Phosphoproteomics reveals essential regulatory roles of phosphorylation in marine oligotrophic bacteriaOA
Oligotrophic bacteria with reduced genomes have relatively few transcriptional regulators and are thought to rely more than other bacteria on post-transcriptional regulation to respond to environmental stimuli.SAR11 bacteria are the most abundant group of heterotrophic bacteria in marine planktonic systems and are a model for understanding genome reduction in other free-living microorganisms.Here,we report a comprehensive,quantitative protein phosphorylation profile for SAR11 strain HTCC1062 grown under various environmentally relevant conditions,including light/dark cycles,temperature differences,and nutrient limitations,to investigate phosphorylation dynamics in this streamlined organism.Nearly half of proteins encoded by the genome were detected in phosphorylated forms under at least one condition.1014 Ser/Thr/Tyr phosphorylation sites were observed in 1576 phosphopeptides from 555 phosphoproteins.Protein phosphorylation was concentrated in proteins for functions associated with nutrient acquisition and growth,such as ABC transporters,RNA polymerase,and ribosomal proteins.Prominent patterns in protein phosphorylation were detected across a range of culture conditions.In these cells,which previously have been shown to continuously express nearly their entire proteome,protein phosphorylation was more dynamic than protein abundance,supporting the hypothesis that post-transcriptional regulation by protein phosphorylation might play a large role in modulating protein activity.Our findings support a regulatory model characterized by minimal variation in protein expression but extensive protein phosphorylation.This model diverges from bacterial regulatory paradigms reliant on transcriptional control,and may be relevant to understanding other abundant heterotrophs with reduced genomes.
Yu Zhang;Yao‑Hui He;Zhang‑Xian Xie;Zhuo‑An Bai;Guo‑Sheng Hu;Ming‑Hua Wang;Stephen J.Giovannoni;Da‑Zhi Wang
State Key Laboratory of Marine Environmental Science/College of the Environment and Ecology,Xiamen University,Xiamen 361005,ChinaMOE Key Lab of Rare Pediatric Diseases,Hengyang Medical School,University of South China,Hengyang 421001,ChinaState Key Laboratory of Marine Environmental Science/College of the Environment and Ecology,Xiamen University,Xiamen 361005,China School of Resources and Environmental Sciences/Key Laboratory of Rural Environmental Remediation and Waste Recycling,Quanzhou Normal University,Quanzhou 362000,ChinaState Key Laboratory of Marine Environmental Science/College of the Environment and Ecology,Xiamen University,Xiamen 361005,ChinaSchool of Pharmaceutical Sciences,Fujian Provincial Key Laboratory of Innovative Drug Target Research,Xiamen University,Xiamen 361102,ChinaState Key Laboratory of Marine Environmental Science/College of the Environment and Ecology,Xiamen University,Xiamen 361005,ChinaDepartment of Microbiology,Oregon State University,Corvallis,OR 97331,USAState Key Laboratory of Marine Environmental Science/College of the Environment and Ecology,Xiamen University,Xiamen 361005,China
生物科学
Marine oligotrophSAR11 bacteriaRegulatory mechanismPhosphorylationPhosphoproteomics
《Marine Life Science & Technology》 2026 (2)
P.628-641,14
supported by the National Key R&D Program of China(No.2022YFC3105302)the National Natural Science Foundation of China through grants 41425021,42276151 and 41906087Fujian Provincial Natural Science Foundation of China(2024J01790)the China Postdoctoral Science(2019M652253)Zhang-Xian Xie is also supported by a Visiting Fellowship from State Key Laboratory of Marine Environmental Science,Xiamen University(MEL)Stephen J Giovannoni was supported by the Simons Foundation International BIOS-SCOPE program.
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