| 1. |
|
|
| 2. |
|
|
| 3. |
|
|
| 4. |
- Francis, Matthew S, et al.
(author)
-
YopD of Yersinia pseudotuberculosis is translocated into the cytosol of HeLa epithelial cells : evidence of a structural domain necessary for translocation.
- 1998
-
In: Molecular Microbiology. - 0950-382X .- 1365-2958. ; 29:3, s. 799-813
-
Journal article (peer-reviewed)abstract
- Yersinia pseudotuberculosis YopB and YopD proteins are essential for translocation of Yop effector proteins into the target cell cytosol. YopB is suggested to mediate pore formation in the target cell plasma membrane, allowing translocation of Yop effector proteins, although the function of YopD is unclear. To investigate the role in translocation for YopD, a mutant strain in Y. pseudotuberculosis was constructed containing an in frame deletion of essentially the entire yopD gene. As shown recently for the Y. pestis YopD protein, we found that the in vitro low calcium response controlling virulence gene expression was negatively regulated by YopD. This yopD null mutant (YPIII/pIB621) was also non-cytotoxic towards HeLa cell monolayers, supporting the role for YopD in the translocation process. Although other constituents of the Yersinia translocase apparatus (YopB, YopK and YopN) are not translocated into the host cell cytosol, fractionation of infected HeLa cells allowed us to identify the cytosolic localization of YopD by the wild-type strain (YPIII/pIB102), but not by strains defective in either YopD or YopB. YopD was also identified by immunofluorescence in the cytoplasm of HeLa cell monolayers infected with a multiple yop mutant strain (YPIII/pIB29MEKA). These results demonstrate a dual function for YopD in negative regulation of Yop production and Yop effector translocation, including the YopD protein itself. To investigate whether an amphipathic domain near the C-terminus of YopD is involved in the translocation process, a mutant strain (YPIII/pIB155deltaD278-292) was constructed that is devoid of this region. Phenotypically, this small in frame deltayopD278-292 deletion mutant was indistinguishable from the yopD null mutant. The truncated YopD protein and Yop effectors were not translocated into the cytosol of HeLa cell monolayers infected with this mutant. The comparable regulatory and translocation phenotypes displayed by the small in frame deltayopD278-292 deletion and deltayopD null mutants suggest that regulation of Yop synthesis and Yop translocation are intimately coupled. We present an intriguing scenario to the Yersinia infection process that highlights the need for polarized translocation of YopD to specifically establish translocation of Yop effectors. These observations are contrary to previous suggestions that members of the translocase apparatus were not translocated into the host cell cytosol.
|
|
| 5. |
- Hoffknecht, A, et al.
(author)
-
Recombination of F6+ with free electrons at very low energies
- 1999
-
In: Physica Scripta. Topical Issues. ; T80B, s. 298-300
-
Journal article (peer-reviewed)abstract
- Radiative and dielectronic recombination of F6+ have been studied at the heavy ion storage ring TSR in Heidelberg. For a detailed investigation of rate enhancement effects at very low electron-ion center-of-mass energies experimental parameters such as the magnetic guiding field, the electron density and the adiabatic expansion factor of the electron beam have been varied systematically. Whereas measurements at different electron densities show no influence on the enhancement and while a variation of the expansion factor evokes the predicted behaviour, we see an increase of the enhancement with increasing axial magnetic field between 20 mT and 70 mT.
|
|
| 6. |
|
|
| 7. |
|
|
| 8. |
- Wadelius, Mia, et al.
(author)
-
Polymorphisms in NAT2, CYP2D6, CYP2C19 and GSTP1 and their association with prostate cancer
- 1999
-
In: Pharmacogenetics. - 0960-314X .- 1473-561X. ; 9:3, s. 333-40
-
Journal article (peer-reviewed)abstract
- The development of prostate cancer is dependent on heredity, androgenic influences, and exposure to environmental agents. A high intake of dietary fat is associated with an increased risk of prostate cancer, either through influence on steroid hormone profiles or through production of carcinogenic compounds that require biotransformation by enzymes. The polymorphic glutathione S-transferase (GST), N-acetyltransferase (NAT), and cytochrome P450 (CYP) enzymes are of particular interest in prostate cancer susceptibility because of their ability to metabolize both endogenous and exogenous compounds, including dietary constituents. Association between different NAT2, CYP2D6, CYP2C19 and GSTP1 genotypes and prostate cancer was studied in a Swedish and Danish case-control study comprising 850 individuals. The combined Swedish and Danish study population was analysed by polymerase chain reaction for the NAT2 alleles *4, *5A, *5B, *5C, *6 and *7, and for the CYP2D6 alleles *l, *3 and *4. The Swedish subjects were also analysed for the CYP2C19 alleles *1 and *2, and the GSTP1 alleles *A, *B and *C. No association was found between prostate cancer and polymorphisms in NAT2, CYP2D6, CYP2C19 or GSTP1. An association between CYP2D6 poor metabolism and prostate cancer was seen among smoking Danes; odds ratio 3.10 (95% confidence interval 1.07; 8.93), P = 0.03, but not among smoking Swedes; odds ratio 1.19 (95% confidence interval 0.41; 3.42), P = 0.75. Smoking is not a known risk factor for prostate cancer, and the association between CYP2D6 poor metabolism and prostate cancer in Danish smokers may have arisen by chance.
|
|
