{"645215":{"#nid":"645215","#data":{"type":"event","title":"Phd Defense by Cristian Voicu Crisan","body":[{"value":"\u003Cp\u003EIn partial fulfillment of the requirements for the degree of\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u0026nbsp;\u003C\/p\u003E\r\n\r\n\u003Cp\u003EDoctor of Philosophy in Biology\u003C\/p\u003E\r\n\r\n\u003Cp\u003EIn the\u003C\/p\u003E\r\n\r\n\u003Cp\u003ESchool of Biological Sciences\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u0026nbsp;\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u003Cstrong\u003ECristian Voicu Crisan\u003C\/strong\u003E\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u0026nbsp;\u003C\/p\u003E\r\n\r\n\u003Cp\u003EWill defend his dissertation\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u0026nbsp;\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u003Cstrong\u003EAntimicrobial Dynamics of the \u003Cem\u003EVibrio cholerae\u003C\/em\u003E Type VI Secretion System\u003C\/strong\u003E\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u0026nbsp;\u003C\/p\u003E\r\n\r\n\u003Cp\u003EWednesday, March 24\u003Csup\u003Eth\u003C\/sup\u003E, 2021\u003C\/p\u003E\r\n\r\n\u003Cp\u003E11:00 AM\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u0026nbsp;\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u003Ca href=\u0022https:\/\/nam12.safelinks.protection.outlook.com\/?url=https%3A%2F%2Fbluejeans.com%2F953791122\u0026amp;data=04%7C01%7Ctatianna.richardson%40grad.gatech.edu%7Cec60f02c7c0d45cb6db408d8e402cc28%7C482198bbae7b4b258b7a6d7f32faa083%7C0%7C0%7C637510047951096226%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000\u0026amp;sdata=ssZfak%2BhKugHvZYUPIgKDjW9U91k0pLRc7OYSFOHOnc%3D\u0026amp;reserved=0\u0022\u003Ehttps:\/\/bluejeans.com\/953791122\u003C\/a\u003E\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u0026nbsp;\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u0026nbsp;\u003Cstrong\u003EThesis Advisor:\u003C\/strong\u003E\u003C\/p\u003E\r\n\r\n\u003Cp\u003EDr. Brian Hammer, Ph.D.\u003C\/p\u003E\r\n\r\n\u003Cp\u003ESchool of Biological Sciences\u003C\/p\u003E\r\n\r\n\u003Cp\u003EGeorgia Institute of Technology\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u0026nbsp;\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u003Cstrong\u003ECommittee Members:\u003C\/strong\u003E\u003C\/p\u003E\r\n\r\n\u003Cp\u003EDr. Raquel Lieberman, Ph.D.\u003C\/p\u003E\r\n\r\n\u003Cp\u003ESchool of Chemistry and Biochemistry\u003C\/p\u003E\r\n\r\n\u003Cp\u003EGeorgia Institute of Technology\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u0026nbsp;\u003C\/p\u003E\r\n\r\n\u003Cp\u003EDr. Matthew Torres, Ph.D.\u003C\/p\u003E\r\n\r\n\u003Cp\u003ESchool of Biological Sciences\u003C\/p\u003E\r\n\r\n\u003Cp\u003EGeorgia Institute of Technology\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u0026nbsp;\u003C\/p\u003E\r\n\r\n\u003Cp\u003EDr. Thomas DiChristina, Ph.D.\u003C\/p\u003E\r\n\r\n\u003Cp\u003ESchool of Biological Sciences\u003C\/p\u003E\r\n\r\n\u003Cp\u003EGeorgia Institute of Technology\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u0026nbsp;\u003C\/p\u003E\r\n\r\n\u003Cp\u003EDr. Loren Williams, Ph.D.\u003C\/p\u003E\r\n\r\n\u003Cp\u003ESchool of Chemistry and Biochemistry\u003C\/p\u003E\r\n\r\n\u003Cp\u003EGeorgia Institute of Technology\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u0026nbsp;\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u0026nbsp;\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u003Ca name=\u0022_Hlk66270323\u0022\u003EABSTRACT: \u003Cem\u003EVibrio cholerae\u003C\/em\u003E is a common bacterial inhabitant of marine ecosystems and some pathogenic strains cause life-threatening cholera disease when ingested by humans. Like approximately 25% of all Gram-negative bacteria, \u003Cem\u003EV. cholerae \u003C\/em\u003Euses