2009-02-25Zeitschriftenartikel DOI: 10.1074/jbc.M900773200
Cross-talk between type three secretion system and metabolism in Yersinia.
Pathogenic yersiniae utilize a type three secretion system (T3SS) to inject Yop proteins into host cells in order to undermine their immune response. YscM1 and YscM2 proteins have been reported to be functionally equivalent regulators of the T3SS in Yersinia enterocolitica. Here, we show by affinity purification, native gel electrophoresis and small angle x-ray scattering that both YscM1 and YscM2 bind to phosphoenolpyruvate carboxylase (PEPC) of Y. enterocolitica. Under in vitro conditions, YscM1, but not YscM2, was found to inhibit PEPC with an apparent IC(50) of 4 mum (K(i) = 1 mum). To analyze the functional roles of PEPC, YscM1, and YscM2 in Yop-producing bacteria, cultures of Y. enterocolitica wild type and mutants defective in the formation of PEPC, YscM1, or YscM2, respectively, were grown under low calcium conditions in the presence of [U-(13)C(6)]glucose. The isotope compositions of secreted Yop proteins and nine amino acids from cellular proteins were analyzed by mass spectrometry. The data indicate that a considerable fraction of oxaloacetate used as precursor for amino acids was derived from [(13)C(3)]phosphoenolpyruvate by the catalytic action of PEPC in the wild-type strain but not in the PEPC(-) mutant. The data imply that PEPC is critically involved in replenishing the oxaloacetate pool in the citrate cycle under virulence conditions. In the YscM1(-) and YscM2(-) mutants, increased rates of pyruvate formation via glycolysis or the Entner-Doudoroff pathway, of oxaloacetate formation via the citrate cycle, and of amino acid biosynthesis suggest that both regulators trigger the central metabolism of Y. enterocolitica. We propose a "load-and-shoot cycle" model to account for the cross-talk between T3SS and metabolism in pathogenic yersiniae.
Dateien zu dieser Publikation
Anzeige der Publikationen mit ähnlichem Titel, Autor, Urheber und Thema.
2005-06-20ZeitschriftenartikelViral promoters can initiate expression of toxin genes introduced into Escherichia coli Lewin, Astrid; Mayer, Martin; Chusainow, Janet; Jacob, Daniela; Appel, BerndBackground: The expression of recombinant proteins in eukaryotic cells requires the fusion of the coding region to a promoter functional in the eukaryotic cell line. Viral promoters are very often used for this purpose. ...
2013-08-08ZeitschriftenartikelCytomegalovirus Downregulates IRE1 to Repress the Unfolded Protein Response Stahl, Sebastian; Burkhart, Julia M.; Hinte, Florian; Tirosh, Boaz; Mohr, Hermine; Zahedi, René P.; Sickmann, Albert; Ruzsics, Zsolt; Budt, Matthias; Brune, WolframDuring viral infection, a massive demand for viral glycoproteins can overwhelm the capacity of the protein folding and quality control machinery, leading to an accumulation of unfolded proteins in the endoplasmic reticulum ...
2010-05-01ZeitschriftenartikelDifferential expression of human endogenous retrovirus K transcripts in primary human melanocytes and melanoma cell lines after UV irradiation. Reiche, Janine; Pauli, Georg; Ellerbrok, HeinzHuman endogenous retroviruses (HERVs) are discussed as causative agents of various diseases including cancers. Expression of endogenous retroviral sequences can be induced by ultraviolet (UV) light, which is also considered ...