B.A., Harvard University, 1948
M.D., Harvard University, 1948
Research Statement
The
polyamines, putrescine, spermidine, and spermine, are major
polybasic compounds in all living cells. These amines have been
shown to be important for many systems related to growth and
differentiation. We have been interested in how these polyamines
are synthesized, how their biosynthesis and degradation are
regulated, their physiologic functions, and how they act in
vivo. For this purpose we have constructed null mutants in each
of the biosynthetic steps in both Escherichia coli and in
Saccharomyces cerevisiae. These mutants are unable to make these
amines, and hence they are very useful tools to study the
physiological effects due to their deprivation. Our present
studies are directed at extending our studies on the
biochemistry, regulation, and genetics of these amines and of the
biosynthetic enzymes in S. cerevisiae. Our older work plus our
current work has demonstrated that the polyamines are required
for growth of the organisms, for sporulation, for maintenance of
the killer dsRNA virus, for protection against oxidative
damage, for protection against elevated temperatures, for
fidelity of protein biosynthesis, and for the maintenance of
mitochondria. Clones have been constructed that overproduce the
various enzymes, and the sequence and structural characteristics
of these enzymes have been studied. We have concentrated
particularly on the structure and regulation of ornithine
decarboxylase, spermidine synthase, spermine synthase, and
S-adenosylmethionine decarboxylase.
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Publications
1. Hamasaki-Katagiri N Katagiri Y Tabor CW Tabor H Spermine is not essential for growth of Saccharomyces cerevisiae: identification of the SPE4 gene (spermine synthase) and characterization of a spe4 deletion mutant. Gene (210): 195-201, 1998. [Full Text/Abstract]
2. Balasundaram D Dinman JD Wickner RB Tabor CW Tabor H Spermidine deficiency increases +1 ribosomal frameshifting efficiency and inhibits Ty1 retrotransposition in Saccharomyces cerevisiae. Proc Natl Acad Sci U S A (91): 172-6, 1994. [Full Text/Abstract]
3. Xie QW Tabor CW Tabor H Deletion mutations in the speED operon: spermidine is not essential for the growth of Escherichia coli. Gene (126): 115-7, 1993. [Full Text/Abstract]
4. Xie QW Tabor CW Tabor H Ornithine decarboxylase in Saccharomyces cerevisiae: chromosomal assignment and genetic mapping of the SPE1 gene. Yeast (6): 455-60, 1990. [Full Text/Abstract]
5. Tabor CW Tabor H The speEspeD operon of Escherichia coli. Formation and processing of a proenzyme form of S-adenosylmethionine decarboxylase. J Biol Chem (262): 16037-40, 1987. [Full Text/Abstract]
