Characterisation of the oligomerisation-dependent signalling function of the LD domain of the tarp virulence factor from Chlamydia

  • Ana Celeste Teixeira Nogueira (Student)

Student thesis: Master's Thesis

Abstract

Chlamydia species are Gram-negative obligate intracellular bacteria capable of causing several diseases in humans and animals. These pathogens have a unique biphasic development cycle that initiates with the elementary body (EB), the extracellular and metabolically inert form capable of inducing its internalization. Once inside the host cell, the EBs differentiate into a different form, the reticulate body (RB), which are the replicative and metabolically active form. The process by which the EBs invade cells is dependent on a type III secretion system effector called TarP (Translocated actin-recruiting phosphoprotein). TarP is known to modulate actin cytoskeleton by a signalling mechanism to promote bacterial invasion. Since FAK (Focal Adhesion kinase) is an important molecule in the regulation of actin dynamics, it was hypothesised that Chlamydia species have a pathway to induce activation and recruitment of FAK. Using two different approaches of inducing signalling from TarP and its derivatives, we show that a new motif within TarP is capable of recruiting FAK, vinculin and Arp2/3 leading to actin recruitment. We presented, as well, that the recruitment of these molecules are enhanced upon oligomerisation of the LD domain. Altogether, we described a new signalling pathway used by several chlamydial species.
Date of AwardMay 2012
Original languageEnglish
Awarding Institution
  • Universidade Católica Portuguesa
SupervisorRey Carabeo (Supervisor)

Designation

  • Mestrado em Microbiologia Aplicada

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