Lee Kroos
Research Interests
Certain bacteria undergo developmental processes that
include cell fate determination, cell to cell signaling, morphogenesis,
and cellular differentiation. We exploit the biochemical and genetic
simplicity of bacteria to explore the molecular mechanisms of gene
regulation and protein function during development. The novel mechanisms we discover are
likely to be used by many other microorganisms of medical, agricultural,
and environmental importance.
Bacillus subtilis is a soil bacterium that undergoes
development when starved. The cell is partitioned into two compartments,
the mother cell and the forespore, each of which expresses distinct sets
of genes in an ordered temporal fashion, under the control of different
sigma subunits of RNA polymerase (Fig. 1).
We are investigating the regulation of genes
that are expressed in the mother cell compartment during the later stages
of sporulation under the control of sK RNA polymerase. We have
shown that sK is first
made as an inactive precursor (pro-sK) and that processing to
the active form in the mother cell depends on a signal from the forespore.
Our current model for this novel type of signal transduction pathway is
shown in (Fig. 2). MORE
Recent Publications
Harry KH, Zhou R, Kroos L, Melville SB. 2009. Sporulation and enterotoxin (CPE) synthesis are controlled by the sporulation-specific sigma factors SigE and SigK in Clostridium perfringens. J Bacteriol. 191(8):2728-42. Link to publication
Mittal S, Kroos L. 2009. Combinatorial regulation by a novel arrangement of FruA and MrpC2 transcription factors during Myxococcus xanthus development. J Bacteriol. 191(8):2753-63.Link to publication
Zhou R, Cusumano C, Sui D, Garavito RM, Kroos L. 2009. Intramembrane proteolytic cleavage of a membrane-tethered transcription factor by a metalloprotease depends on ATP. Proc Natl Acad Sci U S A. 22;106(38):16174-9. Link to publication
Mittal S, Kroos L. 2009. A combination of unusual transcription factors binds cooperatively to control Myxococcus xanthus developmental gene expression.Proc Natl Acad Sci U S A. 106(6):1965-70. Link to publication
Kroos L. 2008. Bacterial development in the fast lane.
J Bacteriol. 190(13):4373-6. Link to publication
Daisuke I, Zhou R, Feig M, Kroos L. 2008. Evidence that the Bacillus subtilis SpoIIGA protein is a novel type of signal-transducing aspartic protease. J. Biol. Chem. 283(22):15287-99. Link to publication
Kroos L. 2007. The Bacillus and Myxococcus developmental networks and their transcriptional regulators. Annu Rev Genet. 41:13-39. Link to publication
Wang L, Perpich J, Driks A, Kroos L. 2007. Maintaining the transcription factor SpoIIID level late during sporulation causes spore defects in Bacillus subtilis. J Bacteriol. 189(20):7302-9. Link to publication
Wang L, Perpich J, Driks A, Kroos L. 2007. One perturbation of the mother cell gene regulatory network suppresses the effects of another during sporulation of Bacillus subtilis. J Bacteriol. 189(23):8467-73.Link to publication
Viswanathan P, Ueki T, Inouye S, Kroos L. 2007. Combinatorial regulation of genes essential for Myxococcus xanthus development involves a response regulator and a LysR-type regulator. Proc Natl Acad Sci U S A. 8;104(19):7969-74. Link to publication
Viswanathan P, Murphy K, Julien B, Garza AG, Kroos L. 2007. Regulation of dev, an operon that includes genes essential for Myxococcus xanthus development and CRISPR-associated genes and repeats. J Bacteriol. 189(10):3738-50. Link to publication
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