Disease relevance of flaA

• Murein-hydrolyzing activity of flagellin FlaA of Listeria monocytogenes [1].
• All isolates were biochemically identified and characterized by serotyping, phage typing, and amplification of the flaA gene by polymerase chain reaction (PCR) [2].
• Cytosolic recognition of flagellin by mouse macrophages restricts Legionella pneumophila infection [3].
• Immunization with the living, chromosomally integrated Salmonella construct carrying LLO 215-226 epitope as part of the flagellin protein generated T cells reactive with the corresponding LLO peptide, indicating that this chimera can stimulate a class-specific immune response in vitro [4].

High impact information on flaA

• Interestingly, GmaR also functions as a glycosyltransferase exhibiting O-linked N-acetylglucosamine transferase (OGT) activity for flagellin (FlaA) [5].
• Flagellin monomers appeared to trigger the macrophage response from perforated phagosomes: once heated to disassemble filaments, flagellin triggered cell death but native flagellar preparations did not [3].
• Deletion of the factor-encoding gene (lmo0674) resulted in loss of temperature-dependent flaA expression and an increase in flaA promoter activity [6].
• Indeed, a protein factor capable of specifically binding to the flaA promoter region was identified in cytoplasmic extracts of EGDe by using affinity purification and MS [6].
• Previous studies have shown that Listeria monocytogenes flagellar motility genes, including flaA, encoding flagellin, are transcriptionally down-regulated at 37 degrees C. For some L. monocytogenes strains, temperature-dependent motility gene expression is less stringent [6].

Chemical compound and disease context of flaA

• A 200-mer fragment of the flaA gene from Listeria monocytogenes was amplified using the polymerase chain reaction (PCR) incorporating biotin- and fluorescein amadite (FAM-)labelled primers [7].
• Glycan staining of purified flagellin from Listeria monocytogenes serotypes 1/2a, 1/2b, 1/2c, and 4b suggested that the flagellin protein from this organism is glycosylated [8].

Biological context of flaA

• Immediately downstream of flaA, two genes, cheY and cheA, encoding products with homology to chemotaxis proteins of other bacteria, are located [9].
• Several nucleotide sequence variations were found in the flaA, iap and hly genes [10].
• We found that the two L. monocytogenes operons encoding flagella-specific genes and the monocistronically transcribed flaA gene are positively regulated by DegU at 24 degrees C, but are not expressed at 37 degrees C [11].
• The most stable structure obtained in this search, an alpha-helical conformation, was shown to form the electrostatic interactions Glu552-Gln89, Asp555-Arg92, and Arg558-Glu93 with the predicted binding site of the flagellin of S. enterica serovar Typhimurium, formed by the 88-to-97 chain fragment (LQRVRELAVQ), which is likewise alpha helical [12].
• The chimeric flagellin genes were integrated into the chromosome of the flagellin-negative S. dublin strain to obtain stable expression of the epitopes [4].

Anatomical context of flaA

• The flagellum protein flagellin of Listeria monocytogenes is encoded by the flaA gene [9].
• Flagellin made L. pneumophila vulnerable to innate immune mechanisms because Naip5(+) macrophages restricted the growth of virulent microbes, but flagellin mutants replicated freely [3].

Associations of flaA with chemical compounds

• Mass spectrometry analysis demonstrated that the flagellin protein of L. monocytogenes is posttranslationally modified with O-linked N-acetylglucosamine (GlcNAc) at up to six sites/monomer [8].

Other interactions of flaA

• Northern blot analysis showed that expression of flaA and lmaA mRNAs was reduced in the dnaK mutant, THY-LK1 [13].
• Class II (LLO 215-226) or class I (LLO 91-99) MHC-restricted T-cell epitopes of LLO were inserted within a central, hypervariable domain of the flagellin protein of an attenuated delta aroA Salmonella dublin strain [4].

Analytical, diagnostic and therapeutic context of flaA

• Whole organisms grown at 20 degrees C and 37 degrees C were examined in Western blots using an affinity-purified polyclonal antibody, and a monoclonal antibody, both directed against 29 kDa putative flagellin [14].
• No flagella were seen on serotype 7 by electron microscopy and no flagellin was detected in crude cell surface extracts of serotype 7 either in silver-stained gels or in Western blots [15].

References