Structure-based functional analysis of effector protein SifA in living cells reveals motifs important for Salmonella intracellular proliferation
Namakchian M, Kaßler K, Sticht H, Hensel M, Deiwick J (2018)
Publication Type: Journal article
Publication year: 2018
Journal
Book Volume: 308
Pages Range: 84-96
Journal Issue: 1
DOI: 10.1016/j.ijmm.2017.09.004
Abstract
The facultative intracellular pathogen Salmonella enterica survives and replicates inside the Salmonella-containing vacuole (SCV) of mammalian host cells. SifA is a key effector protein translocated by a type III secretion system and involved in formation of Salmonella-induced filaments (SIF), extensive tubular endosomal compartments. Recruitment of LAMP1 (lysosomal-associated membrane protein 1)-positive membranes to SIF ensures integrity and dynamics of the membrane network. The binding of SifA to the host protein SKIP (SifA and kinesin interacting protein) was proposed as crucial for this function. Due to structural mimicry SifA has further been proposed to interact with G-proteins. We conducted a mutational study of SifA to identify domains and amino acid residues specifically relevant for intracellular replication and SIF formation. Mutations were designed based on the available structural data of SifA and its interface with SKIP, or modeled for SifA as putative guanine nucleotide exchange factor. We developed a live cell imaging-based approach for volume quantification of the SIF network that allowed determination of subtle changes in SIF network and performed a comprehensive analysis of mutant forms of SifA by this approach. We found that the SifA catalytic loop of WxxxE effectors is as important for SIF formation and intracellular proliferation as the SKIP interaction motif, or the CAAX motif for membrane anchoring of SifA.
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Germany (DE)How to cite
APA:
Namakchian, M., Kaßler, K., Sticht, H., Hensel, M., & Deiwick, J. (2018). Structure-based functional analysis of effector protein SifA in living cells reveals motifs important for Salmonella intracellular proliferation. International Journal of Medical Microbiology, 308(1), 84-96. https://dx.doi.org/10.1016/j.ijmm.2017.09.004
MLA:
Namakchian, Mahsa, et al. "Structure-based functional analysis of effector protein SifA in living cells reveals motifs important for Salmonella intracellular proliferation." International Journal of Medical Microbiology 308.1 (2018): 84-96.
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