Associate Professor of Microbiology
Office Location: Health Sciences E-313
Campus Box: 357735
Dr. Lara holds a B.S. and an M.S. from the California State University, Los Angeles, in Microbiology, and a Ph.D. in biology from the University of California, Riverside. His postdoctoral training was conducted at the University of California, San Diego.
Research in Dr. Lara’s laboratory is directed at studying the synthesis and regulation of gas vesicles in the aquatic bacterium Ancylobacter aquaticus. These intracellular gas-containing protein inclusions provide buoyancy, thus allowing the organism to position itself vertically in a water column.
Recently the laboratory has demonstrated that motile (flagellated) variants can be isolated from gas vacuolate strains of A. aquaticus. These motile variants no longer express the gas vesicle phenotype. However, in certain variant strains the motile phenotype is unstable. At a frequency of 10-2 these cells revert back to producing gas vesicles with a concomitant loss of motility. This switching between gas vesicle and flagella expression is reminiscent of the flagella phase variation seen in S. typhimurium, and the fimbriae/pili synthesis in E. coli and N. gonorrhoeae. The laboratory’s current research activities are directed at determining if a common regulatory mechanism exists which governs expression of these two structures.
Katze, M. G, J. Lara, M. Wambach. Nontranslated cellular mRNAs are associated with the cytoskeletal framework in influenza virus or adenovirus infected cell. Virology 169:312-322, 1989.
Totten, P.A., Lara, J.C., and Lory, S. The rpoN gene product of Pseudomonas aeruginosa is required for expression of diverse genes, including the flagellin gene. J. Bacteriol., 172:389-396, 1990.
Ramphel, R., Koo, L., Ishimoto, K.S., Totten, P.A., Lara, J.C., and Lory, S. Adhesion of Pseudomonas aeruginosa pilin deficient mutants to mucin, infection and immunity, 59:1307-1311, 1991.
Battisti, L., Lara, J.C., Leigh, J.A. Specific oligosaccharide form of the Rhizobium meliloti exopolysaccharide promotes nodule invasion in alfalfa. PNAS, 89:1-7, 1992.
Jelesko, J. G., Lara, J. C., and Leigh, J. A. Rhizobium meliloti mutants with decreased DAHP synthase activity are sensitive to exogenous tryptophan and phenylalanine and form ineffective nodules. Molec. Plant-Microbe Interactions 6: (in press) 1993.