Are Proteins Inherited? 3 Facts You Should Know

Genetics is the process of the transfer of traits from one generation to another. These traits are transferred from one generation to another via genetic materials.

These traits that we refer to are actually proteins, which are expressed via their respective genes.

According to recent studies scientists have confirmed that proteins can also function as genetic material just like DNA and RNA.

What are traits?

Traits are features or properties of a living organism that are affected by the environment and/or expressed by genes.

Traits can be visible t the naked eye or affect internal factors. For example features like height, skin colour, hair colour, and eye colour are traits visible to the naked eye. Whereas traits like genetic disorders and blood groups are genetic homogeneity/heterogeneity are internal factors.

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Alleles showing blood group traits
Image: Wikipedia

These traits are carried on from the previous generation as genes that express specific proteins. These proteins can be factors, hormones or enzymes that bring about the characteristics in an individual.

Why are proteins inherited?

Proteins are inherited from one generation to the next in the form of traits that are important to establishing the physical and genetic characteristics of an individual.

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A pedigree table how genotypic trait of an autosomal recessive disorders is passed from one generation to another
Image: Wikipedia

Traits are nothing but proteins expressed by inherited genes. These proteins can be factors, enzymes and hormones that determine the physical and genetic composition of an individual organism and partially that of the next generation as well.

The height of a person is a genetic factor that decided how much of the growth hormone will be released. This growth hormone is basically a protein hence it requires to be inherited from its predecessor.

When are proteins inherited?

Proteins are inherited as genes from the parents to the next generation. The DNA pairs in the zygote have one strand from the mother and one from the father containing a mixture of genes.

These genes are carried by the DNA  alleles. Each allele gives rise to a specific trait due to the presence of its specific genes. Hence in trait form proteins are inherited during the process of meiosis for gamete formation.

However, proteins like prions have the ability to be inherited as they are. Hence scientists claim that these prion proteins are also capable of functioning as genetic material. Prions in both yeast and mammalian cells transfer phenotypes through protein-protein interactions, in which an improperly shaped prion protein causes its normal counterpart to take on an aberrant form.

How are proteins inherited?

Typically proteins are inherited in the form of three amino acid codons in the DNA. The DNA is transcribed and translated to get the specific protein.

As genes:

Traits are properties or qualities that are passed down to someone — or inherited — from their parents. Genes contain the information that defines your traits. Each human cell has between 25,000 and 35,000 genes.

There are hundreds — often thousands — of genes on a single chromosome, which come in matching pairs and are all made up of DNA.

Transcription and translation:

Genes that are inherited express their respective proteins via transcription and translation.

Transcription:

The DNA sequence between the start and finish of a gene is read by structures in the cell (the order of A, C, G and T bases within the gene). A biochemical message (an mRNA molecule) is created, which repeats the gene’s sequence. In most ways, mRNA resembles a single-stranded strand of DNA replacing T with another base U.

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DNA transcripted to form mRNA
Image: Wikipedia

Translation:

When a ribosome receives an mRNA molecule, it begins to construct a sequence of amino acid residues (a protein) that precisely follows the mRNA’s instructions. The mRNA sequence is read by the ribosome as a succession of three-base fragments called codons. Each codon instructs the protein-making machinery to add the next amino acid.

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RNA translated to protein
Image: Wikipedia

Conclusion:

So the answer to the question “are proteins inherited?” would be a yes, except it is not inherited the way we perceive it. Proteins are passed down as traits from one generation to the next in the form of genes in the DNA sequence. However, some specific proteins like prions can inherit themselves in the protein form from one generation to the next.

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