Functional investigation of the Type IX Secretion System Regulatory Pathways in Flavobacterium johnsoniae
Start Date
15-4-2021 2:30 PM
End Date
15-4-2021 2:45 PM
Student's Major
Biological Sciences
Student's College
Science, Engineering and Technology
Mentor's Name
Yongtao Zhu
Mentor's Department
Biological Sciences
Mentor's College
Science, Engineering and Technology
Description
The Type IX Secretion System (T9SS) is a protein secretion system unique to the phylum Bacteroidetes. The T9SS is a large complex composed of several different functional proteins that extend through the inner and outer membrane of the cell. This T9SS is responsible for secretion of polysaccharide digesting enzymes, motility adhesins, and virulence factors in members of the Bacteroidetes. The T9SS gene expression is known to be regulated by a two-component system (PorX and PorY) and a Sigma Factor protein (SigP) in the human oral pathogen Porphyromonas gingivalis, a non-motile member of the phylum Bacteroidetes that causes gum diseases. When PorY receives extracellular signals, a chain reaction of phosphorylation occurs, ending with SigP, which will directly interact with T9SS encoding genes and initiate their expression. The T9SS regulation mechanisms have not been studied in other Bacteroidetes.
In this research, we aim to investigate the functions of the PorXY two component system and sigP in Flavobacterium johnsoniae, a model organism from Bacteroidetes for gliding motility and the T9SS studies. F. johnsoniae has adhesins along its outer membrane, allowing for gliding motility across solid surfaces. This organism also produces chitinase, an enzyme that digests chitin. These adhesins, as well as the chitinase, are secreted by the F. johnsoniae T9SS. We have created mutants lacking porY and sigP in F. johnsoniae by using a SacB mediated deletion system. The mutants will be tested for ability to digest chitin and use their gliding motility. The mutants may exhibit defective chitin digestion and gliding motility if porY and sigP are involved in regulating the expression of F. johnsoniae T9SS.
This functional investigation provides more information about gene regulation of a relatively novel secretion system, as well investigating possibilities for drug therapies in pathogenic species of Bacteroidetes.
Key words: Type IX Secretion System, F. johnsoniae, gliding motility, chitinase, regulation
Functional investigation of the Type IX Secretion System Regulatory Pathways in Flavobacterium johnsoniae
The Type IX Secretion System (T9SS) is a protein secretion system unique to the phylum Bacteroidetes. The T9SS is a large complex composed of several different functional proteins that extend through the inner and outer membrane of the cell. This T9SS is responsible for secretion of polysaccharide digesting enzymes, motility adhesins, and virulence factors in members of the Bacteroidetes. The T9SS gene expression is known to be regulated by a two-component system (PorX and PorY) and a Sigma Factor protein (SigP) in the human oral pathogen Porphyromonas gingivalis, a non-motile member of the phylum Bacteroidetes that causes gum diseases. When PorY receives extracellular signals, a chain reaction of phosphorylation occurs, ending with SigP, which will directly interact with T9SS encoding genes and initiate their expression. The T9SS regulation mechanisms have not been studied in other Bacteroidetes.
In this research, we aim to investigate the functions of the PorXY two component system and sigP in Flavobacterium johnsoniae, a model organism from Bacteroidetes for gliding motility and the T9SS studies. F. johnsoniae has adhesins along its outer membrane, allowing for gliding motility across solid surfaces. This organism also produces chitinase, an enzyme that digests chitin. These adhesins, as well as the chitinase, are secreted by the F. johnsoniae T9SS. We have created mutants lacking porY and sigP in F. johnsoniae by using a SacB mediated deletion system. The mutants will be tested for ability to digest chitin and use their gliding motility. The mutants may exhibit defective chitin digestion and gliding motility if porY and sigP are involved in regulating the expression of F. johnsoniae T9SS.
This functional investigation provides more information about gene regulation of a relatively novel secretion system, as well investigating possibilities for drug therapies in pathogenic species of Bacteroidetes.
Key words: Type IX Secretion System, F. johnsoniae, gliding motility, chitinase, regulation
