Related Experiment Video
Updated: Jun 24, 2026
12:29
Generation of Null Mutants to Elucidate the Role of Bacterial Glycosyltransferases in Bacterial Motility
Published on: March 11, 2022
A Phosphorylation-Dependent Partner-Switching-Like Module Regulates a Glycosyltransferase Required for Heterocyst
Mai Harada1, Satoshi Matsuoka2, Shigeki Ehira1
1Department of Biological Sciences, Graduate School of Science, Tokyo Metropolitan University, Hachioji, Tokyo, Japan.
Molecular Microbiology
|June 23, 2026
Summary
Cyanobacteria heterocyst-specific polysaccharide (Hep) formation is controlled by a phosphorylation switch. The phosphatase HenR and kinase Alr3423 regulate the glycosyltransferase All4160, impacting Hep layer assembly.
Area of Science:
- Microbiology
- Biochemistry
- Molecular Biology
Background:
- Heterocyst-specific polysaccharide (Hep) is crucial for the heterocyst envelope in Anabaena sp. PCC 7120.
- Regulatory mechanisms governing Hep layer formation are not well understood.
Purpose of the Study:
- To elucidate the regulatory mechanisms controlling Hep layer formation in Anabaena sp. PCC 7120.
- To identify key proteins and phosphorylation events involved in Hep biosynthesis regulation.
Main Methods:
- Bacterial two-hybrid assays to identify interacting kinases.
- In vitro phosphorylation assays.
- Genetic analysis of gene deletions (henR, alr3423, all2284) and protein variants.
Main Results:
- Hep layer formation is regulated by a phosphorylation-dependent system involving HenR (phosphatase) and All4160 (glycosyltransferase).
- Phosphorylation negatively regulates All4160 function; a nonphosphorylatable variant rescues Hep formation in henR mutants.
- Alr3423, not All2284, was identified as the key kinase regulating All4160 in vivo, suppressing henR disruptant defects.
Conclusions:
- A novel phosphorylation switch controlling Hep layer formation has been identified.
- This study reveals a direct regulatory mechanism acting on a polysaccharide biosynthetic enzyme, impacting heterocyst development.
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