INVESTIGADORES
COMERCI Diego Jose
congresos y reuniones científicas
Título:
Protein interactions involved in cyclic â-1,2-glucans metabolism
Autor/es:
GUIDOLIN L. S.; MORRONE SEIJO S.; GUAIMAS F.; COMERCI D. J; ANDRéS E. CIOCCHINI
Lugar:
Buenos Aires
Reunión:
Simposio; First Argentinian Symposium of Glycobiology, "GlycoAR 2014"; 2014
Resumen:
Cyclic b-1,2-glucans (CbG) are periplasmic homopolysaccharides that
play an important role in several symbiotic and pathogenic relationships. Brucella abortus CbG synthase (Cgs) is an integral inner membrane
(IIM) protein which catalyzes the synthesis of CbG. Once synthesized in the cytoplasm, CbG are transported to the periplasm by the CâG
transporter (Cgt) and succinylated by the CâG modifier enzyme (Cgm). Cgt and
Cgm, as well as Cgs, are IIM proteins. In this work, we used a bacterial
two-hybrid system and co-immunoprecipitation techniques to study the
interaction network between these three IIM proteins. Our results indicate that
Cgs interacts with Cgt and Cgm, and that Cgt interacts with Cgm. We also
observe that each one of these proteins form homotypic complexes. Analyses
carried out with Cgs in-frame insertion mutants and a Cgs deletion mutant
revealed that a coiled-coil motif located in the NH-terminal domain of the
protein is important to sustain protein interactions, although other regions
may also be implicated. Finally, we performed analyses of fluorescence
microscopy and found that Cgs and Cgm are localized at the cell poles in B. abortus. We propose that Cgs, Cgt and
Cgm form an inner membrane protein complex, probably located at the poles of
bacteria, necessary to coordinate the synthesis, transport to periplasm and
succinylation of CbG