FAM71F2 or Family with Sequence Similarity 71 member F2 is a

protein Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residue (biochemistry), residues. Proteins perform a vast array of functions within organisms, including Enzyme catalysis, catalysing metab ...

that in humans is encoded by the ''Family with Sequence Similarity 71 member F2 gene''. This gene is highly active in the reproductive tissues, specifically the

testis A testicle or testis ( testes) is the gonad in all male bilaterians, including humans, and is Homology (biology), homologous to the ovary in females. Its primary functions are the production of sperm and the secretion of Androgen, androgens, p ...

, and may serve as a potential

biomarker In biomedical contexts, a biomarker, or biological marker, is a measurable indicator of some biological state or condition. Biomarkers are often measured and evaluated using blood, urine, or soft tissues to examine normal biological processes, ...

for determining metastatic

testicular cancer Testicular cancer is cancer that develops in the testicles, a part of the male reproductive system. Symptoms may include a lump in the testicle or swelling or pain in the scrotum. Treatment may result in infertility. Risk factors include an c ...

Gene

Location

FAM71F2 gene is located on

chromosome 7 Chromosome 7 is one of the 23 pairs of chromosomes in humans, who normally have two copies of this chromosome. Chromosome 7 spans about 160 million base pairs (the building material of DNA) and represents between 5 and 5.5 percent of the total DN ...

in humans (7q32.1), starting at 128,671,636 and ending at 128,702,262 on the positive strand. The gene

paralog Sequence homology is the biological homology between DNA, RNA, or protein sequences, defined in terms of shared ancestry in the evolutionary history of life. Two segments of DNA can have shared ancestry because of three phenomena: either a sp ...

FAM71F1 and the gene LINC01000 directly neighbor FAM71F2 on chromosome 7.

Size of gene

The gene spans 30,627

base pair A base pair (bp) is a fundamental unit of double-stranded nucleic acids consisting of two nucleobases bound to each other by hydrogen bonds. They form the building blocks of the DNA double helix and contribute to the folded structure of both DNA ...

s and codes for 12

exon An exon is any part of a gene that will form a part of the final mature RNA produced by that gene after introns have been removed by RNA splicing. The term ''exon'' refers to both the DNA sequence within a gene and to the corresponding sequence ...

Common aliases

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

mRNA

FAM71F2 has 14

transcript variant Alternative splicing, alternative RNA splicing, or differential splicing, is an alternative RNA splicing, splicing process during gene expression that allows a single gene to produce different splice variants. For example, some exons of a gene ma ...

s. ''

Isoform A protein isoform, or "protein variant", is a member of a set of highly similar proteins that originate from a single gene and are the result of genetic differences. While many perform the same or similar biological roles, some isoforms have uniqu ...

'' ''a'' is the longest of the

mRNA In molecular biology, messenger ribonucleic acid (mRNA) is a single-stranded molecule of RNA that corresponds to the genetic sequence of a gene, and is read by a ribosome in the process of Protein biosynthesis, synthesizing a protein. mRNA is ...

transcripts and spans 5,775 base pairs that translates into a 309

amino acid Amino acids are organic compounds that contain both amino and carboxylic acid functional groups. Although over 500 amino acids exist in nature, by far the most important are the 22 α-amino acids incorporated into proteins. Only these 22 a ...

s sequence. It codes for 5 exons. Other alternative splice isoforms are labelled in the diagram in Figure 2. Annotated transcripts

At the first splice site, ''Isoform b'', found in most

reptile Reptiles, as commonly defined, are a group of tetrapods with an ectothermic metabolism and Amniotic egg, amniotic development. Living traditional reptiles comprise four Order (biology), orders: Testudines, Crocodilia, Squamata, and Rhynchocepha ...

s having FAM71F2 protein, deletes the following nine amino acids and picks up at the

valine Valine (symbol Val or V) is an α-amino acid that is used in the biosynthesis of proteins. It contains an α- amino group (which is in the protonated −NH3+ form under biological conditions), an α- carboxylic acid group (which is in the deproton ...

amino acid at location 61 in humans. ''Isoform c'' uses an alternative downstream start site to ''Isoform a'' and adds another exon between the first and second exons of ''Isoform a.''

