title: Metabolic reprogramming during purine stress in the protozoan pathogen Leishmania donovani.
abstract: The ability of Leishmania to survive in their insect or mammalian host is dependent upon an ability to sense and adapt to changes in the microenvironment. However, little is known about the molecular mechanisms underlying the parasite response to environmental changes, such as nutrient availability. To elucidate nutrient stress response pathways in Leishmania donovani, we have used purine starvation as the paradigm. The salvage of purines from the host milieu is obligatory for parasite replication; nevertheless, purine-starved parasites can persist in culture without supplementary purine for over three months, indicating that the response to purine starvation is robust and engenders parasite survival under conditions of extreme scarcity. To understand metabolic reprogramming during purine starvation we have employed global approaches. Whole proteome comparisons between purine-starved and purine-replete parasites over a 6-48 h span have revealed a temporal and coordinated response to purine starvation. Purine transporters and enzymes involved in acquisition at the cell surface are upregulated within a few hours of purine removal from the media, while other key purine salvage components are upregulated later in the time-course and more modestly. After 48 h, the proteome of purine-starved parasites is extensively remodeled and adaptations to purine stress appear tailored to deal with both purine deprivation and general stress. To probe the molecular mechanisms affecting proteome remodeling in response to purine starvation, comparative RNA-seq analyses, qRT-PCR, and luciferase reporter assays were performed on purine-starved versus purine-replete parasites. While the regulation of a minority of proteins tracked with changes at the mRNA level, for many regulated proteins it appears that proteome remodeling during purine stress occurs primarily via translational and/or post-translational mechanisms.
authors.affiliation: Department of Biochemistry & Molecular Biology, Oregon Health & Science University, Portland, Oregon, United States of America.
authors.forename: Jessica L
authors.initials: JL
authors.lastname: Martin
authors.affiliation: Department of Biochemistry & Molecular Biology, Oregon Health & Science University, Portland, Oregon, United States of America.
authors.forename: Phillip A
authors.initials: PA
authors.lastname: Yates
authors.affiliation: Department of Biochemistry & Molecular Biology, Oregon Health & Science University, Portland, Oregon, United States of America.
authors.forename: Radika
authors.initials: R
authors.lastname: Soysa
authors.affiliation: Division of Biological Sciences, Pacific Northwest National Laboratory, Richland, Washington, United States of America.
authors.forename: Joshua F
authors.initials: JF
authors.lastname: Alfaro
authors.affiliation: Division of Biological Sciences, Pacific Northwest National Laboratory, Richland, Washington, United States of America.
authors.forename: Feng
authors.initials: F
authors.lastname: Yang
authors.affiliation: Division of Biological Sciences, Pacific Northwest National Laboratory, Richland, Washington, United States of America.
authors.forename: Kristin E
authors.initials: KE
authors.lastname: Burnum-Johnson
authors.affiliation: Division of Biological Sciences, Pacific Northwest National Laboratory, Richland, Washington, United States of America.
authors.forename: Vladislav A
authors.initials: VA
authors.lastname: Petyuk
authors.affiliation: Division of Biological Sciences, Pacific Northwest National Laboratory, Richland, Washington, United States of America.
authors.forename: Karl K
authors.initials: KK
authors.lastname: Weitz
authors.affiliation: Division of Biological Sciences, Pacific Northwest National Laboratory, Richland, Washington, United States of America.
authors.forename: David G
authors.initials: DG
authors.lastname: Camp
authors.affiliation: Division of Biological Sciences, Pacific Northwest National Laboratory, Richland, Washington, United States of America.
authors.forename: Richard D
authors.initials: RD
authors.lastname: Smith
authors.affiliation: Department of Biochemistry & Molecular Biology, Oregon Health & Science University, Portland, Oregon, United States of America ; Proteomics Shared Resource Core, Oregon Health & Science University, Portland, Oregon, United States of America.
authors.forename: Phillip A
authors.initials: PA
authors.lastname: Wilmarth
authors.affiliation: Department of Biochemistry & Molecular Biology, Oregon Health & Science University, Portland, Oregon, United States of America ; Proteomics Shared Resource Core, Oregon Health & Science University, Portland, Oregon, United States of America.
authors.forename: Larry L
authors.initials: LL
authors.lastname: David
authors.affiliation: Seattle Biomedical Research Institute, Seattle, Washington, United States of America.
authors.forename: Gowthaman
authors.initials: G
authors.lastname: Ramasamy
authors.affiliation: Seattle Biomedical Research Institute, Seattle, Washington, United States of America ; Department of Global Health and Department of Biomedical Informatics & Medical Education, University of Washington, Seattle, Washington, United States of America.
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Myler
authors.affiliation: Department of Biochemistry & Molecular Biology, Oregon Health & Science University, Portland, Oregon, United States of America.
authors.forename: Nicola S
authors.initials: NS
authors.lastname: Carter
mesh_terms: D002853:Chromatography, Liquid; D006801:Humans; D007893:Leishmania donovani / Q000235:genetics* / Q000378:metabolism*; D020543:Proteome / Q000378:metabolism*; D011687:Purines / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013312:Stress, Physiological / Q000502:physiology*; D053719:Tandem Mass Spectrometry
chemical_list: D020543:Proteome; D011687:Purines