Bacterial effector proteins Flashcards
What is virulence?
Ability to cause damage to host
What do virulence factors do?
Mediate infection. They are complex and expression is dynamic (made at different times)
Pathogens that we are studying are intracellular?
Intracellular: FIRST internalized into compartments. can possibly escape
Does Legionella pneumophilia break free from vacuole (LCV)
no
What are the two types of virulence factors
Toxins and effectors
Should virulence factors be too toxic?
No, it would lead to cell death therefore bacterial death
Difference between toxins and effectors?
They are both secreted
Toxins - TOXIC effects
Effectors - NOT toxic on host.
What do toxins do?
Damage host cell
Effectors
They MANIPULATE host cell processes to mediate infection. Evolved to resemble host cell proteins. Dosen’t cause cell seath
They are SECRETED BY USUALLY A SINGLE SYSTEM
Endo vs exotoxins
Endo: active when released during division/lysis
Exo: Proteins excreted to damage host cells. immunogenic
What are GTPases?
Molecular switches. Is active when has GTP. Then, connects with host binidng partner to have cell effects.
GEF and GAP?
Activiate and deactivate respectively
What do Ras small GTPases do?
Control host processes (infection response, cytoskeleton, trafficking)
Membrane identity is dependant on
membrane lipid compositions (different types of PIs)
What do PIs on membranes do?
Help recruit host proteins for function (like trafficking, secretion, fusion)
How do effectors (EPs) interact with PIS
Bind to manipulate PI content or manipulate host protein
EPs 4 targets
Immunity
Cytoskeleton
Nuclear function
Autophagy
Eps and immunity
Use teps to reverse or finely tune immune responses to benifit pathogen
Inactivate nFkB pathway to decrease inflmmation, but control as not to cause cell death
Eps and cytoskeleton
use eps to induce uptake, cause cell-cell spread, etc.
Eps and nuclear function
express proteins to bacterias benifit, manipulate cell cycle
Eps and autophagy
Eps can make autophagy increase or decrease based on what’s wanted
Definition of autophagy/xenophagy
Remove pathogens or unneeded cell components into lysosome
