YEASTERDAY 2010
New hot paper: Sugar sensing and signaling in plants: Conserved and novel mechanisms
“Certificat of Honor” van de Stichting voor Alzheimer OnderzoekLaboratory of Functional Biology
The laboratory of Functional Biology is divided into three groups.
Prof. Joris Winderickx : Yeast Biotechnology group.
Nutrient-induced signal transduction in yeast.
In this research line, the main target is to understand the regulatory network that links the sensing of different nutrients, such as carbon, nitrogen, amino acid and phosphate, to the control of gene expression, metabolism, stress resistance and growth in yeast. Although we and others made already considerable progress in the field of nutrient-induced signalling, most studies were limited to the identification of the proteins involved and the elucidation of their relation from the view point of linear signalling cascades. Hence, our current approach does not only deal with the top-down elucidation of single nutrient-responsive pathways but also with the more global unravelling of nutrient signalling networks and the characterization of converging effector-branches of the pathways in yeast. This should provide an explanation for the dynamical and very coordinated nutritional response.
Yeast cells as versatile model systems.
This second line of research originated from the finding that different yeast nutrient-sensitive signalling cascades are at the origin of the more sophisticated pathways found in higher eukaryotes, where hormonal control have assumed increasingly greater importance. This led us to use yeast cells to demonstrate the regulatory properties of plant and mammalian proteins. Subsequently, we also started to develop humanized model systems that allowed studying various molecular aspects associated with different human diseases where our current focus is on models for neurological disorders related to tau and α-synuclein.
Prof. Jan Geuns : Plant Physiology group.
The laboratory of plant physiology studies the physiological and biochemical processes in higher plants. Some practical applications are covered : the study of apical dominance has its own application in ornamental plants (e.g. azalea). The research on Stevia Rebaudiana finds its use in the nutrition industry. Stevioside can be used as a sweetener for diabetics and in addition is exempt of calories. The study of cryopreservation of meristems is related to the preservation of the world collection of over 1000 banana cultivars. The study of the effects of heavy metals can be used in the control of soil contamination (think of the recent discovered cases of soil pollution).
- Study of Stevia and the extraction of stevioside
- Apical Dominance
- Analysis of the meristem cultures of banana after a preculture on media with high sugar concentration and the correlation with the cryopreservation capacity
- Mung bean seedlings as indicator of soil contamination
- Toxicological studies
Prof. Filip Rolland : Plant Metabolic Signaling group.
Plants support life on earth with their unique ability to produce sugars and oxygen by solar energy-driven photosynthesis. However, plants are constantly challenged with changing environmental conditions and, as sessile organisms, depend on the ability to accurately monitor and adapt to these changes for optimal growth and survival. In addition, they now also need to deal with surging CO2 concentrations in the atmosphere and rapid climate change. Photosynthesis and primary carbon metabolism generate a variety of ‘sugar signals’ that interact with environmental, hormonal, and other metabolic cues to modulate the most vital processes in pants throughout their entire life cycle, ensuring an optimal use of the energy resources. In the past decade, significant progress has been made in elucidating the role of sugars as regulatory molecules in plants and the molecular sensing and signaling mechanisms involved. Significantly, the Arabidopsis HXK1 protein, the first enzyme in glycolysis, was found to function as a conserved glucose sensor independently from its catalytic glucose phosphorylation activity. Situations of plenty are, however, much less common for plants than those of scarcity and little is known about how plants sense and adapt to darkness in the daily light–dark cycle, or to unpredictable environmental stresses that compromise photosynthesis and respiration and deplete energy supplies.
Using a combination of cellular and systems screens, we have recently shown that the Arabidopsis thaliana SnRK1 protein kinases, KIN10 and KIN11 act as evolutionarily conserved ‘fuel gauges’ controlling the convergent reprogramming of transcription in response to seemingly unrelated stress conditions. Coping with starvation is obviously a challenge for all organisms, and intimate relationships between energy availability and cell growth, stress tolerance, survival, and longevity have been observed in other models. The universal nature of this challenge is reflected by the high degree of evolutionary conservation in the regulatory mechanisms of eukaryotic energy homeostasis.
The lab is interested in further elucidating the SnRK1 signaling pathway and its role in controlling plant metabolism, development and stress resistance. Major objectives are i) the identification of the different (upstream) mechanisms controlling SnRK1 activity in response to the metabolic status, ii) the identification of (downstream) transcriptional and post-transcriptional mechanisms involved in SnRK1-regulation of sucrose and starch metabolism, iii) identification of the role of cell-autonomous SnRK1 signaling in the metabolic control of leaf development and iv) identification of the role and mechanisms of SnRK1 signaling in plant stress resistance and defense.
