Researcher Information

KATSU Yoshinao


Understanding endocrinology
based on animal evolution

Department of Biological Sciences, Reproductive and Developmental Biology


Understanding the origins of endocrine mechanism based on comparison of steroid hormone receptors and nuclear receptors isolated from various species

FieldComparative Endocrinology
KeywordAnimal, Steroid hormone, Steroid hormone receptor, Nuclear receptor, Molecular evolution

Introduction of Research

How did the regulatory mechanism of life activity by endocrine appear in the process of evolution? We aim to elucidate the whole picture of establishment of endocrine control mechanism.
Animals produce eggs and spermatozoa in reproductive organs and leave descendants. Sex hormones such as estrogen (female sex hormone) and androgen (male hormone) play an important role in the development of the reproductive organs, sexual differentiation and reproductive behavior. Furthermore, steroid hormones, glucocorticoid and mineralocorticoid secreted from the adrenal cortex are related to maintenance of homeostasis and stress response of the living animals. These are fat-soluble small molecule, which bind physiologically with steroid hormone receptors, a family of nuclear receptors.
Steroid hormone receptors are transcription factors that recognize certain gene sequences and control transcription in a hormone-dependent manner. We are cloning hormone receptor genes from various species. And we are conducting research to understand the fundamentals of the molecular evolution of steroid hormone receptor. In addition, we are investigating the interaction between receptor and hormone by molecular simulation analysis. Abnormalities in steroid hormone receptors cause various endocrine disorders. We hope that our research will lead to the elucidation of the mechanism of action of endocrine disorders by steroid hormone receptors, and will also lead to the development of drug discovery for endocrine disorders involving steroid hormone receptors.

Amphioxus is an excellent model to study the origin of steroid hormone action in vertebrates.
Lampreys are primitive fishlike jawless vertebrates place with hagfishes in the class Agnata.

Representative Achievements

Evolution of human, chicken, alligator, frog, and zebrafish mineralocorticoid receptors: Allosteric influence on steroid specificity, Y. Katsu, K. Oka, M.E. Baker, Science Signaling, 2018, 10, eaao1520.
Corticosteroid and progesterone transactivation of mineralocorticoid receptors from Amur sturgeon and tropical gar, A. Sugimoto, K. Oka, R. Sato, S. Adachi, M.E. Baker, Y. Katsu, Biochem J, 2016, 473, 3655-3665.
Molecular cloning and characterization of the corticoid receptors from the American alligator, K. Oka, S. Kohno, H. Urushitani, L.J.Guillette, Y. Ohta, T. Iguchi, Y. Katsu, Mol Cell Endicrinol, 2013, 365, 153-161.
Molecular cloning , characterization and chromosome mapping of reptilian estrogen receptors, Y. Katsu, K. Matsubara, S. Kohno, Y. Matsuda, M. Toriba, K. Oka, L.J. Guillette, Y. Ohta, T. Iguchi, Endocrinology, 2010, 151, 5710-5720.
Estrogen-dependent transactivation of amphioxus steroid hormone receptor via both estrogen- and androgen-response elements, Y. Katsu, K. Kubokawa, H. Urushitani, T. Iguchi, Endocrinology, 2010, 151, 639-648.

Department of Biological Sciences, Reproductive and Developmental Biology

KATSU Yoshinao


What is your dream that you want to achieve through your research?

In our laboratory, we study the principles and basic formation of endocrine system by examining various animals. In humans, various diseases related to endocrine, such as diabetes, are known. Gender identity disorder that we often hear recently may also be due to an imbalance in endocrine control system. Although our research is not directly related to the treatment of such diseases, we hope that our findings will help in developing new drugs for endocrine disorders and understanding mechanisms of endocrine disorders.

What is the research theme that you are currently focusing on?

Various hormones play an important role in the animal’s body, promoting growth, characterizing masculinity and femininity, and improving the internal environment of the body. The regulatory system of biological functions by “hormone” is called the “endocrine system”. Among them, steroid hormones play an important role and exert physiological functions by interacting on proteins called receptors. How did steroid hormones regulate the endocrine system during the evolution of animals? To find an answer to this, we analyze the steroid hormone receptors in the jawless, lamprey and the cartilaginous fish, the shark, and then compare them with those of humans and other vertebrates.

Lampreys are the ancient extant lineage of jawless fish.
Please tell us about yourself; things you are good at, your favorites, hobbies, and daily routines.

I like reading historical novels that are written based on some event or person in history. In particular, I read novels depicting people who played an active part in Sengoku period and at the end of Tokugawa period. My favorites are Ryotaro Shiba’s historical novels. I read novels not only on holidays but also in my spare time in between experiments. I am thrilled by the background of the period, the charm of the characters, and the life of the predecessors who shaped modern Japan. Can our research be marked as a new chapter in history?