 176948) bound to Mp1 and p14. In vivo assays showed that p14, MEK1 (MAP2K1; 176872), and Mp1 coimmunoprecipitated together.MAPPING
The International Radiation Hybrid Mapping Consortium mapped the MAPBPIP gene to chromosome 1 (TMAP RH45081).MOLECULAR GENETICS
In a Caucasian Mennonite family with a primary immunodeficiency syndrome (610798), Bohn et al. (2007) combined results of genetic linkage analysis and genomewide transcriptional profiling analysis and found that MAPBPIP was the only gene located within the crucial region on chromosome 1q21 that was underexpressed by a factor greater than 2 in affected individuals. Sequence analysis revealed that affected individuals were homozygous for a mutation in the 3-prime UTR of exon 4 (610389.0001) that was not found in 100 control alleles or in 34 alleles from healthy Mennonites. Studies in MAPBPIP-deficient cells showed severely perturbed distribution of late endosomes, suggesting a role for MAPBPIP in endosomal biogenesis. ... More on the omim web site
Nov. 17, 2018: Protein entry updated
Automatic update: OMIM entry 610389 was added.
Oct. 19, 2018: Additional information
Initial protein addition to the database. This entry was referenced in Bryk and co-workers. (2017).