the Type VI Secretion System (T6SS) to translocate cytotoxic proteins into adjacent target cells. After sequencing a diverse set of \u003Cem\u003EV. cholerae \u003C\/em\u003Eisolates, I characterized two novel T6SS toxins, which I named TleV1 and TpeV. TleV1 is a predicted phospholipase that is lethal when expressed in the periplasm of \u003Cem\u003EEscherichia coli\u003C\/em\u003E cells and kills target bacteria when delivered in a T6SS-dependent manner. Unlike other \u003Cem\u003EV. cholerae \u003C\/em\u003ET6SS effectors, TpeV does not share homology to known proteins and does not contain motifs or domains indicative of function. \u003Cem\u003EE. coli \u003C\/em\u003Ecells expressing periplasmic TpeV have a disrupted membrane potential and are permeabilized. I determined that \u003Cem\u003EV. cholerae\u003C\/em\u003E can use TpeV to permeabilize and eliminate target cells in a T6SS-dependent manner. Human, animal and plant pathogens encode \u003Cem\u003EtpeV \u003C\/em\u003Ehomologs adjacent to known T6SS genes, indicating that the toxin is a representative member of a large protein family. While many studies have investigated the regulation and toxins of the T6SS, few have examined defensive responses elicited by target cells. I demonstrated that multiple human commensal \u003Cem\u003EE. coli\u003C\/em\u003E strains, which are susceptible to killing via the T6SS, display a significant survival improvement when co-cultured with \u003Cem\u003EV. cholerae \u003C\/em\u003Ein the presence of glucose. I identified that the \u003Cem\u003EE. coli\u003C\/em\u003E glucose-responsive gene regulator CRP (\u003Cstrong\u003E\u003Cem\u003Ec\u003C\/em\u003E\u003C\/strong\u003Eyclic adenosine monophosphate \u003Cstrong\u003E\u003Cem\u003Er\u003C\/em\u003E\u003C\/strong\u003Eeceptor \u003Cstrong\u003E\u003Cem\u003Ep\u003C\/em\u003E\u003C\/strong\u003Erotein) controls resistance against T6SS attacks. \u003Cem\u003EE. coli\u003C\/em\u003E cells with a \u003Cem\u003Ecrp \u003C\/em\u003Egene disruption are protected against \u003Cem\u003EV. cholerae\u003C\/em\u003E T6SS attacks even in the absence of glucose. In conclusion, I have shown that \u003Cem\u003EV. cholerae \u003C\/em\u003Eisolates employ a diverse repertoire of T6SS toxins and described a molecule that confers resistance to T6SS attacks in \u003Cem\u003EE. coli\u003C\/em\u003E cells. My work has expanded our understanding of secreted antimicrobial proteins and the complex dynamics of interbacterial competitions.\u003C\/a\u003E\u003C\/p\u003E\r\n","summary":null,"format":"limited_html"}],"field_subtitle":"","field_summary":"","field_summary_sentence":[{"value":"Antimicrobial Dynamics of the Vibrio cholerae Type VI Secretion System"}],"uid":"27707","created_gmt":"2021-03-10 21:56:31","changed_gmt":"2021-03-10 21:56:31","author":"Tatianna Richardson","boilerplate_text":"","field_publication":"","field_article_url":"","field_event_time":{"event_time_start":"2021-03-24T12:00:00-04:00","event_time_end":"2021-03-24T14:00:00-04:00","event_time_end_last":"2021-03-24T14:00:00-04:00","gmt_time_start":"2021-03-24 16:00:00","gmt_time_end":"2021-03-24 18:00:00","gmt_time_end_last":"2021-03-24 18:00:00","rrule":null,"timezone":"America\/New_York"},"extras":[],"groups":[{"id":"221981","name":"Graduate Studies"}],"categories":[],"keywords":[{"id":"100811","name":"Phd Defense"}],"core_research_areas":[],"news_room_topics":[],"event_categories":[{"id":"1788","name":"Other\/Miscellaneous"}],"invited_audience":[{"id":"78761","name":"Faculty\/Staff"},{"id":"78771","name":"Public"},{"id":"174045","name":"Graduate students"},{"id":"78751","name":"Undergraduate students"}],"affiliations":[],"classification":[],"areas_of_expertise":[],"news_and_recent_appearances":[],"phone":[],"contact":[],"email":[],"slides":[],"orientation":[],"userdata":""}}}