# FAM40A

Protein FAM40A is a protein that is located on chromosome 1 in humans and is encoded by the FAM40A gene.

## Characteristics and secondary structure

FAM40A has an isoelectric point of 5.92 and a molecular weight of 95,575 daltons. It is predicted to have three transmembrane domains, making it a transmembrane protein. FAM40A does not contain a signal peptide and is also predicted to bind to DNA, possibly making it a membrane protein in the nuclear membrane.
The secondary structure of FAM40A is predicted to contain twenty-six alpha helices and two beta sheets. The 5' untranslated region of FAM40A is predicted to contain one stem-loop and the 3' untranslated region is predicted to contain eight stem-loop structures. Two miRNAs are predicted to bind to two of the stem-loop structures present in the 3' UTR region.

## Homology

FAM40A has no paralogs. However, it does have orthologs stretching all the way back to yeast. It has been suggested that FAM40A is a homolog to the yeast gene FAR11, which is involved in the recovery from cell cycle arrest.
The following table represents a small selection of orthologs found using searches in BLAST and BLAT. This is by no means a comprehensive list, however it does show the vast diversity of species where FAM40A orthologs are found.
| Scientific Name | Common Name | Accession number (from NCBI) | Sequence Length | Percent Identity | Percent Similarity |
| Homo sapiens | Human | NP_149079 | 837 | - | - |
| Pongo abelii | Sumatran orangutan | XP_002810520 | 837 | 99.6% | 100% |
| Sus scrofa | Pig | XP_003125904 | 837 | 98.8% | 100% |
| Equus caballus | Horse | XP_001493762 | 837 | 98.8% | 100% |
| Mus musculus | Mouse | NP_705791 | 837 | 98% | 100% |
| Rattus norvegicus | Rat | XP_001068288 | 837 | 97.8% | 100% |
| Monodelphis domestica | Gray short-tailed opossum | XP_001372588 | 843 | 95.4% | 100% |
| Danio rerio | Zebra fish | XP_001918929 | 813 | 83.4% | 98% |
| Canis lupus familiaris | Dog | From BLAT | 812 | 96.1% | 100% |
| Ailuropoda melanoleuca | Panda | From BLAT | 823 | $96.2 | 100% |
| Oryzias latipes | Medaka | From BLAT | 751 | 78.4% | 96% |
| Xenopus (Silurana) tropicalis | Western clawed frog | NP_001027483 | 819 | 86.4% | 96% |
| Aedes aegypti | Yellow-fever mosquito | XP_001658692 | 829 | 51.2% | 97% |
| Tribolium castaneum | Red flour beetle | XP_001815164 | 817 | 57.4% | 97% |
| Hydra magnipapillata | Hydra hydrozoan | XP_002164866 | 830 | 44% | 97% |
| Ciona intestinalis | Sea squirt | XP_002130558 | 867 | 46.4% | 97% |
| Pediculus humanus corporis | Human lice | XP_002425964 | 808 | 52.7% | 97% |
| Nasonia vitripennis | Jewel wasp | XP_001603859 | 802 | 52.7% | 97% |
| Drosophila erecta | Fruit fly | XP_001971743 | 882 | 45.2% | 97% |
| Saccharomyces cerevisiae | Bakers yeast | NP_014272 | 953 | 18.9% | 97% |

## Expression

FAM40A is expressed in high levels during the blastocyst, eight-cell stage, and fetal stages of development. FAM40A has also been shown to be expressed in high levels in the mammary glands, brain, thymus, mouth and the testes. It has also been shown to be expressed in high levels in mammary gland tumors, leukemia cells, and germ cell tumors.

## Transcription Regulation

FAM40A is predicted to have a promoter region 789 base pairs upstream of the start of transcription. The SOX transcription factors are predicted to bind to the promoter region of the FAM40A gene, possibly indicating a role in sex determination.

## Interactions

FAM40A has been shown to interact with RP6-213H19.1, STRN, PDCD10, TRAF3IP3, STRN3, PPP2R1A, MOBKL3, CTTNBP2NL, STK24 and PPP2CA.