A Metabolic Probe-Enabled Strategy Reveals Uptake and Protein Targets of Polyunsaturated Aldehydes in the Diatom Phaeodactylum tricornutum.
Diatoms are unicellular algae of crucial importance as they belong to the main primary producers in aquatic ecosystems. Several diatom species produce polyunsaturated aldehydes (PUAs) that have been made responsible for chemically mediated interactions in the plankton. PUA-effects include chemical defense by reducing the reproductive success of grazing copepods, allelochemical activity by interfering with the growth of competing phytoplankton and cell to cell signaling. We applied a PUA-derived molecular probe, based on the biologically highly active 2,4-decadienal, with the aim to reveal protein targets of PUAs and affected metabolic pathways. By using fluorescence microscopy, we observed a substantial uptake of the PUA probe into cells of the diatom Phaeodactylum tricornutum in comparison to the uptake of a structurally closely related control probe based on a saturated aldehyde. The specific uptake motivated a chemoproteomic approach to generate a qualitative inventory of proteins covalently targeted by the α,β,γ,δ-unsaturated aldehyde structure element. Activity-based protein profiling revealed selective covalent modification of target proteins by the PUA probe. Analysis of the labeled proteins gave insights into putative affected molecular functions and biological processes such as photosynthesis including ATP generation and catalytic activity in the Calvin cycle or the pentose phosphate pathway. The mechanism of action of PUAs involves covalent reactions with proteins that may result in protein dysfunction and interference of involved pathways.
Bioorganic Analytics, Institute for Inorganic and Analytical Chemistry, Friedrich Schiller University, Jena, Germany.
Stefanie
S
Wolfram
Department Mass Spectrometry/Proteomics, Max Planck Institute for Chemical Ecology, Jena, Germany.
Natalie
N
Wielsch
Department Mass Spectrometry/Proteomics, Max Planck Institute for Chemical Ecology, Jena, Germany.
Yvonne
Y
Hupfer
Department of Pharmaceutical and Medicinal Chemistry, Institute of Pharmacy, Friedrich Schiller University, Jena, Germany.
Bettina
B
Mönch
Biomedical Imaging, Department Microscopy, Leibniz Institute of Photonic Technology e.V., Jena, Germany.
Hui-Wen
HW
Lu-Walther
Biomedical Imaging, Department Microscopy, Leibniz Institute of Photonic Technology e.V., Jena, Germany; Institute for Physical Chemistry, Abbe Center of Photonics, Friedrich Schiller University, Jena, Germany.
Rainer
R
Heintzmann
Department of Pharmaceutical and Medicinal Chemistry, Institute of Pharmacy, Friedrich Schiller University, Jena, Germany.
Oliver
O
Werz
Department Mass Spectrometry/Proteomics, Max Planck Institute for Chemical Ecology, Jena, Germany.
Aleš
A
Svatoš
Bioorganic Analytics, Institute for Inorganic and Analytical Chemistry, Friedrich Schiller University, Jena, Germany.
Georg
G
Pohnert
D000255:Adenosine Triphosphate / Q000096:biosynthesis; D000447:Aldehydes / Q000737:chemistry*; D020418:Algal Proteins / Q000032:analysis* / Q000737:chemistry / Q000378:metabolism; D000818:Animals; D002853:Chromatography, Liquid; D033342:Copepoda / Q000502:physiology; D017377:Diatoms / Q000737:chemistry* / Q000378:metabolism; D015180:Electrophoresis, Gel, Two-Dimensional; D020387:Food Chain; D015335:Molecular Probes / Q000737:chemistry*; D058977:Molecular Sequence Annotation; D010427:Pentose Phosphate Pathway / Q000502:physiology; D010788:Photosynthesis / Q000502:physiology; D010839:Phytoplankton / Q000502:physiology; D020543:Proteome / Q000032:analysis* / Q000737:chemistry / Q000378:metabolism; D013194:Staining and Labeling / Q000379:methods; D053719:Tandem Mass Spectrometry
D000447:Aldehydes; D020418:Algal Proteins; D015335:Molecular Probes; D020543:Proteome; C057349:2,4-decadienal; D000255:Adenosine Triphosphate