Noordally Zeenat, Land Lara, Trichtinger Celso, Dalvit Ivan, de Meyer Mireille, Wang Kai, Fitzpatrick Teresa B
Vitamins and Environmental Stress Responses in Plants, Department of Plant Sciences, University of Geneva, 1211 Geneva, Switzerland.
iScience. 2023 Feb 3;26(3):106134. doi: 10.1016/j.isci.2023.106134. eCollection 2023 Mar 17.
Metabolic homeostasis is regulated by enzyme activities, but the importance of regulating their corresponding coenzyme levels is unexplored. The organic coenzyme thiamine diphosphate (TDP) is suggested to be supplied as needed and controlled by a riboswitch-sensing mechanism in plants through the circadian-regulated gene. Riboswitch disruption negatively impacts plant fitness. A comparison of riboswitch-disrupted lines to those engineered for enhanced TDP levels suggests that time-of-day regulation of expression particularly under light/dark cycles is crucial. Altering the phase of expression to be synchronous with TDP transporters disrupts the precision of the riboswitch implying that temporal separation of these processes by the circadian clock is important for gauging its response. All defects are bypassed by growing plants under continuous light conditions, highlighting the need to control levels of this coenzyme under light/dark cycles. Thus, consideration of coenzyme homeostasis within the well-studied domain of metabolic homeostasis is highlighted.
代谢稳态由酶活性调节，但其相应辅酶水平调节的重要性尚未得到探索。有机辅酶硫胺素二磷酸（TDP）被认为是按需供应的，并通过昼夜节律调节基因在植物中由核糖开关感应机制控制。核糖开关破坏对植物适应性有负面影响。将核糖开关破坏的品系与为提高TDP水平而设计的品系进行比较表明，特别是在光/暗周期下，表达的时间调节至关重要。将表达阶段改变为与TDP转运蛋白同步会破坏核糖开关的精度，这意味着昼夜节律时钟对这些过程的时间分离对于衡量其反应很重要。在连续光照条件下种植植物可以绕过所有缺陷，这突出了在光/暗周期下控制这种辅酶水平的必要性。因此，在深入研究的代谢稳态领域内强调了对辅酶稳态的考虑。