General properties

The

molecular weight A molecule is a group of two or more atoms that are held together by Force, attractive forces known as chemical bonds; depending on context, the term may or may not include ions that satisfy this criterion. In quantum physics, organic chemi ...

of FAM71F2 is 34.5 kilodaltons. The isoelectric point is 6.15.

Domains and motifs

FAM71F2 protein contains only one domain, named

domain of unknown function A domain of unknown function (DUF) is a protein domain that has no characterised function. These families have been collected together in the Pfam database using the prefix DUF followed by a number, with examples being DUF2992 and DUF1220. As of 201 ...

, DUF3699. This domain is located from amino acids 114-185 on the human FAM71F2 protein. This domain family is found only in

eukaryotes The eukaryotes ( ) constitute the domain of Eukaryota or Eukarya, organisms whose cells have a membrane-bound nucleus. All animals, plants, fungi, seaweeds, and many unicellular organisms are eukaryotes. They constitute a major group of ...

and approximately 71 amino acids in length.NCBI (National Center for Biotechnology Information) entry on FAM71F2
/nowiki> There is also a potential

R-2 mitochondrial pre-sequence cleavage site R- may represent: *a type of chirality, in chemical notation *an ''R'' prefix used for various constants *the set of negative real numbers *negative reinforcement In behavioral psychology, reinforcement refers to consequences that increase th ...

that would signal the protein to the

mitochondria A mitochondrion () is an organelle found in the cells of most eukaryotes, such as animals, plants and fungi. Mitochondria have a double membrane structure and use aerobic respiration to generate adenosine triphosphate (ATP), which is us ...

. These sites are labelled in Figure 4 below.

Secondary structure

The

secondary structure Protein secondary structure is the local spatial conformation of the polypeptide backbone excluding the side chains. The two most common Protein structure#Secondary structure, secondary structural elements are alpha helix, alpha helices and beta ...

of FAM71F2 contains

alpha helices An alpha helix (or α-helix) is a sequence of amino acids in a protein that are twisted into a coil (a helix). The alpha helix is the most common structural arrangement in the secondary structure of proteins. It is also the most extreme type of l ...

and

beta sheet The beta sheet (β-sheet, also β-pleated sheet) is a common motif of the regular protein secondary structure. Beta sheets consist of beta strands (β-strands) connected laterally by at least two or three backbone hydrogen bonds, forming a gene ...

s. 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.

Post-translational modifications

FAM71F2 has seven highly conserved

phosphorylated site Protein phosphorylation is a reversible post-translational modification of proteins in which an amino acid residue is phosphorylated by a protein kinase by the addition of a covalently bound phosphate group. Phosphorylation alters the structural ...

s. There is one

acetylation site : In chemistry, acetylation is an organic esterification reaction with acetic acid. It introduces an acetyl group into a chemical compound. Such compounds are termed ''acetate esters'' or simply ''acetates''. Deacetylation is the opposite reacti ...

and one

N-glycosylation ''N''-linked glycosylation is the attachment of an oligosaccharide, a carbohydrate consisting of several sugar molecules, sometimes also referred to as glycan, to a nitrogen atom (the amide nitrogen of an asparagine (Asn) residue of a protein), i ...

site, playing a role in stabilizing the protein. Schematic Diagram

Sub-cellular localization

FAM71F2 protein stays in the

cytoplasm The cytoplasm describes all the material within a eukaryotic or prokaryotic cell, enclosed by the cell membrane, including the organelles and excluding the nucleus in eukaryotic cells. The material inside the nucleus of a eukaryotic cell a ...

of cells, but may have localization in the nucleus and mitochondria.

Expression

Tissue expression pattern

FAM71F2 is highly expressed in reproductive structures, such as the testis,

epididymis The epididymis (; : epididymides or ) is an elongated tubular genital organ attached to the posterior side of each one of the two male reproductive glands, the testicles. It is a single, narrow, tightly coiled tube in adult humans, in length; ...

uterus The uterus (from Latin ''uterus'', : uteri or uteruses) or womb () is the hollow organ, organ in the reproductive system of most female mammals, including humans, that accommodates the embryonic development, embryonic and prenatal development, f ...

and

ovaries The ovary () is a gonad in the female reproductive system that produces ova; when released, an ovum travels through the fallopian tube/oviduct into the uterus. There is an ovary on the left and the right side of the body. The ovaries are endocr ...

