# TMEM252

TMEM252 or transmembrane protein 252 is a protein that, in humans, is encoded by the TMEM252 gene.

## Gene

Transmembrane protein 252 (TMEM252), otherwise known as chromosome 9 open reading frame 71 (C9orf71), is a gene that encodes for the TMEM252 protein. This gene is found on chromosome 9, and it spans over 3000 base pairs. Additionally, this gene is made up of 2 exons, with exon 1 stopping at nucleotide 346 and exon 2 beginning at nucleotide 347. The mRNA transcript is 1261 nucleotides in length.

## Protein

The TMEM252 protein is 170 amino acids in length. There are 2 transmembrane domains and one disordered region within this protein. The predicted molecular weight of the unmodified precursor protein is 18.7 kDa. The theoretical isoelectric point of this precursor protein is 4.88. There are no known isoforms of TMEM252.

## Expression

This gene is expressed mainly in the kidney and small intestine of humans; however, there are 10 other organs in which TMEM252 is expressed, just at a lower rate. When RNA sequencing was done among 20 tissues, it was found that the kidney and prostate had the highest expression for TMEM252. In the fetal development of a baby, the highest expression of TMEM252 is in the 10-week heart and kidney, and the 20-week stomach and intestine. There is consistency between these expressions, as it can be concluded that the most prominent tissue expression of TMEM252 is in the kidney.

## Homology and evolutionary history

TMEM252 can be found in mammals, reptiles, birds, amphibians, and fish. TMEM252 first appeared in fish about 431 million years ago. This was the first occurrence of this gene. There are no orthologs for this gene in jawless vertebrates, invertebrates, plants and fungi. Additionally, there are no paralogs of TMEM252.
TMEM252 first appeared in fish about 431 million years ago. TMEM252 is evolving relatively quickly compared to fibrinogen alpha.
Table of TMEM252 Orthologs :
| Genus and Species | Common Name | Order | Date of Divergence (MYA) | Accession Number | Length (AA) | % Identity w Humans | % Similarity w Humans |
| Homo sapiens | Human | primate | 0 | NP_694969.1 | 170 | 100 | 100% |
| Cebus imitator | Panamanian White-Faced Capuchin | primate | 43 | XP_017398911.1 | 170 | 86.5 | 90.60% |
| Orcinus orca | Orca | cetacea | 94 | XP_004276471.1 | 171 | 71.9 | 82.50% |
| Choloepus didactylus | Linnaeus's Two-Toed Sloth | pilosa | 99 | XP_037707165.1 | 170 | 72.4 | 82.90% |
| Crotalus tigris | Tiger Rattlesnake | squamata | 319 | XP_039218251.1 | 168 | 38.9 | 54.10% |
| Gallus gallus | Chicken | galliformes | 319 | XP_046791631.1 | 177 | 35 | 52.50% |
| Caretta caretta | Loggerhead Sea Turtle | testudines | 319 | XP_048705310.1 | 193 | 34.5 | 49.50% |
| Crocodylus porosus | Saltwater Crocodile | crocodilia | 319 | XP_019410953.1 | 196 | 33.8 | 49.00% |
| Nipponia nippon | Crested Ibis | pelecaniformes | 319 | XP_009460509.1 | 167 | 33.5 | 50.80% |
| Apteryx rowi | Okarito Kiwi | apterygiformes | 319 | XP_025915801.1 | 188 | 33.2 | 48.70% |
| Brachypteracias leptosomus | Short-legged Ground-roller | coraciiformes | 319 | NXS61352.1 | 175 | 32.1 | 44.90% |
| Onychostruthus taczanowskii | White-rumped Snow Finch | passeridae | 319 | XP_041282844.1 | 194 | 29.2 | 44.80% |
| Microcaecilia unicolor | Microcaecilia Unicolor | caecilians | 353 | XP_030048238.1 | 184 | 37.6 | 50.80% |
| Bufo gargarizans | Asiatic Toad | anura | 353 | XP_044143156.1 | 172 | 36.8 | 53.80% |
| Xenopus tropicalis | Western Clawed Frog | anura | 353 | XP_004910840.1 | 183 | 35.8 | 55.10% |
| Chanos chanos | Milkfish | gonorynchiformes | 431 | XP_030620693.1 | 168 | 32.8 | 47.00% |
| Pangasianodon hypophthalmus | Iridescent Shark | shark | 431 | XP_026784303.1 | 178 | 29.6 | 44.70% |
| Oncorhynchus mykiss | Rainbow Trout | salmoniformes | 431 | XP_021477694.1 | 186 | 29.4 | 43.80% |
| Amphiprion ocellaris | Ocellaris Clownfish | perciformes | 431 | XP_023154880.1 | 174 | 28.6 | 42.30% |
| Electrophorus electricus | Electric Eel | gymnotiformes | 431 | XP_026870189.2 | 209 | 25.7 | 40.50% |
| Larimichthys crocea | Yellow Croaker | acanthuriformes | 431 | TMS03948.1 | 171 | 23.2 | 37.40% |

### Clinical Relevance

TMEM252 was found to be one of six novel genes associated with the prognosis of triple-negative breast cancer. Patients who had one or more of the six novel genes had significantly lower survival rates than those without. There are no relevant studies for TMEM252 and its relation to tumors.