Molecular Genetics and Cell Biology,
Committee on Genetics
B.A., Biochemistry, Pomona College, 1968
Ph.D., Biochemistry and Molecular Biology, Harvard University,1972
We would like to understand how cells
construct chloroplasts. The chloroplast is an ordered assemblage
of multi-subunit complexes, including photosynthetic reaction centers
and ribosomes, etc. We are exploiting the unique genetic properties
of the unicellular green alga Chlamydomonas to determine if the
balancing of subunit synthesis involves active genetic control.
Numerous mutants have been selected in the chloroplast enzyme ribulose-1,
5-bisphosphate carboxylase/oxygenase (RuBisCO). RuBisCo has only
two types of subunits; one encoded in the chloroplast and the other
in the nucleus, and thus, is a simple example of a complex requiring
balanced activity of both genomes. One interesting nuclear mutation
specifically destabilizes the mRNA for the chloroplast-encoded subunit.
We are using transformation methodology to identify the target within
the message responsible for its susceptibility to stability control
and to clone the mutant gene that causes degradation. Many of the
mutants have proven to be valuable for investigating the fundamental
chemical mechanisms of the photosynthetic reaction centers. Chloroplast
transformation can now be used to generate directed mutations of
individual genes. We hope to learn how the reaction center proteins
control the chemical reactions at the heart of photosynthetic energy
Qu, X., Wu, D., Mets, L. and Scherer,
N. F. (2004). "Nanometer-localized multiple single-molecule
fluorescence microscopy." Proc Natl Acad Sci U S A 101: 11298-303.
Lee, J. W., Mets, L. and Greenbau,
E. (2002). "Improvement of photosynthetic CO2 fixation at high
light intensity through reduction of chlorophyll antenna size."
Appl Biochem Biotechnol 98-100: 37-48. (PubMed)
Shu, G., Pontieri, V., Dengler, N.
G. and Mets, L. J. (1999). "Light induction of cell type differentiation
and cell-type-specific gene expression in cotyledons of a C(4) plant,
Flaveria trinervia." Plant Physiol 121: 731-41. (PubMed)
Mets, L. and J.-D. Rochaix. (1998)
"Perspectives" in J.-D. Rochaix, M. Goldschmidt-Clermont
and S. Merchant (eds): The Molecular Biology of Chloroplasts and
Mitochondria in Chlamydomonas, pp. 685-703. Kluwer Academic.
Greenbaum, E., J.W. Lee, C.V. Tevault,
S.L. Blankenship, T.G. Owens and L.J. Mets. (1997) "Photosystem
I measurements in mutants B4 and F8 of Chlamydomonas." Science
DiMagno, L., C-K. Chan, Y. Jia, M.J.
Lang, J.R. Newman, L. Mets, G.R. Fleming, and R. Haselkorn. (1995)
"Energy transfer and trapping in photosystem I reaction centers
from cyanobacteria." Proc. Natl. Acad. Sci. USA 92:2715-271.