Characterization of genes involved in the endonuclear infection process
of Holospora obtusa
Brigge, T., Lehmann, H., Goertz, H.D.
Institute for Biology, Zoology Department, University of Stuttgart, Pfaffenwaldring 57,
D-70550 Stuttgart, Germany
Paramecium caudatum may be infected by bacteria of the genus Holospora. These bacteria colonize specifically micro- or macronuclei of their host and belong to the alpha group of Proteobacteria, as determined by 16S-rRNA analysis. Holospora bacteria exist in two different forms, a reproductive one, only found in nuclei, and a morphologically distinct infectious form
able to infect other Paramecium cells. Interested in bacterial proteins functional in the infection process we isolated stage-specific polypeptides of Holospora obtusa which could be localized immunocytochemically in the periplasm of infectious forms. Aminoterminal microsequencing of some of these proteins served for screening a genomic DNA library of H. obtusa. Sequencing of two Holospora genes showed homology to genes involved in bacterial protein transport. So Holospora bacteria seem to be dependant on a very effective translocation system based on these proteins. Another stage-specific gene was found by screening with monoclonal antibodies for a 14 kD periplasmic protein. Homology search showed no relation to any other bacterial gene sequences but an ORF including a signal peptide sequence of 21 amino acids.
| LOCATION |
DATE |
TIME |
| Lecture Hall I |
Wednesday, April 8 |
09:00 am |