La-related protein 1 (LARP1)
The protein contains 1096 amino acids for an estimated molecular weight of 123510 Da.
RNA-binding protein that regulates the translation of specific target mRNA species downstream of the mTORC1 complex, in function of growth signals and nutrient availability (PubMed:20430826, PubMed:23711370, PubMed:24532714, PubMed:25940091, PubMed:28650797, PubMed:28673543, PubMed:29244122). Interacts on the one hand with the 3' poly-A tails that are present in all mRNA molecules, and on the other hand with the 7-methylguanosine cap structure of mRNAs containing a 5' terminal oligopyrimidine (5'TOP) motif, which is present in mRNAs encoding ribosomal proteins and several components of the translation machinery (PubMed:23711370, PubMed:25940091, PubMed:28650797, PubMed:29244122, PubMed:26206669, PubMed:28379136). The interaction with the 5' end of mRNAs containing a 5'TOP motif leads to translational repression by preventing the binding of EIF4G1 (PubMed:25940091, PubMed:28650797, PubMed:29244122, PubMed:28379136). When mTORC1 is activated, LARP1 is phosphorylated and dissociates from the 5' untranslated region (UTR) of mRNA (PubMed:25940091, PubMed:28650797). Does not prevent binding of EIF4G1 to mRNAs that lack a 5'TOP motif (PubMed:28379136). Interacts with the free 40S ribosome subunit and with ribosomes, both monosomes and polysomes (PubMed:20430826, PubMed:24532714, PubMed:25940091, PubMed:28673543). Under normal nutrient availability, interacts primarily with the 3' untranslated region (UTR) of mRNAs encoding ribosomal proteins and increases protein synthesis (PubMed: (updated: May 8, 2019)
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.
- 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.
- 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
Cell population proliferation
Cellular response to rapamycin
MRNA stabilization
Negative regulation of translation
Negative regulation of translational initiation
Positive regulation of macroautophagy
Positive regulation of translation
Positive regulation of translational initiation
Positive regulation of viral genome replication
Posttranscriptional regulation of gene expression
Response to amino acid starvation
TOR signaling
TORC1 signaling
Translational initiation
The reference OMIM entry for this protein is 612059
La ribonucleoprotein domain family, member 1; larp1
La-related protein; larp
Kiaa0731
CLONING
By sequencing clones obtained from a size-fractionated human brain cDNA library, Nagase et al. (1998) cloned LARP1, which they designated KIAA0731. The deduced protein contains 1,096 amino acids. RT-PCR ELISA detected high LARP1 expression in all tissues examined, with highest level in heart. Chauvet et al. (2000) cloned fly and mouse Larp, and they identified orthologs in several species. All LARP proteins, including human LARP, contain 2 conserved regions. The first conserved region shares homology with La proteins (see SSB; 109090) from various species, whereas the second conserved region is restricted to LARP proteins. In situ hybridization of mouse embryos showed expression of Larp in dorsal root ganglia and spinal cord, as well as in developing organs characterized by epithelial-mesenchymal interactions.MAPPING
By radiation hybrid analysis, Nagase et al. (1998) mapped the LARP1 gene to chromosome 10. However, Hartz (2008) mapped the LARP1 gene to chromosome 5q33.2 based on an alignment of the LARP1 sequence (GenBank GENBANK AB018274) with the genomic sequence (build 36.1). ... More on the omim web site
May 11, 2019: Protein entry updated
Automatic update: Entry updated from uniprot information.
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 612059 was added.