Dataset Information

Cyanobacterial proteome mapping reveals distinct compartment organisation and metabolism dispersed throughout the cell

ABSTRACT: Cyanobacteria are complex prokaryotes, incorporating a Gram-negative cell wall and internal thylakoid membranes (TM). However, localisation of proteins within cyanobacterial cells is poorly understood. Using subcellular fractionation and quantitative proteomics we report the first subcellular map of the proteome of an entire cyanobacterial (or any other prokaryotic) cell, identifying ~67% of Synechocystis sp. PCC 6803 proteins, ~1000 more than previous studies. 1,712 proteins were assigned to six specific subcellular regions. Proteins involved in energy generation localised to TMs. The majority of transporters, with the exception of the TM localised copper importer CtaA, resided in the plasma membrane (PM). Most metabolic enzymes are soluble although numerous pathways terminated in the TM (notably those involved in peptidoglycan monomer, NADP+, heme, lipid and carotenoid biosynthesis), or the PM (specifically those catalysing lipopolysaccharide, molybdopterin, flavin adenine dinucleotide and menaquinone biosynthesis). Furthermore, we identified the proteins involved in the TM and PM electron transport chains. The majority of ribosomal proteins and enzymes synthesising the storage compound polyhydroxybuyrate formed distinct clusters within the data suggesting that they have similar subcellular distributions to one another as one would expect for proteins operating within multi-component protein structures. Moreover, heterogeneity within membrane and cytoplasmic regions is observed, indicating further cellular complexity. Cyanobacterial TM protein localisation is conserved in Arabidopsis thaliana chloroplasts, suggesting similar proteome organisation in higher photosynthetic organisms. The organisation of a cyanobacterial cell revealed here will significantly aid our understanding of these environmentally and biotechnological important organisms. The successful application of this technique in Synechocystis suggests it could be applied to mapping the proteomes of other cyanobacteria and complex single-celled organisms.

INSTRUMENT(S): Orbitrap Fusion Lumos

ORGANISM(S): Bacteria Synechocystis Sp. Pcc 6803

SUBMITTER: Kathryn Lilley

LAB HEAD: Kathryn S Lilley

PROVIDER: PXD014662 | Pride | 2019-10-31

REPOSITORIES: Pride

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Proteome Mapping of a Cyanobacterium Reveals Distinct Compartment Organization and Cell-Dispersed Metabolism.

Baers Laura L LL Breckels Lisa M LM Mills Lauren A LA Gatto Laurent L Deery Michael J MJ Stevens Tim J TJ Howe Christopher J CJ Lilley Kathryn S KS Lea-Smith David J DJ

Plant physiology 20191002 4

Cyanobacteria are complex prokaryotes, incorporating a Gram-negative cell wall and internal thylakoid membranes (TMs). However, localization of proteins within cyanobacterial cells is poorly understood. Using subcellular fractionation and quantitative proteomics, we produced an extensive subcellular proteome map of an entire cyanobacterial cell, identifying ∼67% of proteins in <i>Synechocystis</i> sp. PCC 6803, ∼1000 more than previous studies. Assigned to six specific subcellular regions were 1 ...[more]

PMID: 31578229

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