TY  - JOUR
A1  - Aistleitner, Karin
A1  - Heinz, Christian
A1  - Hoermann, Alexandra
A1  - Heinz, Eva
A1  - Montanaro, Jacqueline
A1  - Schulz, Frederik
A1  - Maier, Elke
A1  - Pichler, Peter
A1  - Benz, Roland
A1  - Horn, Matthias
T1  - Identification and Characterization of a Novel Porin Family Highlights a Major Difference in the Outer Membrane of Chlamydial Symbionts and Pathogens
JF  - PLoS ONE
N2  - The Chlamydiae constitute an evolutionary well separated group of intracellular bacteria comprising important pathogens of humans as well as symbionts of protozoa. The amoeba symbiont Protochlamydia amoebophila lacks a homologue of the most abundant outer membrane protein of the Chlamydiaceae, the major outer membrane protein MOMP, highlighting a major difference between environmental chlamydiae and their pathogenic counterparts. We recently identified a novel family of putative porins encoded in the genome of P. amoebophila by in silico analysis. Two of these Protochlamydia outer membrane proteins, PomS (pc1489) and PomT (pc1077), are highly abundant in outer membrane preparations of this organism. Here we show that all four members of this putative porin family are toxic when expressed in the heterologous host Escherichia coli. Immunofluorescence analysis using antibodies against heterologously expressed PomT and PomS purified directly from elementary bodies, respectively, demonstrated the location of both proteins in the outer membrane of P. amoebophila. The location of the most abundant protein PomS was further confirmed by immuno-transmission electron microscopy. We could show that pomS is transcribed, and the corresponding protein is present in the outer membrane throughout the complete developmental cycle, suggesting an essential role for P. amoebophila. Lipid bilayer measurements demonstrated that PomS functions as a porin with anion-selectivity and a pore size similar to the Chlamydiaceae MOMP. Taken together, our results suggest that PomS, possibly in concert with PomT and other members of this porin family, is the functional equivalent of MOMP in P. amoebophila. This work contributes to our understanding of the adaptations of symbiotic and pathogenic chlamydiae to their different eukaryotic hosts.
KW  - cell wall
KW  - protochlamydia amoebophila
KW  - escherichia coli
KW  - matrix protein porin
KW  - gram negative bacteria
KW  - single channel analysis
KW  - developmental cycle
KW  - mycobacterium smegmatis
KW  - monoclonal antibodies
KW  - signal peptides
Y1  - 2013
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-131176
VL  - 8
IS  - 1
ER  - 
TY  - JOUR
A1  - Buchner, Erich
A1  - Blanco Redondo, Beatriz
A1  - Bunz, Melanie
A1  - Halder, Partho
A1  - Sadanandappa, Madhumala K.
A1  - Mühlbauer, Barbara
A1  - Erwin, Felix
A1  - Hofbauer, Alois
A1  - Rodrigues, Veronica
A1  - VijayRaghavan, K.
A1  - Ramaswami, Mani
A1  - Rieger, Dirk
A1  - Wegener, Christian
A1  - Förster, Charlotte
T1  - Identification and Structural Characterization of Interneurons of the Drosophila Brain by Monoclonal Antibodies of the Würzburg Hybridoma Library
JF  - PLoS ONE
N2  - Several novel synaptic proteins have been identified by monoclonal antibodies (mAbs) of the Würzburg hybridoma library generated against homogenized Drosophila brains, e.g. cysteine string protein, synapse-associated protein of 47 kDa, and Bruchpilot. However, at present no routine technique exists to identify the antigens of mAbs of our library that label only a small number of cells in the brain. Yet these antibodies can be used to reproducibly label and thereby identify these cells by immunohistochemical staining. Here we describe the staining patterns in the Drosophila brain for ten mAbs of the Würzburg hybridoma library. Besides revealing the neuroanatomical structure and distribution of ten different sets of cells we compare the staining patterns with those of antibodies against known antigens and GFP expression patterns driven by selected Gal4 lines employing regulatory sequences of neuronal genes. We present examples where our antibodies apparently stain the same cells in different Gal4 lines suggesting that the corresponding regulatory sequences can be exploited by the split-Gal4 technique for transgene expression exclusively in these cells. The detection of Gal4 expression in cells labeled by mAbs may also help in the identification of the antigens recognized by the antibodies which then in addition to their value for neuroanatomy will represent important tools for the characterization of the antigens. Implications and future strategies for the identification of the antigens are discussed.
KW  - cell staining
KW  - drosophila melanogaster
KW  - gene expression
KW  - hybridomas
KW  - immune serum
KW  - library screening
KW  - monoclonal antibodies
KW  - neurons
Y1  - 2013
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-97109
ER  -