Mota, LuísBrizida, Carolina Almeida Lavado2021-03-112021-03-112021-012020http://hdl.handle.net/10362/113711Chlamydia trachomatis is an obligate intracellular bacterium that causes genital and ocular infections in humans. Its multiplication in host cells occurs exclusively inside a membrane-bound compartment, known as inclusion. To enter, multiply and exit host cells, C. trachomatis transports proteins through a type III secretion system into the host cell. These proteins include Incs, which insert into the inclusion membrane, modifying it, and manipulating the host cell in various ways. In this work, the interaction of an Inc protein (CT006) from C. trachomatis with 14-3-3 proteins of the host cell was studied. There are seven isoforms of 14-3-3 proteins known in mammals that in general have the capacity to bind to several signaling proteins, being able to regulate several cellular processes. It was observed that all 14-4-3 isoforms (β/ε/η/γ/σ/τ/ζ) are recruited to the periphery of the inclusion membrane, probably in an Inc CT006-independent-manner, but only 14-3-3β/η/γ/σ interact with Inc CT006. By analyzing the primary structure of Inc CT006 it was realized that although the protein has potential 14-3-3 binding motifs, none seems to be exclusively necessary for the interaction. However, any one of the motifs when present and active can promote the interaction. 14-3-3 proteins are also thought to interact with Inc CT006 through their conserved binding groove. In summary, this work supports the idea that 14-3-3 proteins have a relevant role in the intracellular multiplication of C. trachomatis. Future studies with C. trachomatis with the gene encoding Inc CT006 inactivated or overexpressed, and/or with host cell with reduced levels of 14-3-3 proteins, might clarify how the interaction of Inc CT006 with 14-3-3 proteins contribute to the intracellular multiplication of C. trachomatis.engChlamydia trachomatisInc CT00614-3-3 proteinsprotein-protein interactionmaster thesis