. There is some expression in the brain and

connective tissue Connective tissue is one of the four primary types of animal tissue, a group of cells that are similar in structure, along with epithelial tissue, muscle tissue, and nervous tissue. It develops mostly from the mesenchyme, derived from the mesod ...

as well. As development stages progress, the number of gene transcripts increases and are at highest expression levels in adults. In the mouse, during

spermatogenesis Spermatogenesis is the process by which haploid spermatozoa develop from germ cells in the seminiferous tubules of the testicle. This process starts with the Mitosis, mitotic division of the stem cells located close to the basement membrane of ...

and development of the testis, gene transcript levels of FAM71F2 increase dramatically.

Cellular expression

FAM71F2 protein expression has been detected in the cytoplasm of

Leydig cells Leydig cells, also known as interstitial cells of the testes and interstitial cells of Leydig, are found adjacent to the seminiferous tubules in the testicle and produce testosterone in the presence of luteinizing hormone (LH). They are polyhedral ...

and in epididymis cells of the male testis and is also detected in the cytoplasm in

ovarian follicle An ovarian follicle is a roughly spheroid cellular aggregation set found in the ovaries. It secretes hormones that influence stages of the menstrual cycle. In humans, women have approximately 200,000 to 300,000 follicles at the time of puberty, ea ...

Expression level

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

Clinical significance

FAM71F2 is repressed in males with non-obstructive azoospermia and

teratozoospermia Teratospermia or teratozoospermia is a condition characterized by the presence of sperm with abnormal morphology that affects fertility in males. Causes The causes of teratozoospermia are unknown in most cases. However, Hodgkin's disease, coeliac ...

, or abnormalities in

sperm Sperm (: sperm or sperms) is the male reproductive Cell (biology), cell, or gamete, in anisogamous forms of sexual reproduction (forms in which there is a larger, female reproductive cell and a smaller, male one). Animals produce motile sperm ...

morphology and quantity. These diseases lead to fertility issues. In addition, FAM71F2 gene expression is up-regulated with

Dopamine receptor D1 Dopamine receptor D1, also known as DRD1. It is one of the two types of D1-like receptor family receptors D1 and D5. It is a protein that in humans is encoded by the DRD1 gene. Tissue distribution D1 receptors are the most abundant kind of d ...

expression in

patients, and may be an important biomarker for metastatic forms of this cancer.

Homology

FAM71F2 has 91

ortholog Sequence homology is the biological homology between DNA, RNA, or protein sequences, defined in terms of shared ancestry in the evolutionary history of life. Two segments of DNA can have shared ancestry because of three phenomena: either a speci ...

s in other animal species. Its evolutionary history goes as far back as the reptiles, and its most distant relative is the homolog in the

west Indian Ocean coelacanth The West Indian Ocean coelacanth (''Latimeria chalumnae'') (sometimes known as gombessa, African coelacanth, or simply coelacanth) is a crossopterygian, one of two extant species of coelacanth, a rare order of vertebrates more closely related to ...

. The time of divergence between eight orthologs from the human FAM71F2 is shown in Figure 5. It is not found in birds or in ''

Gallus gallus The red junglefowl (''Gallus gallus''), also known as the Indian red junglefowl (and formerly the bankiva or bankiva-fowl), is a species of Tropics, tropical, predominantly Terrestrial animal, terrestrial bird in the fowl and pheasant family, P ...

'' (chicken). FAM71F2 has six

s in humans: FAM71A, FAM71B, FAM71C,

FAM71D FAM71D, also known as chromosome 14 open reading frame 54 (C14orf54), is a protein that in humans is encoded by the FAM71D gene on Chromosome 7 (human), Chromosome 14. Homology (biology)#Orthology, Orthologs of FAM71D reach as far back in evolutio ...

FAM71E1 FAM71E1, also known as Family With Sequence Similarity 71 Member E1, is a protein that in humans is encoded by the FAM71E1 gene. It is thought to be ubiquitously expressed at low levels throughout the body, and it is conserved in vertebrates, parti ...

, and FAM71F1. Date of Divergence for FAM71F2

References

{{Reflist Genes on human chromosome 7