TY - JOUR
T1 - Threonine phosphorylation fine-tunes the regulatory activity of histone-like nucleoid structuring protein in Salmonella transcription
AU - Hu, Lizhi
AU - Kong, Wei
AU - Yang, Dezhi
AU - Han, Qiangqiang
AU - Guo, Lin
AU - Shi, Yixin
N1 - Funding Information:
This work was partly supported by grants from the Natural Science Foundation of China (NSFC, #31270832 and #31221061 to LG), the National Basic Research Program of China (#2013CB911102 to LG), and the 111 Project of China (B16036 to LG). This work was also supported by start-up funds from the School of Life Sciences (for YS) and the Biodesign Institute (for WK), Arizona State University.
Publisher Copyright:
Copyright © 2019 Hu, Kong, Yang, Han, Guo and Shi. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
PY - 2019
Y1 - 2019
N2 - Histone-like nucleoid structuring protein (H-NS) in enterobacteria plays an important role in facilitating chromosome organization and functions as a crucial transcriptional regulator for global gene regulation. Here, we presented an observation that H-NS of Salmonella enterica serovar Typhimurium could undergo protein phosphorylation at threonine 13 residue (T13). Analysis of the H-NS wild-type protein and its T13E phosphomimetic substitute suggested that T13 phosphorylation lead to alterations of H-NS structure, thus reducing its dimerization to weaken its DNA binding affinity. Proteomic analysis revealed that H-NS phosphorylation exerts regulatory effects on a wide range of genetic loci including the PhoP/PhoQ-regulated genes. In this study, we investigated an effect of T13 phosphorylation of H-NS that rendered transcription upregulation of the PhoP/PhoQ-activated genes. A lower promoter binding of the T13 phosphorylated H-NS protein was correlated with a stronger interaction of the PhoP protein, i.e., a transcription activator and also a competitor of H-NS, to the PhoP/PhoQ-dependent promoters. Unlike depletion of H-NS which dramatically activated the PhoP/PhoQ-dependent transcription even in a PhoP/PhoQ-repressing condition, mimicking of H-NS phosphorylation caused a moderate upregulation. Wild-type H-NS protein produced heterogeneously could rescue the phenotype of T13E mutant and fully restored the PhoP/PhoQ-dependent transcription enhanced by T13 phosphorylation of H-NS to wild-type levels. Therefore, our findings uncover a strategy in S. typhimurium to fine-tune the regulatory activity of H-NS through specific protein phosphorylation and highlight a regulatory mechanism for the PhoP/PhoQ-dependent transcription via this post-translational modification.
AB - Histone-like nucleoid structuring protein (H-NS) in enterobacteria plays an important role in facilitating chromosome organization and functions as a crucial transcriptional regulator for global gene regulation. Here, we presented an observation that H-NS of Salmonella enterica serovar Typhimurium could undergo protein phosphorylation at threonine 13 residue (T13). Analysis of the H-NS wild-type protein and its T13E phosphomimetic substitute suggested that T13 phosphorylation lead to alterations of H-NS structure, thus reducing its dimerization to weaken its DNA binding affinity. Proteomic analysis revealed that H-NS phosphorylation exerts regulatory effects on a wide range of genetic loci including the PhoP/PhoQ-regulated genes. In this study, we investigated an effect of T13 phosphorylation of H-NS that rendered transcription upregulation of the PhoP/PhoQ-activated genes. A lower promoter binding of the T13 phosphorylated H-NS protein was correlated with a stronger interaction of the PhoP protein, i.e., a transcription activator and also a competitor of H-NS, to the PhoP/PhoQ-dependent promoters. Unlike depletion of H-NS which dramatically activated the PhoP/PhoQ-dependent transcription even in a PhoP/PhoQ-repressing condition, mimicking of H-NS phosphorylation caused a moderate upregulation. Wild-type H-NS protein produced heterogeneously could rescue the phenotype of T13E mutant and fully restored the PhoP/PhoQ-dependent transcription enhanced by T13 phosphorylation of H-NS to wild-type levels. Therefore, our findings uncover a strategy in S. typhimurium to fine-tune the regulatory activity of H-NS through specific protein phosphorylation and highlight a regulatory mechanism for the PhoP/PhoQ-dependent transcription via this post-translational modification.
KW - Bacterial signal transduction
KW - Histone-like nucleoid structuring protein (H-NS)
KW - Post-translational modification
KW - Protein threonine phosphorylation
KW - Transcriptional regulation
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UR - http://www.scopus.com/inward/citedby.url?scp=85068971329&partnerID=8YFLogxK
U2 - 10.3389/fmicb.2019.01515
DO - 10.3389/fmicb.2019.01515
M3 - Article
AN - SCOPUS:85068971329
SN - 1664-302X
VL - 10
JO - Frontiers in Microbiology
JF - Frontiers in Microbiology
IS - JUL
M1 - 1515
ER -