Title of Oral/Poster Presentation

Development and characterization of a highly soluble construct of the Shigella flexneri translocator protein IpaC

Presenter Information

Jenna BouvangFollow

Class

Article

Graduation Year

2017

College

College of Science

Department

Chemistry and Biochemistry Department

Faculty Mentor

Nicholas Dickenson

Presentation Type

Poster Presentation

Abstract

Shigella flexneri is a Gram-negative pathogen that causes Shigellosis, a severe form of dysentery hallmarked by massive fluid loss and hemorrhaging of the intestines. Though treatable with antibiotics, shigellosis results in more than 125 million reported cases and 14,000 deaths annually. S. flexneri relies on a type three secretion system (T3SS) as its primary virulence factor. The type three secretion apparatus (T3SA) resembles a needle-like structure through which the effector proteins are injected in the cytoplasm of the eukaryotic host. The distal end of the needle is the tip complex which is a sophisticated hetero-complex responsible for interaction with the host cell membrane. This system relies on the presence of dedicated chaperone proteins that bind to effectors within the cytoplasm of the pathogen and release it upon secretion through the apparatus. The S. flexneri tip complex includes a pentamer of the hydrophilic protein IpaD which regulates secretion through the apparatus as well as the hydrophobic translocator proteins IpaB and IpaC. Both IpaB and IpaC are required for proper pore formation in the host cell membrane, though little is known about their specific roles in this interaction. The hydrophobic character of IpaC requires either a chaperone protein, IpgC, or a detergent to maintain solubility in solution. Here we identify a stable construct of IpaC, which requires neither detergent nor its chaperone to maintain solubility and perform a series of biophysical characterization experiments on both the IpaC construct alone and as a part of the chaperone-bound heterocomplex.

Location

North Atrium

Start Date

4-13-2017 10:30 AM

End Date

4-13-2017 11:45 AM

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Apr 13th, 10:30 AM Apr 13th, 11:45 AM

Development and characterization of a highly soluble construct of the Shigella flexneri translocator protein IpaC

North Atrium

Shigella flexneri is a Gram-negative pathogen that causes Shigellosis, a severe form of dysentery hallmarked by massive fluid loss and hemorrhaging of the intestines. Though treatable with antibiotics, shigellosis results in more than 125 million reported cases and 14,000 deaths annually. S. flexneri relies on a type three secretion system (T3SS) as its primary virulence factor. The type three secretion apparatus (T3SA) resembles a needle-like structure through which the effector proteins are injected in the cytoplasm of the eukaryotic host. The distal end of the needle is the tip complex which is a sophisticated hetero-complex responsible for interaction with the host cell membrane. This system relies on the presence of dedicated chaperone proteins that bind to effectors within the cytoplasm of the pathogen and release it upon secretion through the apparatus. The S. flexneri tip complex includes a pentamer of the hydrophilic protein IpaD which regulates secretion through the apparatus as well as the hydrophobic translocator proteins IpaB and IpaC. Both IpaB and IpaC are required for proper pore formation in the host cell membrane, though little is known about their specific roles in this interaction. The hydrophobic character of IpaC requires either a chaperone protein, IpgC, or a detergent to maintain solubility in solution. Here we identify a stable construct of IpaC, which requires neither detergent nor its chaperone to maintain solubility and perform a series of biophysical characterization experiments on both the IpaC construct alone and as a part of the chaperone-bound heterocomplex.