C3orf70

C3orf70 also known as Chromosome 3 Open Reading Frame 70, is a 250aa protein in humans that is encoded by the C3orf70 gene. The protein encoded is predicted to be a nuclear protein; however, its exact function is currently unknown.^[1] C3orf70 can be identified with known aliases: Chromosome 3 Open Reading Frame 70, AK091454, UPF0524, and LOC285382.^[1][2]

Gene

In humans, C3orf70 is located on the reverse strand of Chromosome 3 at 3q27.2 (see Figure 1).^[5] This identifies its location starting 184,795,838 base pairs and ending 184,870,802 base pairs from PTER, the terminus of the short arm, on chromosome 3. C3orf70 spans 74,964 bases containing two exons and two introns.

mRNA

The transcribed mRNA is a 5,901 base pair transcript. C3orf70 consists of one known splice variant with two exons of 388 base pairs and 5,512 base pairs respectively (see Figure 2); location of junction occurs at 67aa[C].^[1] A single 5’ cap and three possible 3’ polyadenylation signals have been identified.^[1]

Protein

Composition

The translated protein is a 250 amino acid product. The precursor protein has been predicted with a molecular weight of 27.8kdal and an isoelectric point of 4.67.^[6] With 33 serines and 8 glysines, the C3orf70 protein is both Serine rich and Glycine poor.^[6]

Domains

C3orf70 protein has no known signal peptides or domains.

Homology

C3orf70 has no known paralogs in humans; however C3orf70 has conserved homologs, see Figure 3. Highly conserved across species excluding invertebrates, plants, fungi, and bacteria, C3orf70 shows a moderate rate of evolution, see Figure 4 and 5.^[7]

• 

  Figure 3: Compiled data for select orthologs of C3orf70 across species

• 

  Figure 4: C3orf70 Homolog Protein Divergence from Homo sapiens. Color identification specific to species (shown in Figure 3). Time of divergence calculated by timetree.org. Non-identity calculated based on (1-NCBI sequence identity).

• 

  Figure 5: Divergence rate of C3orf70 with respect to Cytochrome C and Fibrinogen displaying a moderate to slow rate of divergence.

Regulation

Transcription

Promoter

There is only one known promoter predicted by Genomatix for the C3orf70 protein located on the minus strand of chromosome 3 at location 184870702-184871302bp, therefore identified as 600bp in length.^[8] High mammalian conservation was observed for the identified promoter sequence.

Transcription factors

Figure 6: Generated list of a selection of transcription factor binding sites in the C3orf70 promoter

Through the use of Genomatix, a table was generated of the top 20 transcription factors and their binding sites in the C3orf70 promoter (see Figure 6).^[8]

Translation

Post-translational modifications

Utilizing NetPhos, a total of 25 phosphorylation sites have been predicted (20 Serines, 3 Threonines, and 2 Tyrosines) which occur throughout the protein indicating an intracellular localization.^[9] Figure 7 pinpoints the location of the 25 potential phosphorylation sites. Additionally, two N-myrisolation sites were predicted at amino acid position 40-45 and 210-215 indicating a possible N-terminus and C-terminus membrane anchor region.^[10] There are also 28 potential missense mutations in the human C3orf70.^[11]

Subcellular localization

PSORT II indicates the subcellular localization of C3orf70 is in the nucleus.^[12] In addition to this, following SDSC's Biology Workbench's SAPS kNN-Prediction, the C3orf70 protein for humans has a 60.9% likelihood to end up in the nuclear region of a cell, as determined by the amino acid make-up of C3orf70.^[6] Homologs including chimp, mouse, alligator, and zebrafish conclude the same nuclear region with a >60% likelihood.^[12] A nuclear localization site has not been identified in the C3orf70 sequence.

Expression

From Unigene's EST cDNA tissue abundance display (see Figure 8), C3orf70 is non-ubiquitously expressed and has relatively low expression levels with slightly higher expression levels seen in the brain.^[13] Also, microarray data profile GDS426 (see Figure 9) showing the expression of C3orf70 across normal tissues displays a notably high presence in the brain, spinal cord, and prostate tissue.^[14]

Function and Further Reading

The function of C3orf70 is unknown. It is suggested to be a nuclear protein that plays a role in neurological development. Additional avenues of research pertaining to the C3orf70 gene include:

There is a patent that identified genes associated with midbrain dopamine neurons for engraftment by looking at the differentiation of hESC and/or hiPSC in floor plate midbrain progenitor cells. C3orf70 was found to have a fold-change of 2.45, which was not determined significant in experimentation ^[15]

A publication was discovered through multiple sources that linked the C3orf70 gene to a “Genome-wide association study of major depressive disorder”.^[16]

A microdeletion has been identified from 3q26.33-3q27.2.^[17] Mandrille et al. associates this discovered microdeletion with a possible clinical syndrome characterized by clinical features related to brain development.

References