Researchers from Heidelberg University uncover a crucial protein in a mechanism that regulates the life of proteins
Proteins serve a variety of purposes in plants in addition to being the fundamental building blocks of life. More than 20 billion protein molecules make up a typical plant cell, helping to stabilize its structure and sustain cellular metabolism.
Researchers at Heidelberg University’s Centre for Organismal Studies have shed light on a biological process that increases the life of plant proteins. They have now discovered a crucial protein, called N-terminal acetylation, that controls this mechanism. The study’s findings were published in the journals Molecular Plant and Science Advances.
N-terminal acetylation is a chemical marker that develops during the production of proteins. Plants do this by affixing an acetic acid residue to the beginning of the protein. The majority of proteins are shielded from degradation by the so-called proteasome, a form of molecular shredder, by this acetic acid residue.
The important protein that has now been found, according to the Heidelberg researchers led by Professor Dr. Rüdiger Hell and Dr. Markus Wirtz, is known as the Huntingtin Yeast Interactor Protein K (HYPK). It promotes N-terminal acetylation, extending the lifespan of plant proteins—important for, among other things, adapting to environmental circumstances.
The Heidelberg team used thale cress (Arabidopsis thaliana) to investigate the regulation properties of the HYPK protein. Due to its well-studied genome, the plant from the family Brassicaceae is a popular model organism.
Research on genetically altered plants has shown that the life of proteins is reduced when the HYPK protein is absent and N-terminal acetylation does not take place. At the same time, the plant’s resistance to ongoing drought rises. Rüdiger Hell states, “Our current research is directed to finding out how this improved drought resistance comes about.”
In cooperation with researchers from the Chinese Academy of Sciences in Beijing (China) under the direction of Professor Dr. Yonghong Wang, the Heidelberg scientists also discovered that HYPK performs its regulatory function not only in thale cress but also in rice, one of the world’s oldest crops. The protein is also found in humans and in many fungi.
“The mechanism involved in acetylation and its control by HYPK appears to be one that developed billions of years ago and has been retained in very different organisms to this day,” explains Markus Wirtz.
The studies are being funded by the German Research Foundation.
References: “HYPK promotes the activity of the Nα-acetyltransferase A complex to determine proteostasis of nonAc-X2/N-degron–containing proteins” by Pavlína Miklánková, Eric Linster, Jean-Baptiste Boyer, Jonas Weidenhausen, Johannes Mueller, Laura Armbruster, Karine Lapouge, Carolina De La Torre, Willy Bienvenut, Carsten Sticht, Matthias Mann, Thierry Meinnel, Irmgard Sinning, Carmela Giglione, Rüdiger Hell and Markus Wirtz, 15 June 2022, Science Advances.
“OsHYPK-mediated protein N-terminal acetylation coordinates plant development and abiotic stress responses in rice” by Xiaodi Gong, Yaqian Huang, Yan Liang, Yundong Yuan, Yuhao Liu, Tongwen Han, Shujia Li, Hengbin Gao, Bo Lv, Xiahe Huang, Eric Linster, Yingchun Wang, Markus Wirtz and Yonghong Wang, 4 April 2022, Molecular Plant.