PI: Beth Lazazzera

Office Phone: 310-794-4804

Lab Phone: (310)794-4986

Office: Molecular Sciences   4610B

Lab: Molecular Sciences  4550-4560

Email:

bethl@em.ucla.edu

 

Supplementary Data:

J Bacteriol. vol 185 pp.1951-7

Stanley et al. 2003



Mol Microbiol. vol. 52(3)pp.847-60

Hamon et al. 2004

(Table 4)


Click here for UCLA Access page

Research Interest:



The research in the Lazazzera lab. falls within two main subjects: Cell-cell signaling and Biofilm Development

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


CSLM analysis of wild-type, spo0A and spo0A abrB mutant strains of B . subtilis expressing GFP. Biofilms of cells expressing GFP from a multicopy plasmid were grown on the surface of glass coverslides and then analysed by CSLM. A, C and E. Standard projections of the biofilms; each image is a compilation of 25 sections through the X-Y plane. Scale bars represent 20 m. B, D and F. A single section through the X-Z plane. Scale bars represent 10 m. A representative image of those obtained on at least three independent occasions is shown. A and B. BAL682 (wild-type) biofilms grown for 48 h. C and D. BAL685 (spo0A) biofilms grown for 72 h. E and F. BAL690 (spo0A abrB) biofilms grown for 48 h.
For more information see Hamon MA, Lazazzera BA.

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:

Cynthia Lee

Stephanie Lino

Lazazzera Lab Photographs

The Human Members

The nonhuman members! Also known as Gladys and Oliver


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