Author
|
Submitted to: Biochimica et Biophysica Acta
Publication Type: Review Article Publication Acceptance Date: 3/14/2016 Publication Date: 3/18/2016 Publication URL: https://handle.nal.usda.gov/10113/62904 Citation: Allen, D.K. 2016. Assessing compartmentalized flux in lipid metabolism with isotopes. Biochimica et Biophysica Acta. doi:10.1016/j.bbalip.2016.03.017. Interpretive Summary: Technical Abstract: Metabolism in plants takes place across multiple cell types and subpopulations in distinct organelles. The distributions equate to spatial heterogeneity; though the limited means to experimentally asses metabolism frequently involve homogenizing tissues and mixing metabolites from different locations. Most current isotope investigations of metabolism therefore lack the ability to resolve spatially distinct events. Recognition of this limitation has resulted in inspired efforts to advance metabolic flux analysis and isotopic labeling techniques. Though a number of these efforts have been applied to studies in central metabolism; recent advances in instrumentation and techniques present an untapped opportunity to make similar progress in lipid metabolism where the use of stable isotopes has been more limited. These efforts will benefit from sophisticated radiolabeling reports that continue to enrich our knowledge on lipid biosynthetic pathways and provide some direction for stable isotope experimental design and extension of MFA to this area. Evidence for this assertion is presented through the review of several elegant stable isotope studies and by taking stock of what has been learned from radioisotope investigations when spatial aspects of metabolism were considered. The studies emphasize that glycerolipid production occurs across several locations with assembly of lipids in the ER or plastid, fatty acid biosynthesis occurring in the plastid, and the generation of acetyl-CoA and glycerol-3-phosphate taking place in the plastid and cytosol. Considering metabolism in this context underscores the cellular and subcellular organization that is important to enhanced production of glycerolipids in plants. |
