Another level of complex-ity: The role of metabolic channeling and metabolons in plant terpenoid metabolism.

Terpenoids constitute one of the largest and most diverse classes of plant metabolites. While some terpenoids are involved in essential plant processes such as photosynthesis, respiration, growth, and development, others are specialized metabolites playing roles in the interaction of plants with their biotic and abiotic environment. Due to the distinct functions and properties of specific terpenoid compounds, there is a growing interest to introduce or modify their production in plants by metabolic engineering for agricultural, pharmaceutical, or industrial applications. The MVA and MEP pathways and the prenyltransferases providing the general precursors for terpenoid formation, as well as the enzymes of the various downstream metabolic pathways leading to the formation of different groups of terpenoid compounds have been characterized in detail in plants. In contrast, the molecular mechanisms directing the metabolic flux of precursors specifically toward one of several potentially competing terpenoid biosynthetic pathways are still not well understood. The formation of metabolons, multi-protein complexes composed of enzymes catalyzing sequential reactions of a metabolic pathway, provides a promising concept to explain the metabolic channeling that appears to occur in the complex terpenoid biosynthetic network of plants. Here we provide an overview about examples of potential metabolons involved in plant terpenoid metabolism that have been recently characterized and the first attempts to utilize metabolic channeling in terpenoid metabolic engineering. In addition, we discuss the gaps in our current knowledge and in consequence the need for future basic and applied research.

Effects of multiple forms of childhood abuse and adult sexual assault on current eating disorder symptoms.

The objective of this study is to examine the effect of recent adult sexual assault on current eating disorder symptoms when controlling for the effects of multiple forms of childhood abuse. A total of 489 undergraduate women completed the Eating Disorder Examination-Questionnaire, and surveys regarding childhood abuse and sexual assault that had occurred in the previous three months. Approximately 30% of the sample indicated recent unwanted sexual experiences. Childhood emotional abuse contributed unique variance to the prediction of current ED symptoms, but sexual and physical abuse did not. Recent sexual assault contributed additional unique variance to current ED symptoms when controlling for childhood abuse, thus both emotional abuse in childhood and sexual assault in adulthood contributed unique variance to ED symptoms.