Sigma Xi Poster Competition
Academic Level at Time of Presentation
Junior
Major
Exercise Science
Minor
Biology
List all Project Mentors & Advisor(s)
Christopher Lennon, PhD.
Presentation Format
Poster Presentation
Abstract/Description
Intervening proteins, or inteins, are mobile genetic elements translated within host polypeptides and removed at the protein level by splicing. In protein splicing, a selfmediated reaction removes the intein, leaving only a peptide bond in place. While protein splicing can proceed in the absence of external co-factors, several natural examples of conditional protein splicing (CPS) have emerged. In CPS, the rate and accuracy of splicing is highly-dependent on environmental conditions. As activity of the intein-containing host protein is compromised prior to splicing, and inteins are highly abundant in the microbial world, CPS represents an emerging form of post-translational regulation that is potentially widespread in microbes. Reactive chlorine species (RCS) are highly-potent oxidants encountered by bacteria in a variety of natural environments, including within cells of the mammalian innate immune system. Here, we demonstrate that two naturally occurring RCS, the active compound in bleach, hypocholorous acid, and N-Chlorotaurine, can reversibly block splicing of DnaB inteins from Mycobacterium leprae and Mycobacterium smegmatis in vitro. Further, using a reporter that monitors DnaB intein activity within M. smegmatis, we show that DnaB protein splicing is inhibited by RCS in the native host. DnaB, an essential replicative helicase, is the most common intein-housing protein in bacteria. These results add to the growing list of environmental conditions relevant to the survival of the intein-containing host that influence protein splicing, as well as suggest a novel mycobacterial response to RCS. We propose a model whereby DnaB splicing, and therefore replication, can be reversibly paused when these mycobacteria encounter RCS in nature.
Spring Scholars Week 2023 Event
Sigma Xi Poster Competition
Included in
Reactive Chlorine Species Reversibly Inhibit DnaB Protein Splicing in Mycobacteria
Intervening proteins, or inteins, are mobile genetic elements translated within host polypeptides and removed at the protein level by splicing. In protein splicing, a selfmediated reaction removes the intein, leaving only a peptide bond in place. While protein splicing can proceed in the absence of external co-factors, several natural examples of conditional protein splicing (CPS) have emerged. In CPS, the rate and accuracy of splicing is highly-dependent on environmental conditions. As activity of the intein-containing host protein is compromised prior to splicing, and inteins are highly abundant in the microbial world, CPS represents an emerging form of post-translational regulation that is potentially widespread in microbes. Reactive chlorine species (RCS) are highly-potent oxidants encountered by bacteria in a variety of natural environments, including within cells of the mammalian innate immune system. Here, we demonstrate that two naturally occurring RCS, the active compound in bleach, hypocholorous acid, and N-Chlorotaurine, can reversibly block splicing of DnaB inteins from Mycobacterium leprae and Mycobacterium smegmatis in vitro. Further, using a reporter that monitors DnaB intein activity within M. smegmatis, we show that DnaB protein splicing is inhibited by RCS in the native host. DnaB, an essential replicative helicase, is the most common intein-housing protein in bacteria. These results add to the growing list of environmental conditions relevant to the survival of the intein-containing host that influence protein splicing, as well as suggest a novel mycobacterial response to RCS. We propose a model whereby DnaB splicing, and therefore replication, can be reversibly paused when these mycobacteria encounter RCS in nature.