| 11. |
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| 12. |
- Cousin, C., et al.
(författare)
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Protein-serine/threonine/tyrosine kinases in bacterial signaling and regulation
- 2013
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Ingår i: FEMS Microbiology Letters. - : Oxford University Press (OUP). - 1574-6968 .- 0378-1097. ; 346:1, s. 11-19
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Forskningsöversikt (refereegranskat)abstract
- In this review, we address some recent developments in the field of bacterial protein phosphorylation, focusing specifically on serine/threonine and tyrosine kinases. We present an overview of recent studies outlining the scope of physiological processes that are regulated by phosphorylation, ranging from cell cycle, growth, cell morphology, to metabolism, developmental phenomena, and virulence. Specific emphasis is placed on Mycobacterium tuberculosis as a showcase organism for serine/threonine kinases, and Bacillus subtilis to illustrate the importance of protein phosphorylation in developmental processes. We argue that bacterial serine/threonine and tyrosine kinases have a distinctive feature of phosphorylating multiple substrates and might thus represent integration nodes in the signaling network. Some open questions regarding the evolutionary benefits of relaxed substrate selectivity of these kinases are treated, as well as the notion of nonfunctional background' phosphorylation of cellular proteins. We also argue that phosphorylation events for which an immediate regulatory effect is not clearly established should not be dismissed as unimportant, as they may have a role in cross-talk with other post-translational modifications. Finally, recently developed methods for studying protein phosphorylation networks in bacteria are briefly discussed.
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| 13. |
- Istrate, C, et al.
(författare)
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Bone marrow dendritic cells internalize live RF-81 bovine rotavirus and rotavirus-like particles (RF 2/6-GFP-VLP and RF 8*2/6/7-VLP) but are only activated by live bovine rotavirus
- 2007
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Ingår i: Scandinavian Journal of Immunology. - : Wiley. - 0300-9475 .- 1365-3083. ; 65:6, s. 494-502
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Tidskriftsartikel (refereegranskat)abstract
- Dendritic cells (DC) represent the link between innate and adaptive immunity. They are classified as antigen-presenting cells (APC) and can initiate and modulate the immune response. To investigate the interaction with DCs, live RF-81 bovine rotavirus strain (RFV) and rotavirus-like particles (rota-VLP), RF 2/6-GFP-VLP and rota RF 8*2/6/7-VLP, were added in vitro to murine bone marrow-derived DCs (bmDCs). Live RFV, RF 2/6-GFP-VLP and RF 8*2/6/7-VLP all bound to bmDC and were internalized but only live RFV stimulated phenotypic maturation of the bmDCs as shown by the upregulation of the co-stimulatory molecule CD86. Even though bmDCs internalized RF 2/6-GFP-VLP and RF 8*2/6/7-VLP as efficiently as live RFV, these rota-VLP were not able to activate the cells. Supernatants derived from bmDC cultures treated with live RFV, RF 2/6-GFP-VLP or RF 8*2/6/7-VLP were examined for TNF-α production. At 6, 18 and 24 h post-infection, TNF-α concentrations were significantly increased in cultures treated with live RFV and rota-VLP compared with untreated cultures. In conclusion, this study showed that live RF-81 bovine rotavirus strain was internalized and induced bmDCs activation, whereas both RF 2/6-GFP-VLP and RF 8*2/6/7-VLP were internalized by bmDCs without triggering their activation. © 2007 The Authors.
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| 14. |
- Kobir, A., et al.
(författare)
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Phosphorylation of Bacillus subtilis gene regulator AbrB modulates its DNA-binding properties
- 2014
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Ingår i: Molecular Microbiology. - : Wiley. - 1365-2958 .- 0950-382X. ; 92:5, s. 1129-1141
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Tidskriftsartikel (refereegranskat)abstract
- AbrB is a global gene regulator involved in transition phase phenomena in Bacillus subtilis. It participates in a complex regulatory network governing the expression of stationary-phase functions. AbrB was previously found to be phosphorylated on serine 86 located close to its C-terminal oligomerization domain. Here we report that AbrB can be phosphorylated by three B. subtilis serine/threonine kinases expressed during the transition and stationary phase: PrkC, PrkD and YabT. Our in vitro findings suggest that AbrB phosphorylation impedes its DNA binding and abolishes binding cooperativity. In vivo we established that a phospho-mimetic mutation abrB S86D leads to a significant loss of AbrB control over several key target functions: exoprotease production, competence development and sporulation. A wider transcriptome analysis of abrBS86D and S86A mutant strains revealed deregulation of a large number of target genes. We therefore propose that AbrB phosphorylation serves as an additional input for fine-tuning the activity of this ambiactive gene regulator.
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| 15. |
- Vildevall, Malin, et al.
(författare)
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Human antibody responses to bovine (Newbury-2) norovirus (GIII.2) and association to histo-blood group antigens.
- 2010
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Ingår i: Journal of medical virology. - : Wiley. - 1096-9071 .- 0146-6615. ; 82:7, s. 1241-6
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Tidskriftsartikel (refereegranskat)abstract
- Serum antibodies to bovine norovirus have been found recently in about 22% of humans. Whether this prevalence reflects limited virulence properties of the virus or that inherited host factors provide protection against bovine norovirus infection in humans remains to be established. To investigate whether histo-blood group antigens correlate with the presence of bovine norovirus (GIII.2) antibody, plasma (n = 105) from Swedish blood donors, genotyped and phenotyped for secretor, Lewis and ABO, were tested and compared for the frequency of IgG antibody and antibody titer to Bo/Newbury2/76/UK. In total, 26.7% (28/105) of Swedish blood donors were antibody-positive. Two non-secretors (2/21, 9.5%) were antibody-positive compared with 26/84 (31%) secretors (P = 0.047). While no statistically significant correlation was found between the frequency of antibodies to bovine norovirus and different ABO blood groups, individuals with blood type B presented the highest frequency of antibodies (37.5%) compared with 0-30% among other blood groups. Individuals with Le(a-b+) had not only higher frequency of antibodies (31.3%) compared with Le(a+b-) (11%) (P = 0.068) but also higher antibody titer (P = 0.085) although this was not significant statistically. No detectable cross-reaction between bovine GIII.2 and human GII.3 NoV VLP was found with human and animal sera. The results of this study suggest that bovine norovirus infections occur in Sweden and that secretor status but not ABO blood groups is a possible risk factor for infection.
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