FAM40A

FAM40A has an isoelectric point of 5.92 and a molecular weight of 95,575 daltons.[8] It is predicted to have three transmembrane domains, making it a transmembrane protein.[9] 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.[10][11]

Prediction of the orientation of the transmembrane domains of FAM40A

The secondary structure of FAM40A is predicted to contain twenty-six alpha helices and two beta sheets.[12] 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.[13] Two miRNAs are predicted to bind to two of the stem-loop structures present in the 3' UTR region.[14]

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.[15][16]

The following table represents a small selection of orthologs found using searches in BLAST[17] and BLAT.[18] This is by no means a comprehensive list, however it does show the vast diversity of species where FAM40A orthologs are found.

FAM40A is expressed in high levels during the blastocyst, eight-cell stage, and fetal stages of development.[19] FAM40A has also been shown to be expressed in high levels in the mammary glands, brain, thymus, mouth and the testes.[20] It has also been shown to be expressed in high levels in mammary gland tumors, leukemia cells, and germ cell tumors.[20]

Predicted FAM40A expression in different tissues of the body

FAM40A is predicted to have a promoter region 789 base pairs upstream of the start of transcription.[21] The SOX transcription factors are predicted to bind to the promoter region of the FAM40A gene, possibly indicating a role in sex determination.[21]

FAM40A has been shown to interact with RP6-213H19.1,[22] STRN,[22] PDCD10,[22] TRAF3IP3,[22] STRN3,[22] PPP2R1A,[22] MOBKL3,[22] CTTNBP2NL,[22] STK24[22][23] and PPP2CA.[22]