Regulation of the First Committed Step in Lipopolysaccharide Biosynthesis Catalyzed by LpxC Requires the Essential Protein LapC (YejM) and HslVU Protease
We previously showed that lipopolysaccharide (LPS) assembly requires the essential LapB protein to regulate FtsH-mediated proteolysis of LpxC protein that catalyzes the first committed step in the LPS synthesis. To further understand the essential function of LapB and its role in LpxC turnover, mult...
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MDPI AG
2020-11-01
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| Series: | International Journal of Molecular Sciences |
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| author | Daria Biernacka Patrycja Gorzelak Gracjana Klein Satish Raina |
| author_facet | Daria Biernacka Patrycja Gorzelak Gracjana Klein Satish Raina |
| author_sort | Daria Biernacka |
| collection | DOAJ |
| description | We previously showed that lipopolysaccharide (LPS) assembly requires the essential LapB protein to regulate FtsH-mediated proteolysis of LpxC protein that catalyzes the first committed step in the LPS synthesis. To further understand the essential function of LapB and its role in LpxC turnover, multicopy suppressors of Δ<i>lapB</i> revealed that overproduction of HslV protease subunit prevents its lethality by proteolytic degradation of LpxC, providing the first alternative pathway of LpxC degradation. Isolation and characterization of an extragenic suppressor mutation that prevents lethality of Δ<i>lapB</i> by restoration of normal LPS synthesis identified a frame-shift mutation after 377 aa in the essential gene designated <i>lapC</i>, suggesting LapB and LapC act antagonistically. The same <i>lapC</i> gene was identified during selection for mutations that induce transcription from LPS defects-responsive <i>rpoE</i>P3 promoter, confer sensitivity to LpxC inhibitor CHIR090 and a temperature-sensitive phenotype. Suppressors of <i>lapC</i> mutants that restored growth at elevated temperatures mapped to <i>lapA</i>/<i>lapB</i>, <i>lpxC</i> and <i>ftsH</i> genes. Such suppressor mutations restored normal levels of LPS and prevented proteolysis of LpxC in <i>lapC</i> mutants. Interestingly, a <i>lapC</i> deletion could be constructed in strains either overproducing LpxC or in the absence of LapB, revealing that FtsH, LapB and LapC together regulate LPS synthesis by controlling LpxC amounts. |
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| series | International Journal of Molecular Sciences |
| spelling | doaj.art-c142b65f60a048ab9aecbd71a1f807d22023-11-20T22:51:26ZengMDPI AGInternational Journal of Molecular Sciences1661-65961422-00672020-11-012123908810.3390/ijms21239088Regulation of the First Committed Step in Lipopolysaccharide Biosynthesis Catalyzed by LpxC Requires the Essential Protein LapC (YejM) and HslVU ProteaseDaria Biernacka0Patrycja Gorzelak1Gracjana Klein2Satish Raina3Unit of Bacterial Genetics, Gdansk University of Technology, 80-233 Gdansk, PolandUnit of Bacterial Genetics, Gdansk University of Technology, 80-233 Gdansk, PolandUnit of Bacterial Genetics, Gdansk University of Technology, 80-233 Gdansk, PolandUnit of Bacterial Genetics, Gdansk University of Technology, 80-233 Gdansk, PolandWe previously showed that lipopolysaccharide (LPS) assembly requires the essential LapB protein to regulate FtsH-mediated proteolysis of LpxC protein that catalyzes the first committed step in the LPS synthesis. To further understand the essential function of LapB and its role in LpxC turnover, multicopy suppressors of Δ<i>lapB</i> revealed that overproduction of HslV protease subunit prevents its lethality by proteolytic degradation of LpxC, providing the first alternative pathway of LpxC degradation. Isolation and characterization of an extragenic suppressor mutation that prevents lethality of Δ<i>lapB</i> by restoration of normal LPS synthesis identified a frame-shift mutation after 377 aa in the essential gene designated <i>lapC</i>, suggesting LapB and LapC act antagonistically. The same <i>lapC</i> gene was identified during selection for mutations that induce transcription from LPS defects-responsive <i>rpoE</i>P3 promoter, confer sensitivity to LpxC inhibitor CHIR090 and a temperature-sensitive phenotype. Suppressors of <i>lapC</i> mutants that restored growth at elevated temperatures mapped to <i>lapA</i>/<i>lapB</i>, <i>lpxC</i> and <i>ftsH</i> genes. Such suppressor mutations restored normal levels of LPS and prevented proteolysis of LpxC in <i>lapC</i> mutants. Interestingly, a <i>lapC</i> deletion could be constructed in strains either overproducing LpxC or in the absence of LapB, revealing that FtsH, LapB and LapC together regulate LPS synthesis by controlling LpxC amounts.https://www.mdpi.com/1422-0067/21/23/9088lipopolysaccharideLapBLapCYejMLpxCHslV/U protease |
| spellingShingle | Daria Biernacka Patrycja Gorzelak Gracjana Klein Satish Raina Regulation of the First Committed Step in Lipopolysaccharide Biosynthesis Catalyzed by LpxC Requires the Essential Protein LapC (YejM) and HslVU Protease International Journal of Molecular Sciences lipopolysaccharide LapB LapC YejM LpxC HslV/U protease |
| title | Regulation of the First Committed Step in Lipopolysaccharide Biosynthesis Catalyzed by LpxC Requires the Essential Protein LapC (YejM) and HslVU Protease |
| title_full | Regulation of the First Committed Step in Lipopolysaccharide Biosynthesis Catalyzed by LpxC Requires the Essential Protein LapC (YejM) and HslVU Protease |
| title_fullStr | Regulation of the First Committed Step in Lipopolysaccharide Biosynthesis Catalyzed by LpxC Requires the Essential Protein LapC (YejM) and HslVU Protease |
| title_full_unstemmed | Regulation of the First Committed Step in Lipopolysaccharide Biosynthesis Catalyzed by LpxC Requires the Essential Protein LapC (YejM) and HslVU Protease |
| title_short | Regulation of the First Committed Step in Lipopolysaccharide Biosynthesis Catalyzed by LpxC Requires the Essential Protein LapC (YejM) and HslVU Protease |
| title_sort | regulation of the first committed step in lipopolysaccharide biosynthesis catalyzed by lpxc requires the essential protein lapc yejm and hslvu protease |
| topic | lipopolysaccharide LapB LapC YejM LpxC HslV/U protease |
| url | https://www.mdpi.com/1422-0067/21/23/9088 |
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