Streptococcus gordonii (S. gordonii) is being developed as a Gram-positive
expression vector for the expression of heterologous proteins. This bacterial
expression system takes advantage of the natural pathway of protein export and
anchoring on the surface of the bacterium. The expression of heterologous proteins
relies on the homologous recombination of...
Retinoic acid (RA) exerts important effects in the processes of vertebrate development, cellular growth and differentiation, and homeostasis. However, the mechanisms of action of RA in the control of cellular and developmental processes are incompletely understood, as the retinoid target genes have not been fully characterized. The goal of these...
Every cell is faced continuously with the task of transducing a vast number of external signals into appropriate intracellular responses. In mammalian cells, membrane bound receptors modulate the production of secondary messenger molecules, such as cyclic AMP (cAMP). Cell signaling through second messengers relies on the diffusion of such second...
A number of bacterial species are capable of degrading the widespread environmental pollutant trichloroethylene (TCE) via aerobic cometabolism, but cytotoxic effects that can debilitate the microorganism often accompany this transformation. In this dissertation the effects of TCE degradation on the well-studied, toluene-oxidizing bacterium Burkholderia cepacia G4 were investigated at the...
Pallidosis is a disease of strawberry identified in 1957 with an unknown etiology. Two previously uncharacterized viruses in strawberry, Strawberry pallidosis associated virus (SPaV) and Beet pseudo-yellows virus (BPYV), have been found associated with disease symptoms. The complete nucleotide sequence of both viruses was determined and molecular detection protocols developed....
Cytokinesis separates replicated chromosomes and cytoplasm into two daughter cells. In animal cells, this is achieved by the formation of a cleavage furrow that bisects the mitotic (or meiotic) spindle. It is known that the mitotic apparatus defines the cell cleavage plane. However, it is not clear how the mitotic...
Two novel and highly related C₂H₂ zinc finger proteins (CTIP1/BCL11A/EVI9 and CTIP2/BCL11B/Rit1) have been implicated in COUP-TF signaling, etiology of myeloid and lymphoid malignancies, and hematopoietic cell development. However, the precise cellular function(s) and the contribution of these proteins to neoplastic processes and hematopoietic cell development remain unknown. The goal...
PCR-based codon-specific random mutagenesis and site-specific mutagenesis were performed to construct a library of 18 amino acid changes at Arg276 in the conserved leucine-loop of the core catalytic domain of human uracil-DNA glycosylase (UNG). Each Arg276 mutant was then overproduced in E. coli cells and purified to apparent homogeneity by...
ROP GTPases are crucial regulators of pollen tube growth. The Rop GTPase family in maize consists of nine known rop genes, ropl-rop9. A subset of these genes (rop2, rop8, and rop9) are expressed in pollen. The rop2 and rop9 genes are a highly conserved duplicate gene pair of ancient origin....
It is well known that the mitochondrial genome has a much higher spontaneous mutation rate than the nuclear genome. mtDNA mutations have been identified in association with many diseases and aging. mtDNA replication continues throughout the cell cycle, even in post-mitotic cells. Therefore, a constant supply of nucleotides is required...
In this investigation we examined the molecular architecture and functions associated with the virion components of the Beet yellows virus (BYV), family Closteroviridae. The BYV virions are filamentous particles composed of two coat proteins, the major coat protein (CP), which encapsidates the majority of the genome, and the minor coat...
Parasites are unique study organisms for evolutionary ecologists. Yet, molecular ecology studies on parasites have lagged far behind those on free-living organisms. The goal of the review in Chapter 2 was to illustrate areas of research that may be of particular interest in relation to the parasitic life style and...
To identify factors limiting 'Candidatus Pelagibacter ubique' maximum cell density and growth rate in pure culture on seawater, the genome sequence of 'Cand. P. ubique' was analyzed, culturing experiments with organic and inorganic nutrient additions were made, and radiotracer uptake experiments were performed. The genome was sequenced, custom data mining...
