Transcriptional Regulation of Membrane Lipid Homeostasis in Escherichia coli*

The biophysical properties of membrane phospholipids are controlled by the composition of their constituent fatty acids and are tightly regulated in Escherichia coli. The FabR (fatty acid biosynthesis repressor) transcriptional repressor controls the proportion of unsaturated fatty acids in the membrane by regulating the expression of the fabB (β-ketoacyl-ACP synthase I) and fabA (β-hydroxydecanoyl-ACP dehydratase/isomerase) genes. FabR binding to a DNA palindrome located within the promoters of the fabB and fabA genes required the presence of an unsaturated acyl-acyl carrier protein (ACP) or acyl-CoA and was antagonized by saturated acyl-ACP or acyl-CoA. The FabR-dependent repression of fabB and fabA by exogenous unsaturated fatty acids confirmed the role for FabR in responding to the acyl-CoA pool composition, and the perturbation of the unsaturated:saturated acyl-ACP ratio using a specific inhibitor of lipid A formation verified FabR-dependent regulation of fabB by the acyl-ACP composition in vivo. Thus, FabR plays a key role in controlling the membrane biophysical properties by regulating gene expression in response to the composition of the long-chain acyl-thioester pool. This mechanism ensures that a balanced composition of fatty acids is available for incorporation into the membrane via the PlsB/PlsC acyltransferases.

[1]  C. DiRusso,et al.  Characterization of FadR, a global transcriptional regulator of fatty acid metabolism in Escherichia coli. Interaction with the fadB promoter is prevented by long chain fatty acyl coenzyme A. , 1992, The Journal of biological chemistry.

[2]  Alex E. Lash,et al.  Gene Expression Omnibus: NCBI gene expression and hybridization array data repository , 2002, Nucleic Acids Res..

[3]  C. DiRusso,et al.  Analysis of Acyl Coenzyme A Binding to the Transcription Factor FadR and Identification of Amino Acid Residues in the Carboxyl Terminus Required for Ligand Binding (*) , 1995, The Journal of Biological Chemistry.

[4]  C. Rock,et al.  Ratio of active to inactive forms of acyl carrier protein in Escherichia coli. , 1983, The Journal of biological chemistry.

[5]  N. W. Davis,et al.  The complete genome sequence of Escherichia coli K-12. , 1997, Science.

[6]  W. J. Dyer,et al.  A rapid method of total lipid extraction and purification. , 1959, Canadian journal of biochemistry and physiology.

[7]  C. Rock,et al.  Regulation of coenzyme A biosynthesis , 1981, Journal of bacteriology.

[8]  Pei Zhou,et al.  Structure of the deacetylase LpxC bound to the antibiotic CHIR-090: Time-dependent inhibition and specificity in ligand binding , 2007, Proceedings of the National Academy of Sciences.

[9]  Diego de Mendoza,et al.  FapR, a bacterial transcription factor involved in global regulation of membrane lipid biosynthesis. , 2003, Developmental cell.

[10]  G. von Heijne,et al.  Materials and Methods Figs. S1 to S3 References and Notes Global Topology Analysis of the Escherichia Coli Inner Membrane Proteome , 2022 .

[11]  H. Mori,et al.  Construction of Escherichia coli K-12 in-frame, single-gene knockout mutants: the Keio collection , 2006, Molecular systems biology.

[12]  Regulation of phospholipid synthesis in Escherichia coli. Composition of the acyl-acyl carrier protein pool in vivo. , 1982, The Journal of biological chemistry.

[13]  J. W. Campbell,et al.  The Enigmatic Escherichia coli fadE Gene Is yafH , 2002, Journal of bacteriology.

[14]  C. Rock,et al.  Acyl-Acyl Carrier Protein Regulates Transcription of Fatty Acid Biosynthetic Genes via the FabT Repressor in Streptococcus pneumoniae* , 2009, The Journal of Biological Chemistry.

[15]  F. Neidhardt,et al.  Escherichia Coli and Salmonella: Typhimurium Cellular and Molecular Biology , 1987 .

[16]  R. Heath,et al.  The FadR·DNA Complex , 2001, The Journal of Biological Chemistry.

[17]  C. Rock,et al.  Acetoacetyl-acyl carrier protein synthase, a potential regulator of fatty acid biosynthesis in bacteria. , 1987, The Journal of biological chemistry.

[18]  Alejandro Buschiazzo,et al.  Structural basis of lipid biosynthesis regulation in Gram‐positive bacteria , 2006, The EMBO journal.

[19]  D. de Mendoza,et al.  A malonyl‐CoA‐dependent switch in the bacterial response to a dysfunction of lipid metabolism , 2008, Molecular microbiology.

[20]  C. Rock,et al.  Two aerobic pathways for the formation of unsaturated fatty acids in Pseudomonas aeruginosa , 2006, Molecular microbiology.

[21]  C. Rock,et al.  Preparative enzymatic synthesis and hydrophobic chromatography of acyl-acyl carrier protein. , 1979, The Journal of biological chemistry.

[22]  S Omura,et al.  Inhibition of fatty acid synthesis by the antibiotic cerulenin. Specific inactivation of beta-ketoacyl-acyl carrier protein synthetase. , 1973, Biochimica et biophysica acta.

[23]  J. W. Campbell,et al.  Escherichia coli FadR Positively Regulates Transcription of the fabB Fatty Acid Biosynthetic Gene , 2001, Journal of bacteriology.

[24]  C. Rock,et al.  Membrane lipid homeostasis in bacteria , 2008, Nature Reviews Microbiology.

[25]  B. Wattenberg,et al.  Conditions influencing formation of 16:0/16:0 molecular species in membrane phospholipids of Escherichia coli. , 1983, The Journal of biological chemistry.

[26]  J. Cronan,et al.  Escherichia coli Unsaturated Fatty Acid Synthesis , 2009, The Journal of Biological Chemistry.

[27]  B. Booth.  Cell surface proteins of E. coli. , 1980, Biochemical and biophysical research communications.

[28]  C. Rock,et al.  Transcriptional regulation of fatty acid biosynthesis in Streptococcus pneumoniae , 2006, Molecular microbiology.

[29]  C. Rock,et al.  Regulation of pantothenate kinase by coenzyme A and its thioesters. , 1987, The Journal of biological chemistry.

[30]  C. Rock,et al.  A Pseudomonas aeruginosa transcription factor that senses fatty acid structure , 2007, Molecular microbiology.

[31]  Pei Zhou,et al.  Inhibition of lipid A biosynthesis as the primary mechanism of CHIR-090 antibiotic activity in Escherichia coli. , 2007, Biochemistry.

[32]  C. Rock,et al.  Prediction of Mechanisms of Action of Antibacterial Compounds by Gene Expression Profiling , 2004, Antimicrobial Agents and Chemotherapy.

[33]  J. Cronan,et al.  A new mechanism of transcriptional regulation: Release of an activator triggered by small molecule binding , 1992, Cell.

[34]  K. Bloch,et al.  On the enzymatic synthesis of unsaturated fatty acids in Escherichia coli. , 1967, Proceedings of the National Academy of Sciences of the United States of America.

[35]  J. Rudolph,et al.  A slow, tight-binding inhibitor of the zinc-dependent deacetylase LpxC of lipid A biosynthesis with antibiotic activity comparable to ciprofloxacin. , 2005, Biochemistry.

[36]  C. Rock,et al.  The FabR (YijC) Transcription Factor Regulates Unsaturated Fatty Acid Biosynthesis in Escherichia coli * , 2002, The Journal of Biological Chemistry.