FAM71F2

Figure 1. Location of the gene FAM71F2, marked with a blue rectangle, on Chromosome 7. Neighboring genes in the area are labelled as well.

FAM71F2 gene is located on chromosome 7 in humans (7q32.1),[5][6] starting at 128,671,636 and ending at 128,702,262 on the positive strand.[6] The gene paralog FAM71F1 and the gene LINC01000 directly neighbor FAM71F2 on chromosome 7.

The gene spans 30,627 base pairs[6] and codes for 12 exons.[5]

FAM71F2 is also referred to as family with sequence similarity 137 member B, FAM137B.[6]

The molecular weight of FAM71F2 is 34.5 kilo Daltons.[7] The isoelectric point is 6.15.[8]

FAM71F2 protein contains only one domain, named domain of unknown function, DUF3699.[5][6] This domain is located from amino acids 114-185 on the human FAM71F2 protein.[5] This domain family is found only in eukaryotes and approximately 71 amino acids in length.[5] There is also a potential R-2 mitochondrial pre-sequence cleavage site[9] that would signal the protein to the mitochondria. These sites are labelled in Figure 4 below.

The secondary structure of FAM71F2 contains alpha helices and beta sheets.[10][11] These structures are identified in the generated image of the FAM71F2 protein in Figure 3. Highly conserved amino acid residues, such as the Val61-Thr62-Lys63 sequence where the reptiles and isoform b pick up in the second exon, are labelled on this figure as well.

Figure 3. Diagram of the FAM71F2 protein[12] with secondary structures and highly conserved amino acid residues. Alpha helices are labelled in orange, beta sheets in cyan, the N-terminus is magenta, and the C-terminus is green.

FAM71F2 has seven highly conserved phosphorylated sites. There is one acetylation site[13] and one N-glycosylation site,[14] playing a role in stabilizing the protein.

Figure 4. Schematic diagram of FAM71F2 protein.[15] The DUF3699 domain is labelled as the large, grey hexagonal shape. A potential R-2 mitochondrial targeting sequence shown at 5' end is labelled with a red rectangle. Conserved phosphorylation sites are labelled with the red stop sign images and a 5' acetylation site on the second amino acid is labelled with a grey stop sign image. A N-terminus glycosylation site on Met98 is shown as a thin, green rectangle and two cysteine bonds are labelled with the green brackets.

FAM71F2 protein stays in the cytoplasm of cells,[9] but may have localization in the nucleus and mitochondria.[9]

FAM71F2 is highly expressed in reproductive structures, such as the testis, epididymis, uterus and ovaries.[5][16] There is some expression in the brain and connective tissue as well.[17] As development stages progress, the number of gene transcripts increases and are at highest expression levels in adults.[17] In the mouse, during spermatogenesis and development of the testis, gene transcript levels of FAM71F2 increase dramatically.[18]

FAM71F2 protein expression has been detected in the cytoplasm of Leydig cells and in epididymis cells of the male testis and is also detected in the cytoplasm in ovarian follicles.[16]

Figure 4. Immunohistological staining of FAM71F2 in the human testis.[16]

FAM71F2 is moderately expressed in comparison to other proteins in the human, with an average protein expression level of 8.47 part per million.[19]