title: Integrated proteomics and metabolomics suggests symbiotic metabolism and multimodal regulation in a fungal-endobacterial system.
abstract: Many plant-associated fungi host endosymbiotic endobacteria with reduced genomes. While endobacteria play important roles in these tri-partite plant-fungal-endobacterial systems, the active physiology of fungal endobacteria has not been characterized extensively by systems biology approaches. Here, we use integrated proteomics and metabolomics to characterize the relationship between the endobacterium Mycoavidus sp. and the root-associated fungus Mortierella elongata. In nitrogen-poor media, M. elongata had decreased growth but hosted a large and growing endobacterial population. The active endobacterium likely extracted malate from the fungal host as the primary carbon substrate for energy production and biosynthesis of phospho-sugars, nucleobases, peptidoglycan and some amino acids. The endobacterium obtained nitrogen by importing a variety of nitrogen-containing compounds. Further, nitrogen limitation significantly perturbed the carbon and nitrogen flows in the fungal metabolic network. M. elongata regulated many pathways by concordant changes on enzyme abundances, post-translational modifications, reactant concentrations and allosteric effectors. Such multimodal regulations may be a general mechanism for metabolic modulation.
authors.affiliation: Computer Science and Mathematics Division, Oak Ridge National Laboratory, Oak Ridge, TN, USA.|Chemical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, USA.
authors.forename: Zhou
authors.initials: Z
authors.lastname: Li
authors.affiliation: Computer Science and Mathematics Division, Oak Ridge National Laboratory, Oak Ridge, TN, USA.
authors.forename: Qiuming
authors.initials: Q
authors.lastname: Yao
authors.affiliation: Department of Chemistry, University of Tennessee, Knoxville, TN, USA.
authors.forename: Stephen P
authors.initials: SP
authors.lastname: Dearth
authors.affiliation: Graduate School of Genome Science and Technology, University of Tennessee-Oak Ridge National Laboratory, Knoxville, TN, USA.|Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, USA.
authors.forename: Matthew R
authors.initials: MR
authors.lastname: Entler
authors.affiliation: Department of Chemistry, University of Tennessee, Knoxville, TN, USA.
authors.forename: Hector F
authors.initials: HF
authors.lastname: Castro Gonzalez
authors.affiliation: Department of Biology, Duke University, Durham, NC, USA.
authors.forename: Jessie K
authors.initials: JK
authors.lastname: Uehling
authors.affiliation: Department of Biology, Duke University, Durham, NC, USA.
authors.forename: Rytas J
authors.initials: RJ
authors.lastname: Vilgalys
authors.affiliation: Chemical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, USA.
authors.forename: Gregory B
authors.initials: GB
authors.lastname: Hurst
authors.affiliation: Department of Chemistry, University of Tennessee, Knoxville, TN, USA.
authors.forename: Shawn R
authors.initials: SR
authors.lastname: Campagna
authors.affiliation: Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, USA.
authors.forename: Jessy L
authors.initials: JL
authors.lastname: Labbé
authors.affiliation: Computer Science and Mathematics Division, Oak Ridge National Laboratory, Oak Ridge, TN, USA.|Graduate School of Genome Science and Technology, University of Tennessee-Oak Ridge National Laboratory, Knoxville, TN, USA.|Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, USA.
authors.forename: Chongle
authors.initials: C
authors.lastname: Pan
mesh_terms: D042521:Burkholderiaceae / Q000378:metabolism*; D002244:Carbon / Q000378:metabolism; D053858:Metabolic Networks and Pathways; D055432:Metabolomics; D020094:Mortierella / Q000378:metabolism*; D009584:Nitrogen / Q000378:metabolism; D018517:Plant Roots / Q000382:microbiology; D011499:Protein Processing, Post-Translational; D040901:Proteomics; D013559:Symbiosis
chemical_list: D002244:Carbon; D009584:Nitrogen