When Was Keratin Discovered? [Significant Developments]

If you’re wondering and meaning to ask, “when was keratin discovered” get ready to question answered.

My years of experience in the beauty industry always validate the idea that keratin is the most important protein in human hair, which is why it’s okay to know when this magic was discovered.

But here, I also simplify the keratin synthesis process, keratin’s role in epidermal development, and how it matters for hair growth.

So first things first…

CHECK: Why Keratin is So Expensive?

When was Keratin Discovered?

The structural protein, keratin, was discovered in 1991 (1).

Although intermediate filaments had been characterized before then, this discovery in 1991 helped to establish the role of human keratins intermediate filaments in epidermal cells of the human skin epidermis and several other epithelial cells, e.g., in the intestinal epithelium, foveolar epithelium, etc.

The expression of keratin in epithelial cells was linked to certain mechanical properties, as cell fragility was discovered in epithelial cells suspected to have hereditary keratin diseases.

Studies conducted using mouse genomes in transgenic mice models revealed the role of epidermal keratin intermediate filament protein (including their mechanical properties) and their expression patterns.

The skeletal muscle cells of transgenic mice were used particularly for these studies since skeletal muscles are a good model for studying mechanical activities.

The keratin synthesis process and the patterns of expression of this cytoskeletal protein have also been elucidated, and this has significantly increased the application of keratins in epidermal development.

From the evidence provided by cell biology findings, we know that this cytoskeletal protein is produced through a series of steps beginning with the gene expression before ultimately ending with the protein expression.

This is necessary for the protein’s amino acid sequence to be adequately maintained.

Across the different epidermal layers (i.e., the basal layers and the outer layer), the epithelial differentiation of the keratin-producing cells, keratinocytes, is continuous to sustain epidermal development.

For instance, in human hair, keratin production is by hair follicle stem cells which undergo epithelial differentiation to give rise to keratinocytes in the basal layer of the interfollicular epidermis.

Significant Developments Before and After the Discovery of Keratin

Before and after the discovery of keratin, several studies have made significant developments. Most of these studies aim to better understand keratin’s characteristics and tissue-specific expression patterns.

To begin with, about twenty years ago, when the protein names of all the known human keratins were published in research by Moll Et Al., only 19 cytoskeletal protein variants in the phylogenetic trees of the keratin gene family were known. Now, there are 54 keratin genes known to be involved with keratin production.

The acidic protein category with amino acids carrying an acidic charge had 18 members, while there was just one basic keratin known then.

From recent immunohistochemical studies, antibodies to keratin have been used in human skin epidermis research (2).

Epithelial cytokeratins/keratin intermediate filaments have been significantly found to be useful as markers in tumor pathology, according to research (3).

Currently, about 20 cytokeratins have been discovered, including cytokeratin 18 and cytokeratin 20. In understanding epithelial tumors, including epithelial tumors of the luminal cells in mammary tissue, transitional cell carcinomas, basal cell carcinomas, and palmoplantar keratoderma, these epithelial cytokeratins have played a role in serving as markers in tumor pathology.

You can read more about the discoveries that have been made on the application of keratins and cytokeratins in understanding tumor pathology by checking out research papers that are available online.

Some of the research study authors to check to include Moll et al. – The human keratin: Biology and Pathology, J. Schweizer Et Al. – New consensus nomenclature for mammalian keratins, L. Langbein Et Al. – The catalog of human hair keratins, Elaine Fuchs E. – The expression of keratin genes in the epidermis and cultured epidermal cells, M.A. Rogers Et Al. – Low fossilization potential of keratin protein revealed by experimental taphonomy, Coulombe Et Al. – A function for keratins and a common thread among different types of epidermolysis bullosa simplex diseases, Leube RE – Structural and regulatory functions of keratins, Toivola Et Al. – Keratins in health and diseases, Galarneau Et Al. – Keratins modulate hepatic cell adhesion, size, and G1/S transition, Omary MB – Keratins turn over by ubiquitination in a phosphorylation-modulated fashion, Leigh IM – Keratin 19: predicted amino acid sequence and broad tissue distribution, Eady RA – Human keratin diseases, Degenstein L – Deciphering keratin functions. You can also consult the journal of cell biology for more findings.

Some of the significant findings on keratin synthesis have been applied in formulating keratin solutions which are now used in keratin hair treatments.

These keratin hair treatments prevent hair loss, especially in human hair with low keratin levels. Now such defects in human hair, such as hair loss, hair breakage, and frizzy hair, have been significantly solved through these significant developments.

You can watch this video to understand how keratin hair treatment works:


Who discovered keratin protein?

Israel Hanuklogu and Elaine Fuchs were the people who determined the sequences of the first keratins.

Where is keratin first produced?

Keratin is first produced in simple epithelial embryos.

What is human keratin made of?

Human keratin is composed of a sequence of several amino acids, with cystine being the most important.


Now that you’ve gotten answers to your question, “when was Keratin discovered” I’m pretty sure you have a deeper into the development and impact of keratin on the hair.

If there’s something we can agree on, it is simply that the application of keratins has contributed tremendously to several developments in understanding hereditary keratin diseases and the cell biology of the genetic diseases in several epithelial tissues.

A lady applying keratin on her hair under title When was Keratin Discovered?


  • 1. Coulombe PA. Discovery of keratin function and role in genetic diseases: the year that 1991 was. Kozminski KG, ed. Molecular Biology of the Cell. 2016;27(18):2807-2810. doi:10.1091/mbc.e15-09-0625
  • 2. Porter RM. The New Keratin Nomenclature. Journal of Investigative Dermatology. 2006;126(11):2366-2368. doi:10.1038/sj.jid.5700532
  • 3. Barak V, Goike H, Panaretakis KW, Einarsson R. Clinical utility of cytokeratins as tumor markers. Clinical Biochemistry. 2004;37(7):529-540. doi:10.1016/j.clinbiochem.2004.05.009