A novel mode of histone-like protein HupB regulating Sinorhizobium meliloti cell division through lysine acetylation

HU, a small, basic histone-like protein, binds to bacterial genomic DNA, influencing DNA conformation, replication, and transcription. Its acetylation is a key post-translational modification affecting its DNA-binding activity. The role of HU acetylation in regulating cell division through the cell...

Full description

Saved in:
Bibliographic Details
Main Authors: Ningning Li, Huibo Jin, Hongbo Li, Huilin Yu, Xiaoxu Wu, Tianci Zhang, Liangliang Yu, Zhaoling Qin, Li Luo
Format: Article
Language:English
Published: Elsevier 2025-01-01
Series:Current Research in Microbial Sciences
Subjects:
Online Access:http://www.sciencedirect.com/science/article/pii/S2666517425000070
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:HU, a small, basic histone-like protein, binds to bacterial genomic DNA, influencing DNA conformation, replication, and transcription. Its acetylation is a key post-translational modification affecting its DNA-binding activity. The role of HU acetylation in regulating cell division through the cell cycle regulatory system remained largely unknown. In this study, we find that stimulation of lysine acetylation or non-acetylation in HupB, a homolog of HU, differentially regulates the expression of cell cycle regulators, as well as cell growth and division in Sinorhizobium meliloti. Lys3, Lys13, and Lys83 in HupB were identified as acetylated residues by mass spectrometry. Mutating these residues to arginine (stimulating non-acetylation) in HupB impedes normal cell division, while substituting them with glycine (mimicking acetylation) allows for rapid cell duplication. The mimicry of non-acetylated HupB leads to enlarged abnormal cells, while stimulating acetylated HupB only reduces cell length. Transcription activation was observed in the mutant cells. Cell cycle regulators such as CtrA, GcrA and DnaA were differentially expressed in the mutants. HupB substitutions differentially bound to these cell cycle regulatory genes. These findings suggest that the appropriate acetylation of HupB regulates the expression of cell cycle regulators, thereby controlling S. meliloti cell division.
ISSN:2666-5174