Chromosome 20 open reading frame 85
# Chromosome 20 open reading frame 85

Chromosome 20 open reading frame 85, or most commonly known as C20orf85 is a gene that encodes for the C20orf85 Protein (UniProt ID: Q9H1P6) . This gene is not yet well understood by the scientific community.

## Background

### Aliases

* LLC1 - Low in Lung Cancer 1
* bA196N14.1

### Location

It is found on chromosome 20, more specifically 20q13.32. It runs in the 5' to 3' direction on the top strand of chromosome 20. The gene HSPD1P19 or Heat Shock Protein Family D Member 1 Pseudogene 19 neighbors the gene, running before C20orf85, from the 5' to 3' end.

## RNA

mRNA C20orf85 has 805 nucleotides which encodes for the C20orf85 protein. So far this is the only known gene variant as of June 2022 and contains 4 exons. It has also been found to be expressed in samples of the testis, endometrium, and liver from HPA RNA-seq normal tissues.

## Protein

This protein contains 137 Amino acids and is most commonly called “uncharacterized protein C20orf85,” or pfam14945. It has an approximate molecular weight of 15.5 kDa with an isoelectric point of 8.72. C20orf85 protein is rich in the amino acids tryptophan and proline, compared to other human proteins.

## Structure

According to iTasser and AlphaFold, the C20orf85 protein structure is predicted to have many more helices than sheets.

## Protein Level Regulation

The C20orf85 protein is predicted to be found in the extracellular space or the cytoplasm, per PSORTII, DeepLoc 1.0, and DeepLoc 2.0. It is tissue specific, being expressed in the lungs, trachea, testis, and ovary. There are also 3 predicted sites of SUMOylation and phosphorylation.

## Evolution

C20orf85 is predicted to evolve at a moderate pace, slower than the known fast evolving protein Fibrinogen Alpha but faster than the known slow evolving protein Cytochrome C.

### Paralog

Protein C20orf85 is paralogous with protein c2orf50. The two human proteins have been estimated to diverge from each other around 750 million years ago.

### Orthologs

C20orf85 has vast amounts of orthologs including mammals, reptiles, and birds. The table to the right shows a wide range of orthologs chosen because of the type of animal they were and the sequence identity.

## Interacting Proteins

C20orf85 has many interacting proteins, the proteins below were included because of their association to diseases and similarity in localization with C20orf85.

| Abbreviated name | Full name | Basis of identification AND What does it do? | Additional notes |
| - | - | - | - |
| MD2L2 | Mitotic spindle assembly checkpoint protein MAD2B | 2 hybrid prey Adapter protein that interacts with various proteins | Nucleus and cytoplasm localization and is ubiquitously expressed Fanconi anemia disease |
| FHL2 | Four and a half LIM domains protein 2 | Two hybrid prey | Localized in the cytoplasm and nucleus Many associated diseases |
| ALKBH7 | Alpha-ketoglutarate-dependent dioxygenase alkB homolog 7, mitochondrial | Validated 2 hybrid A protein hydroxylase and isrequired to induce programmed necrosis | Mitochondrion matrix but expressed in the ovary, like c20orf85 No likely diseases |
| CNOT2 | Trsncription complex subunit 2 | 2 Hybrid Various cellular processes, esp in translation | Localization in the cytoplasm and nucleus Involved in IDNADFS |
| CABP2 | Calcium binding protein 2 | 2 Hybrid Required for the inner hair cells of the ear | Localized in cytoplasm, cell membrane and golgi apparatus Involved in autosomal recessive deafness |

## Clinical Significance

Research conducted by Kyeong-Man Hong discovered that there is an inactivation of LLC1 (C20orf85) in some patients with non-small cell lung cancer but the reason for this is currently unknown. The research titled "Immunohistochemical localization of LLC1 in human tissues and its limited expression in non-small cell lung cancer" found expression in the lung but no further findings have been evaluated from that article.

### Mutations

There are many mutations found from the SNPs NCBI dataset of C20orf85, these included below were mentioned as described in the "significance" column.

| SNP | Position (aa) | Base Change | Amino Acid Change | Mutation Type | Significance | Clinical Significance |
| - | - | - | - | - | - | - |
| rs1207088890 | 7 | A-->G | Ser-->Gly | Missense | Highly conserved with phosphorylation site and O-beta-GlcNAc site | None known |
| rs907822000 | 16 | C-->T | Leu-->Phe | Missense | Highly conserved | None known |
| rs780117816 | 24 | A-->T | Lys--> N/A | Nonsense | Sumoylation site | None known |
| rs200564315 | 100 | G-->A | Gly-->Ser | Missense | Highly conserved | None known |
| rs754178666 | 137 | A-->G | His-->Arg | Missense | Important to localization | None known |
