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PI: Beth Lazazzera Office Phone: 310-794-4804 Lab Phone: (310)794-4986 Office: Molecular Sciences 4610B Lab: Molecular Sciences 4550-4560 Email: |
Supplementary Data: J Bacteriol. vol 185 pp.1951-7 |
Research Interest:
CELL-CELL SIGNALING
Cell-cell
signaling is a fundamental process carried out by all cell types. Bacteria communicate
with each other to coordinate such processes development, antibiotic production,
and virulence. We are studying the mechanism of cell-cell signaling in the model
gram-positive bacterium, Bacillus subtilis. B. subtilis and other gram-positive
bacteria use extracellular signaling peptides to communicate with each other.
B. subtilis secretes signaling peptides into the extracellular medium to serve as monitors of cell density. By studying the mechanism of sensing these signaling peptides, we have identified a new mechanism for signaling by a peptide. In contrast to other signaling peptides that are sensed through membrane receptors, the peptide, CSF, is actively transported into the cell where it functions intracellularly to bind to receptor proteins and regulate gene expression. The CSF peptide is also interesting because it has at least three targets inside the cell, which allows it to regulate two different developmental pathways at different concentrations of the peptide. We are currently taking genetic and biochemical approaches to determine the identity of the intracellular receptors of CSF and the mechanism of producing this small, unmodified peptide.
BIOFILM DEVELOPMENT
Bacterial
biofilms are a structured community of cells enclosed in a self-produced polymeric
matrix and adherent to an inert or living surface. Biofilms are the prevailing
state of bacteria in nature and have a significant impact in clinical settings.
We are using B. subtilis as a model organism to understand the molecular basis
of biofilm formation by Gram-positive bacteria. We have identified several transcription
factors that control biofilm formation. Through a combination of genetics and
DNA microarray analysis, we are identifying genes regulated by these transcription
factors that are contribute to biofilm formation.
The image below shows confocal scanning laser microscopy of biofilms formed by B. subtilis
Recent Publications:
Stanley NR, Lazazzera BA.
Environmental signals and regulatory pathways that influence biofilm formation.
Mol Microbiol. 2004 May;52(4):917-24.
Hamon MA, Stanley NR, Britton RA, Grossman AD, Lazazzera BA.
Identification of AbrB-regulated genes involved in biofilm formation by Bacillus
subtilis.
Mol Microbiol. 2004 May;52(3):847-60.
Stanley NR, Britton RA, Grossman AD, Lazazzera BA.
Identification of catabolite repression as a physiological regulator of biofilm
formation by Bacillus subtilis by use of DNA microarrays.
J Bacteriol. 2003 Mar;185(6):1951-7.
Pottathil M, Lazazzera BA.
The extracellular Phr peptide-Rap phosphatase signaling circuit of Bacillus
subtilis.
Front Biosci. 2003 Jan 1;8:d32-45. Review.
Hamon MA, Lazazzera BA.
The sporulation transcription factor Spo0A is required for biofilm development
in Bacillus subtilis.
Mol Microbiol. 2001 Dec;42(5):1199-209.
Lazazzera BA.
The intracellular function of extracellular signaling peptides.
Peptides. 2001 Oct;22(10):1519-27. Review.
Lazazzera BA.
Quorum sensing and starvation: signals for entry into stationary phase.
Curr Opin Microbiol. 2000 Apr;3(2):177-82. Review.
Lazazzera BA, Kurtser IG,
McQuade RS, Grossman AD.
An autoregulatory circuit affecting peptide signaling in Bacillus subtilis.
J Bacteriol. 1999 Sep;181(17):5193-200.
Lazazzera BA, Grossman AD.
The ins and outs of peptide signaling.
Trends Microbiol. 1998 Jul;6(7):288-94. Review.
Lab Members:
Geraldine Briceno – Staff Research Associate
Nathalia Cota – Graduate Student
Melanie Hamon – Graduate
Sara Lanigan – Graduate Student
Mridula Pottathil – Graduate Student
Becky Terra – Graduate Student
Nicola Stanley, Ph.D. – Postdoctoral Fellow
Stellar Undergraduate
Researchers:
Lazazzera Lab Photographs