Plant Physiology

The Plant Physiology division ( Prof. Dr. Nico Dissmeyer) investigates why some proteins remain in cells for a long time and can perform their functions, whereas other proteins can be very short-lived – and therefore only have a limited duration of action.

Molecular control of variable protein concentrations and physiological significance

Our work focuses on targeted protein degradation in multicellular organisms and its physiological significance, as well as phenotypes associated with impaired protein quality control. We are interested in enzyme-substrate interactions and biotechnological applications of switchable protein degradation in plants. We focus on post-translational modifications and test plant responses to stress that manifest dynamically at the level of active, functional proteins.

Biochemical investigation of protein homeostasis – in test tubes and living plants

We answer our questions using biochemical, genetic, cellular and molecular biological methods, often in plant model systems or with the help of microorganisms, cell-free in vitro systems or animal cell cultures. We conduct many experiments in intact plants, such as Arabidopsis thaliana or tobacco.

Why are there short-lived proteins in cells? And long-lived ones?

Our work aims to provide a detailed description and functional (molecular) analysis of complex networks involved in plant protein quality control. We investigate the biological functions these networks perform and the problems that can be expected to arise in the event of errors (mutations). The central questions concerning protein recognition, (de)stabilisation and degradation are divided into three core areas and long-term goals. They deal

• with molecular components of plant protein quality control (core area I),
• with substrates of these molecular networks (core are II), and
• with the biotechnological application of targeted protein expression in plants (core area III).

Research findings – the N-degron pathway in developmental biology

The BIG BROTHER protein regulates cell proliferation and the overall size of organs such as leaves. Through several molecular steps, it becomes a substrate of the E3 ubiquitin ligase PROTEOLYSIS1 (PRT1) – and thus a substrate of the N-degron pathway. This molecular interaction is a feedback loop of central genetic factors of cell differentiation through proteostasis.