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Research
Interests:
My laboratory is interested
in understanding the problem of how cells divide.
My approach to this problem is to study cell division
genes in a simple organism accessible to genetic
manipulation. The organism I study is the filamentous
soil bacterium Streptomyces coelicolor. This mycelial
bacterium undergoes an elaborate cycle of cellular
differentiation similar to that of certain filamentous
fungi. During differentiation, aerial hyphal filaments
are partitioned by extensive septation to form
uninucleoid cells that further metamorphose into
chains of spores.
In unicellular bacteria, cell
division is required for growth and therefore
is essential. However, my previous results demonstrate
that septation is dispensable for vegetative growth
of S. coelicolor, but still required for subdivision
of aerial filaments during spore formation. Therefore,
the advantage of using this system is that it
is possible to isolate or construct mutants to
analyze bacterial cytokinesis as a nonessential
process using this filamentous bacterium while
similar mutants would be lethal in unicellular
organisms. I hope this approach will identify
new genes involved in cell division, particularly
those whose products are involved in imparting
the positional information as to where the future
sites of cell division will be.
Because of its complex life
cycle, S. coelicolor offers an excellent system
for studying regulation of morphological differentiation.
My results suggest that cell division has been
mainly co-opted for septation during spore formation
in this organism. A second goal of my research
is to analyze how cell division is regulated temporally
and spatially such that it occurs synchronously
in the aerial hyphae, the regions of the colony
which are destined to become spores.
Representative
Publications:
1. Bennett, J.A., Aimino, R.M. and J.R. McCormick. 2007. Streptomyces coelicolor genes ftsL and divIC play a role in cell division, but are dispensable for colony formation. Journal of Bacteriology.
189:8982-8992.
2. Bentley, S.D., S. Brown, L.D. Murphy, D.E. Harris, M.A. Quail, J. Parkhill, B.G. Barrell, J.R. McCormick , R.I. Santamaria, R. Losick, M. Yamasaki, H. Kinashi, C.W. Chen, G. Chandra, D. Jakimowicz, H.M. Kieser, T. Kieser and K.F. Chater. 2004. SCP1, a 356 023 bp linear plasmid adapted to the ecology and developmental biology of its host, Streptomyces coelicolor A3(2). Molecular Microbiology. 51 :1615-1628.
3. Grantcharova, N., W. Ubhayasekera, S.L. Mowbray, J.R. McCormick, and K. Flärdh. 2003. A missense mutation in ftsZ differentially affects vegetative and developmentally controlled cell division in Streptomyces coelicolor . Molecular Microbiology. 47 :645-656.
4. Bennett, J.A. and J.R. McCormick . 2001. Two New Loci Affecting Cell Division Identified as Suppressor s o f an ftsQ -Null Mutation in Streptomyces coelicolor A3(2). FEMS Microbiology Letters. 202 :251-256.
5. Schwedock, J., McCormick,
J. R., Angert, E. R., Nodwell, J. R. and R. Losick.
(1997) Assembly of the Cell Division Protein FtsZ
into Ladder-Like Structures in the Aerial Hyphae
of Steptomyces coelicolor. Molecular Microbiology.
25: 847-858.
6. McCormick, J.R. and R. Losick
(1996). Cell Division Gene ftsQ is required for
Efficient Sporulation but not Growth and Viability
in Streptomyces coelicolor A3(2). Journal of Bacteriology.
178: 5259-5301.
7. McCormick, J.R., E.P. Su,
A. Driks and R. Losick (1994). Growth and Viability
of Streptomyces coelicolor Mutant for the Cell
Division Gene ftsZ.Molecular Microbiology. 14:
243-254.
8. McCormick, J.R., J.M. Zengel
and L. Lindahl (1994). Correlation of Translation
Efficiency with the Decay of a lacZ mRNA in Escherichia
coli. Journal of Molecular Biology. 239: 608-622.
Office Phone: (412) 396-4775
Email: mccormick@duq.edu |
