Fetal protein
Encyclopedia
Fetal proteins are simply protein
s present at highest levels at the fetus
stage. Often related proteins assume similar roles after birth or in the embryo
, in which case the fetal varieties are called fetal isoforms. Sometimes the gene
s coding fetal isoforms occur adjacent to their adult homologues
in the genome
, and in those cases a locus control region
often coordinates the transition from fetal to adult forms. In other cases fetal isoforms can be produced by alternate splicing using fetal exon
s to produce proteins that differ in only a portion of their amino acid
sequence. In some situations the reexpression or continuing expression of fetal forms can reveal the presence of a disease condition or serve as a treatment for diseases such as sickle cell anemia. Some well known examples include:
Protein
Proteins are biochemical compounds consisting of one or more polypeptides typically folded into a globular or fibrous form, facilitating a biological function. A polypeptide is a single linear polymer chain of amino acids bonded together by peptide bonds between the carboxyl and amino groups of...
s present at highest levels at the fetus
Fetus
A fetus is a developing mammal or other viviparous vertebrate after the embryonic stage and before birth.In humans, the fetal stage of prenatal development starts at the beginning of the 11th week in gestational age, which is the 9th week after fertilization.-Etymology and spelling variations:The...
stage. Often related proteins assume similar roles after birth or in the embryo
Embryo
An embryo is a multicellular diploid eukaryote in its earliest stage of development, from the time of first cell division until birth, hatching, or germination...
, in which case the fetal varieties are called fetal isoforms. Sometimes the gene
Gene
A gene is a molecular unit of heredity of a living organism. It is a name given to some stretches of DNA and RNA that code for a type of protein or for an RNA chain that has a function in the organism. Living beings depend on genes, as they specify all proteins and functional RNA chains...
s coding fetal isoforms occur adjacent to their adult homologues
Homology (biology)
Homology forms the basis of organization for comparative biology. In 1843, Richard Owen defined homology as "the same organ in different animals under every variety of form and function". Organs as different as a bat's wing, a seal's flipper, a cat's paw and a human hand have a common underlying...
in the genome
Genome
In modern molecular biology and genetics, the genome is the entirety of an organism's hereditary information. It is encoded either in DNA or, for many types of virus, in RNA. The genome includes both the genes and the non-coding sequences of the DNA/RNA....
, and in those cases a locus control region
Locus Control Region
Locus control regions are defined by their ability to enhance the expression of linked genes to physiological levels in a tissue-specific and copy number-dependent manner at ectopic chromatin sites...
often coordinates the transition from fetal to adult forms. In other cases fetal isoforms can be produced by alternate splicing using fetal exon
Exon
An exon is a nucleic acid sequence that is represented in the mature form of an RNA molecule either after portions of a precursor RNA have been removed by cis-splicing or when two or more precursor RNA molecules have been ligated by trans-splicing. The mature RNA molecule can be a messenger RNA...
s to produce proteins that differ in only a portion of their amino acid
Amino acid
Amino acids are molecules containing an amine group, a carboxylic acid group and a side-chain that varies between different amino acids. The key elements of an amino acid are carbon, hydrogen, oxygen, and nitrogen...
sequence. In some situations the reexpression or continuing expression of fetal forms can reveal the presence of a disease condition or serve as a treatment for diseases such as sickle cell anemia. Some well known examples include:
- Alpha-fetoproteinAlpha-fetoproteinAlpha-fetoprotein is a protein that in humans is encoded by the AFP gene....
, the predominant serum protein of the fetus which gives way to albuminAlbuminAlbumin refers generally to any protein that is water soluble, which is moderately soluble in concentrated salt solutions, and experiences heat denaturation. They are commonly found in blood plasma, and are unique to other blood proteins in that they are not glycosylated...
in the adult. - Fetal hemoglobinFetal hemoglobinFetal hemoglobin, or foetal haemoglobin, is the main oxygen transport protein in the fetus during the last seven months of development in the uterus and in the newborn until roughly 6 months old...
, the fetal version of hemoglobinHemoglobinHemoglobin is the iron-containing oxygen-transport metalloprotein in the red blood cells of all vertebrates, with the exception of the fish family Channichthyidae, as well as the tissues of some invertebrates...
. - Fetal Troponin TTroponin TTroponin T is a part of the troponin complex. It binds to tropomyosin, interlocking them to form a troponin-tropomyosin complex.The tissue specific subtypes are:* Slow skeletal troponin T1, TNNT1 * Cardiac troponin T2, TNNT2...
and Troponin ITroponin ITroponin I is a part of the troponin complex. It binds to actin in thin myofilaments to hold the actin-tropomyosin complex in place. Because of it myosin cannot bind actin in relaxed muscle...
isoforms.