OSER1

Gene

OSER1 a valid, protein coding gene that is found on the minus strand of chromosome 20 at q13.12 by searching the UCSC Genome Browser, but q13.11 according to Refseq on NCBI.

Gene neighborhood

A few of the known genes near OSER1 are given in the box below with their known function.

Transcript

General properties

• Genomic DNA Length:14,968 base pairs (bp)
• Most common mRNA Length: 2,260 bp with 4 exons. Has 10 splice isoforms.
• 5' untranslated region 252 bp long.
• 3' untranslated region 1,129 bp long.

Transcript variants

10 splice isoforms that encode good proteins, altogether 8 different isoforms, 2 of which are complete isoforms. The image below shows the 10 isoforms that are predicted. Of these 10 splice isoforms, 8 have varying peptide lengths, however all of these proteins are only hypothetical with no extensive research done on them.

Transcription regulation

When looking at the predicted promoter sequence, there are no RNA Polymerase II binding sites, however there is a binding site for core promoter element for TATA-less promoters. In this same region of the promoter, there is also a TATA-binding factor sequence, which helps in the positioning of RNA polymerase II for transcription.

Protein

General properties

• Contains a highly conserved domain of unknown function 776 (DUF776), which composes 62% of the entire protein.
• Molecular weight 31.8 kilodaltons
• Isoelectric point 8.57
• Predicted to be a nuclear protein

Function

The function of OSER1 is not well understood by the scientific community in general. It does contain a domain of unknown function, DUF776, which has a large segment that is well conserved from Caenorhabditis elegans to humans. Its expression is increased in rat cardiomyocytes undergoing hydrogen peroxide induced apoptosis. It has also been shown that its overexpression extends lifespan in silkworms, nematodes, and flies, while its depletion correspondingly shortens lifespan. This effect might be due to its regulation of mitochondrial biology and oxidative stress. Moreover, it promotes reproduction in animal models and is associated with human reproduction and longevity.

Expression

When looking at the EST Profiles in humans, normal tissue (non-cancerous), expresses at a level of 82 transcripts per million. OSER1 has been shown to increase in expression in rat cardiac myocytes undergoing |H|2|O|2|-induced apoptosis, suggesting a role in cell death. In bladder, cervical, head and neck, non-neoplasia, pancreatic, and prostate cancer cells, there are expression levels lower than normal.

Homology

OSER1 gene has no clear paralogs in the human genome. However, it has many orthologs in other organisms, and is conserved highly in organisms such as Xenopus tropicalis and is semi-conserved in the proto-animal Trichoplax adherens at the C-terminus.

The following table presents a select number of the orthologs found.

Conservation

The image below is a multiple sequence alignment comparing the conservation of the OSER1 protein amongst other organisms. The protein is highly conserved in the DUF776 region amongst vertebrates, and also at the C-terminus in eukaryotes.

Predicted post-translational modification

Using tools at ExPASy the following are predicted post-translational modifications for OSER1.

• Predicted propeptide cleavage site in protein between position R81 and S82.
• 30 predicted Serine phosphorylation sites
• 5 predicted Threonine phosphorylation sites
• 3 predicted Tyrosine phosphorylation sites

Predicted secondary structure

PELE (Protein Secondary Structure Prediction) was used to predict the secondary structure of OSER1. There is little in the way of β-strand or α-helix secondary structure, but a large part of the protein appears to exist as random coils. This is shown on the image of the OSER1 images to the right.

References

References

1. {{EntrezGene. 51526: C20orf111 chromosome 20 open reading frame 111
2. [https://www.genecards.org/cgi-bin/carddisp.pl?gene=C20orf111&search=perit1/ Genecards]
3. (2001). "The DNA sequence and comparative analysis of human chromosome 20". Nature.
4. [http://genome.brc.mcw.edu/cgi-bin/hgBlat UCSC Genome Search]{{dead link. (February 2018)
5. (February 1993). "Chromosome 20 long arm deletion in an elderly malformed man". J. Med. Genet..
6. [http://genome.brc.mcw.edu/cgi-bin/hgBlat BLAT Search Genome]
7. (December 2011). "Junctophilin 1 and 2 proteins interact with the L-type Ca2+ channel dihydropyridine receptors (DHPRs) in skeletal muscle". J. Biol. Chem..
8. (2012). "Differential Epigenetic Regulation of TOX Subfamily High Mobility Group Box Genes in Lung and Breast Cancers". PLOS ONE.
9. (February 1985). "Adenosine deaminase: characterization and expression of a gene with a remarkable promoter". EMBO J..
10. [https://www.ncbi.nlm.nih.gov/nuccore/NM_016470.7 NCBI (National Center for Biotechnology Information)]
11. [https://www.ncbi.nlm.nih.gov/IEB/Research/Acembly/av.cgi?db=human&term=Perit1&submit=Go AceView]
12. (July 2025)
13. (March 2007). "The new core promoter element XCPE1 (X Core Promoter Element 1) directs activator-, mediator-, and TATA-binding protein-dependent but TFIID-independent RNA polymerase II transcription from TATA-less promoters". Mol. Cell. Biol..
14. [[TATA-binding protein. Wikipedia:TATA-binding Protein]]
15. [http://workbench.sdsc.edu/ SDSC Biology Workbench 2.0]
16. "PSORTII Prediction".
17. Song, Jiangbo. (2024-08-21). "FOXO-regulated OSER1 reduces oxidative stress and extends lifespan in multiple species". Nature Communications.
18. (April 2007). "Cardiac myocyte gene expression profiling during H2O2-induced apoptosis". Physiol. Genomics.
19. "EST Profile - Hs.75798". National Center for Biotechnology Information.
20. [https://blast.ncbi.nlm.nih.gov/Blast.cgi NCBI BLAST: Basic Local Alignment Search Tool]
21. [http://www.expasy.org/ ExPASy Proteomics Server]
22. (November 2009). "Incorporating support vector machine for identifying protein tyrosine sulfation sites". J Comput Chem.
23. (December 1999). "Sequence and structure-based prediction of eukaryotic protein phosphorylation sites". J. Mol. Biol..