Dendritic cells (DCs) infected by Francisella tularensis are poorly activated and do not undergo classical maturation process. Although reasons of such unresponsiveness are not fully understood, their impact on the priming of immunity is well appreciated. Previous attempts to explain the behavior of Francisella-infected DCs were hypothesis-driven and focused on events at later stages of infection. Here, we took an alternative unbiased approach by applying methods of global phosphoproteomics to analyze the dynamics of cell signaling in primary DCs during the first hour of infection by Francisella tularensis Presented results show that the early response of DCs to Francisella occurs in phases and that ERK and p38 signaling modules induced at the later stage are differentially regulated by virulent and attenuated ΔdsbA strain. These findings imply that the temporal orchestration of host proinflammatory pathways represents the integral part of Francisella life-cycle inside hijacked DCs.

• MeSH
• buněčné linie MeSH
• dendritické buňky metabolismus   mikrobiologie   MeSH
• extracelulárním signálem regulované MAP kinasy metabolismus   MeSH
• fosforylace MeSH
• Francisella tularensis * MeSH
• mitogenem aktivované proteinkinasy p38 metabolismus   MeSH
• myši inbrední C57BL MeSH
• tularemie metabolismus   MeSH
• zvířata MeSH
• Check Tag
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• extracelulárním signálem regulované MAP kinasy MeSH
• mitogenem aktivované proteinkinasy p38 MeSH

The adenylate cyclase toxin (CyaA) of the whooping cough agent Bordetella pertussis subverts immune functions of host myeloid cells expressing the αMβ2 integrin (CD11b/CD18, CR3 or Mac-1). CyaA delivers into cytosol of cells an extremely catalytically active adenylyl cyclase enzyme, which disrupts the innate and adaptive immune functions of phagocytes through unregulated production of the key signaling molecule cAMP. We have used phosphoproteomics to analyze cAMP signaling of CyaA in murine bone marrow-derived dendritic cells. CyaA action resulted in alterations of phosphorylation state of a number of proteins that regulate actin cytoskeleton homeostasis, including Mena, Talin-1 and VASP. CyaA action repressed mTOR signaling through activation of mTORC1 inhibitors TSC2 and PRAS40 and altered phosphorylation of multiple chromatin remodelers, including the class II histone deacetylase HDAC5. CyaA toxin action further elicited inhibitory phosphorylation of SIK family kinases involved in modulation of immune response and provoked dephosphorylation of the transcriptional coactivator CRTC3, indicating that CyaA-promoted nuclear translocation of CRTC3 may account for CyaA-induced IL-10 production. These findings document the complexity of subversive physiological manipulation of myeloid phagocytes by the CyaA toxin, serving in immune evasion of the pertussis agent.

• MeSH
• AMP cyklický metabolismus   MeSH
• Bordetella pertussis metabolismus   MeSH
• cytoskeletální proteiny metabolismus   MeSH
• dendritické buňky metabolismus   MeSH
• fosfoprotein stimulovaný vazodilatátorem MeSH
• fosfoproteiny metabolismus   MeSH
• histondeacetylasy metabolismus   MeSH
• mikrofilamentové proteiny metabolismus   MeSH
• molekuly buněčné adheze metabolismus   MeSH
• myši inbrední C57BL MeSH
• myši MeSH
• pertuse mikrobiologie   MeSH
• signální transdukce fyziologie   MeSH
• talin metabolismus   MeSH
• transkripční faktory metabolismus   MeSH
• zvířata MeSH
• Check Tag
• myši MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• AMP cyklický MeSH
• CRTC3 protein, mouse MeSH Prohlížeč
• cytoskeletální proteiny MeSH
• Enah protein, mouse MeSH Prohlížeč
• fosfoprotein stimulovaný vazodilatátorem MeSH
• fosfoproteiny MeSH
• Hdac5 protein, mouse MeSH Prohlížeč
• histondeacetylasy MeSH
• mikrofilamentové proteiny MeSH
• molekuly buněčné adheze MeSH
• talin MeSH
• Tln1 protein, mouse MeSH Prohlížeč
• transkripční faktory MeSH

BACKGROUND: SH3 domains are eukaryotic protein domains that participate in a plethora of cellular processes including signal transduction, proliferation, and cellular movement. Several studies indicate that tyrosine phosphorylation could play a significant role in the regulation of SH3 domains. RESULTS: To explore the incidence of the tyrosine phosphorylation within SH3 domains we queried the PhosphoSite Plus database of phosphorylation sites. Over 100 tyrosine phosphorylations occurring on 20 different SH3 domain positions were identified. The tyrosine corresponding to c-Src Tyr-90 was by far the most frequently identified SH3 domain phosphorylation site. A comparison of sequences around this tyrosine led to delineation of a preferred sequence motif ALYD(Y/F). This motif is present in about 15% of human SH3 domains and is structurally well conserved. We further observed that tyrosine phosphorylation is more abundant than serine or threonine phosphorylation within SH3 domains and other adaptor domains, such as SH2 or WW domains. Tyrosine phosphorylation could represent an important regulatory mechanism of adaptor domains. CONCLUSIONS: While tyrosine phosphorylation typically promotes signaling protein interactions via SH2 or PTB domains, its role in SH3 domains is the opposite - it blocks or prevents interactions. The regulatory function of tyrosine phosphorylation is most likely achieved by the phosphate moiety and its charge interfering with binding of polyproline helices of SH3 domain interacting partners.

• MeSH
• biologická evoluce * MeSH
• fosforylace MeSH
• molekulární modely MeSH
• molekulární sekvence - údaje MeSH
• sekvence aminokyselin MeSH
• sekvenční homologie aminokyselin MeSH
• src homologní domény * MeSH
• tyrosin metabolismus   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• tyrosin MeSH