Translocation protein SEC62 (SEC62)
The protein contains 399 amino acids for an estimated molecular weight of 45862 Da.
Mediates post-translational transport of precursor polypeptides across endoplasmic reticulum (ER). Proposed to act as a targeting receptor for small presecretory proteins containing short and apolar signal peptides. Targets and properly positions newly synthesized presecretory proteins into the SEC61 channel-forming translocon complex, triggering channel opening for polypeptide translocation to the ER lumen. (updated: Oct. 10, 2018)
Protein identification was indicated in the following studies:
- 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.
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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No binding partner found
Biological Process
Cotranslational protein targeting to membrane
Posttranslational protein targeting to endoplasmic reticulum membrane
Posttranslational protein targeting to membrane, translocation
The reference OMIM entry for this protein is 602173
Sec62, s. cerevisiae, homolog of; sec62
Translocation protein 1, drosophila, homolog of; tloc1
Htp1
CLONING
The translocation of secretory proteins across the endoplasmic reticulum membrane is mediated in yeast by Sec62 and other proteins. Daimon et al. (1997) cloned a gene, which they termed HTP1, that is the human homolog of Sec62. The HTP1 cDNA encodes a 399-amino acid polypeptide that is 28% identical to Sec62 and 36% identical to the Drosophila Sec62 homolog, Dtrp1. Northern blot analysis revealed RNAs of about 2.8 kb and 5.5 kb expressed concomitantly at varying levels in all tissues tested. By searching databases for sequences similar to yeast Sec62, followed by PCR of a HeLa cell cDNA library and RACE of a fetal brain cDNA library, Meyer et al. (2000) cloned SEC62. The deduced protein has 2 membrane-spanning segments. Western blot analysis detected Sec62 in all bovine and rat tissues examined. Immunofluorescence analysis of human hepatoma cells indicated that SEC62 and SEC63 (608648) colocalized with endoplasmic reticulum proteins.GENE FUNCTION
By Western blot analysis and coimmunoprecipitation of proteins from bovine rough microsomes, Meyer et al. (2000) found that mammalian Sec62 associated with Sec63 and Sec61 (see 609213). Cross-linking experiments indicated that Sec62 specifically interacted with the beta subunit of the Sec61 complex. Using mutation analysis with protein pull-down assays, Muller et al. (2010) found that the isolated N-terminal domain of human SEC62 (SEC62N) interacted directly with the 26 C-terminal amino acids of SEC63 in a 1:1 ratio. SEC62N also interacted specifically with the 60S ribosomal subunit in canine pancreatic ribosomes, a function not observed with SEC62 orthologs in invertebrates, yeast, and plants. Interaction of SEC62N with ribosomes was sensitive to salt and RNase treatment. Competition studies revealed that SEC62N and the ribosomal tunnel exit-interacting protein ERJ1 (DNAJC1; 611207) competed for an overlapping binding site on ribosomes. Muller et al. (2010) concluded that SEC62 and SEC63, like ERJ1, localize at the ribosomal tunnel exit and function in the transport of polypeptides into the ER.MAPPING
Hartz (2011) mapped the SEC62 gene to chromosome 3q26.2 based on an alignment of the SEC62 sequence (GenBank GENBANK BX648539) with the genomic sequence (GRCh37). ... More on the omim web site
June 30, 2020: Protein entry updated
Automatic update: OMIM entry 602173 was added.
Dec. 10, 2018: Protein entry updated
Automatic update: model status changed
Oct. 19, 2018: Additional information
Initial protein addition to the database. This entry was referenced in Bryk and co-workers. (2017).