Dolichyl-diphosphooligosaccharide--protein glycosyltransferase subunit 2 (RPN2)
The protein contains 631 amino acids for an estimated molecular weight of 69284 Da.
Subunit of the oligosaccharyl transferase (OST) complex that catalyzes the initial transfer of a defined glycan (Glc(3)Man(9)GlcNAc(2) in eukaryotes) from the lipid carrier dolichol-pyrophosphate to an asparagine residue within an Asn-X-Ser/Thr consensus motif in nascent polypeptide chains, the first step in protein N-glycosylation. N-glycosylation occurs cotranslationally and the complex associates with the Sec61 complex at the channel-forming translocon complex that mediates protein translocation across the endoplasmic reticulum (ER). All subunits are required for a maximal enzyme activity. (updated: Dec. 5, 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 predicted to be membranous by TOPCONS.
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| Variant | Description |
|---|---|
| dbSNP:rs34951322 |
No binding partner found
Biological Process
Aging
Cellular protein modification process
Protein N-linked glycosylation
Protein N-linked glycosylation via asparagine
Response to drug
Viral protein processing
The reference OMIM entry for this protein is 180490
Ribophorin ii; rpn2
DESCRIPTION
The RPN2 gene encodes ribophorin II, which is involved in ribosome binding. Ribophorin I (RPN1; 180470) and RPN2 are abundant, highly conserved glycoproteins located exclusively in the membranes of the rough endoplasmic reticulum (Crimaudo et al., 1987).CLONING
Using probes derived from a human liver expression library, Crimaudo et al. (1987) isolated and sequenced full-length human cDNA clones encoding ribophorins I and II. The cDNA clones hybridized to mRNA species of 2.5 kb and encoded polypeptides of 68.5 and 69.3 kD, respectively. Sequence comparisons and immunoblotting with specific antibodies showed both proteins to be highly conserved throughout a variety of species. However, no relationship between the 2 proteins could be deduced from their primary sequences.MAPPING
Using cDNAs in the study of a panel of somatic cell hybrids, Barton et al. (1987) mapped RPN2 to chromosome 20. Loffler et al. (1991) mapped the RPN2 gene to 20q12-q13.1 by in situ hybridization.GENE FUNCTION
Kelleher et al. (1992) reported that mammalian oligosaccharyltransferase activity is associated with a protein complex composed of ribophorin I, ribophorin II, and a 48-kD oligosaccharyltransferase protein (602202). Among 44 women with breast cancer (114480), Honma et al. (2008) observed a significant association (p = 0.0052) between increased expression of RPN2 in cancer tissue and decreased clinical response to the antimicrotubule chemotherapeutic agent docetaxel. Small interfering RNA (siRNA) targeting RPN2 significantly promoted docetaxel-dependent apoptosis and cell growth inhibition of docetaxel-resistant human breast cancer cells in vitro. In vivo atelocollagen delivery of RPN2 siRNA significantly reduced drug-resistant tumor growth in mice given docetaxel. Further studies indicated that RPN2 conferred drug resistance via increased glycosylation of P-glycoproteins. Honma et al. (2008) concluded that RPN2 siRNA introduction may hypersensitize cancer cell responses to chemotherapeutic agents. ... More on the omim web site
June 30, 2020: Protein entry updated
Automatic update: OMIM entry 180490 was added.
Dec. 9, 2018: Protein entry updated
Automatic update: Entry updated from uniprot information.
Oct. 19, 2018: Additional information
Initial protein addition to the database. This entry was referenced in Bryk and co-workers. (2017).