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Understanding virulence factors of Mycoplasma penetrans: attachment organelle organization and gene expression

Distelhorst, Steven Lindau
http://rave.ohiolink.edu/etdc/view?acc_num=miami149060747354379

Abstract Details

2017, Doctor of Philosophy, Miami University, Microbiology.
The ability to establish and maintain cell polarity plays an important role in cellular organization for both functional and morphological integrity in eukaryotic and prokaryotic organisms. Like eukaryotes, bacteria, including the genomically reduced species of the Mycoplasma genus, use an array of cytoskeletal proteins to generate and maintain cellular polarity. Some mycoplasmas, such as Mycoplasma penetrans, exhibit a distinct polarized structure, known as the attachment organelle (AO), which is used for attachment to host cells and motility. The M. penetrans AO, like AOs of other mycoplasmas, contains a cytoskeletal structure at the core, but lacks any homologs of identified AO core proteins of other investigated mycoplasmas. To characterize the composition of the M. penetrans AO cytoskeleton we purified the detergent-insoluble core material and examined its structure using scanning electron microscopy and cryo-electron tomography. The ultrastructure of the M. penetrans AO core was distinct from those of other mycoplasmas. We identified several proteins from the detergent-insoluble fractions using mass spectrometry. Among twelve proteins identified four likely structural proteins had coding genes that were identified as members of a six-gene operon. Sequence analysis of these six proteins, along with another protein identified as a likely AO component, revealed predicted properties similar to AO cytoskeletal proteins from Mycoplasma pneumoniae, a member of a different phylogenetic cluster, despite a lack of sequence homology. These data support the hypothesis that AOs have independent evolutionary origins, but also suggest convergent evolution of AO organization at the molecular level. The genes encoding these M. penetrans AO proteins were found conserved in the closely related species Mycoplasma iowae. Because M. penetrans is currently genetically intractable whereas M. iowae can be genetically manipulated, we attempted to examine the localization of a homolog of one of the proteins from this cytoskeletal operon. Although our attempts to localize one of these structural proteins were unsuccessful, we constructed a plasmid that can be used to generate a chimera of these proteins via translational fusion with GFP for future studies. We also examined gene expression in M. penetrans cells grown in both the presence and absence of HeLa cells. There was very little significant difference in gene expression between the two conditions, suggesting that M. penetrans cells express the genes needed for early infection even in the absence of HeLa cells. Based on the data from these studies we propose a model for the growth and development of the M. penetrans AO core.
Mitchell Balish (Advisor)
124 p.
Microbiology
Bacteria; Mycoplasma; attachment organelle; cytoskeleton

Recommended Citations

Citations

  • Distelhorst, S. L. (2017). Understanding virulence factors of Mycoplasma penetrans: attachment organelle organization and gene expression [Doctoral dissertation, Miami University]. OhioLINK Electronic Theses and Dissertations Center. http://rave.ohiolink.edu/etdc/view?acc_num=miami149060747354379

    APA Style (7th edition)

  • Distelhorst, Steven. Understanding virulence factors of Mycoplasma penetrans: attachment organelle organization and gene expression. 2017. Miami University, Doctoral dissertation. OhioLINK Electronic Theses and Dissertations Center, http://rave.ohiolink.edu/etdc/view?acc_num=miami149060747354379.

    MLA Style (8th edition)

  • Distelhorst, Steven. "Understanding virulence factors of Mycoplasma penetrans: attachment organelle organization and gene expression." Doctoral dissertation, Miami University, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=miami149060747354379

    Chicago Manual of Style (17th edition)

miami149060747354379
424
© 2017, some rights reserved.Creative Commons License Understanding virulence factors of Mycoplasma penetrans: attachment organelle organization and gene expression by Steven Lindau Distelhorst is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Unported License. Based on a work at etd.ohiolink.edu.
This open access ETD is published by Miami University and OhioLINK.