Sigma factors in sporulation. Sporulation: regulated sigma factor cascade. … but what regulates the sigma factors?. Not transcriptional control What kind of post-transcriptional control? How are events coordinated? Checkpoints?.
Sporulation: regulated sigma factor cascade
… but what regulates the sigma factors?
Sigma GKellner, E.M., Decatur, A., and Moran, C. (1996). Two-Stage Regulation of an Anti-Sigma Factor Determines Developmental Fate During Bacterial Endospore Formation. Molecular Microbiology, 21(5), 913-924.
Why and How?
Backtrack to E
Does G requirespoIIIA to be present
in order to be active?
spoIIIA is required for G activity
(Kirchman et al., 1993; Rather et al., 1990; Foulger et al., 1993)
SpoIIAB + E. coli
SpoIIAB + E. coli w/
…Test with mutant G that does not bind efficiently to SpoIIAB
How are SpoIIAB and spoIIIA related?
What would happen if the G mutant was combined with a spoIIIA mutant? How would G activity be effected?
In spoIIIA mutant:
E155K mutant G is active
in a spoIIIA mutant!!
spoIIIA relieves the inhibition of
G activity by SpoIIAB
E155K mutantdoes not require
SpoIIIA for its activation.