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No description available.

Abstract not available

Abstract not available

It has been recently demonstrated that the cytokine interleukin (IL)-6 is unique among the so called

Thesis (Ph.D.)--University of Toledo, 2006. / "In partial fulfillment of the requirements for the degree of Doctor of Philosophy in Biomedical Sciences." Major advisor: Zi-Jian Xie. Includes abstract. Title from title page of PDF document. Bibliography: pages 64-70, 104-108, 121-158.

Thesis (M. Phil.)--University of Hong Kong, 2006. / Title proper from title frame. Also available in printed format.

Thesis (Ph. D.)--University of Hong Kong, 2006. / Title proper from title frame. Also available in printed format.

Tn5 mutagenesis of apdA (for antibiotic production) and deletion of gacA (for global antibiotic and cyanide) resulted in the same pleiotropic phenotype in Pseudomonas fluorescens (i.e. production of an array of secondary metabolites including the antibiotics pyrrolnitrin, pyoluteorin, and 2,4-diacetylphloroglucinol as well as a tryptophan-side-chain oxidase, hydrogen cyanide, and an extracellular protease was abolished). The apdA and gacA loci were identified and cloned from the genome of Pf-5. Nucleotide sequencing of the apdA and gacA loci was used to identify the open reading frames for these genes. The deduced amino acid sequences for apdA and gacA exhibited similarity to sensor kinase (ApdA) and response regulator (GacA) proteins that comprise two-component regulatory systems. The C-terminal domain of GacA containing the putative helix-turn-helix DNA-binding motif was fused to the glutathione S-transferase protein. The glutathione S-transferase GacA C-terminal fusion protein was used in a cycle selection procedure that was designed to identify GacA binding sites from a complex pool of DNA fragments. Although a putative binding site for GacA was identified using the cycle selection procedure, the results were inconclusive due to several inconsistencies in the DNA-binding assay. The upstream region of one gene, which codes for a putative porin, was identified as a putative binding site for GacA by the cycle selection procedure. Studies initiated to determine whether gacA regulates transcription of this putative porin gene have been unsuccessful, so it remains unclear whether this gene is regulated by GacA. Also, asymptotic limits to biological control of Rhizoctonia damping-off of cotton were observed with the biological control agent P. fluorescens Pf-5. / Graduation date: 1999

The thesis begins with an introduction to signal transduction and an analysis of current understanding of plant signal transduction. There are similarities between plants and animals, but also key differences, including lack of protein kinase C and of a cAMP signaling pathway in plants, and presence in plants of calcium dependent protein kinase (CDPK), which has a kinase catalytic domain contiguous with a C-terminal calmodulin-like domain. The next section examines protein kinase activity in the plasma membrane (PM) of zucchini hypocotyls. Zucchini PM contains four or more polypeptides with calcium-requiring protein kinase activity. The enzymes appear to be tightly associated with the PM, and at least three are recognized by monoclonal antibody to soybean soluble CDPK. Total proteins from several different organs of zucchini seedlings contain kinases with molecular weights similar to the hypocotyl PM enzymes. In the third section details of partial purification of the solubilized PM kinases are presented. Kinases which do not crossreact with anti-CDPK monoclonal antibody were resolved by anion exchange from ones which do crossreact. Peptide mapping was used to test the relationship between the kinases. Results of peptide mapping suggest that at least three types of protein kinase are present in zucchini PM, two of which are immunologically similar to CDPK and one of which is not. The last section concerns the potential for testing interactions between PM protein kinases and plasma membrane auxin binding proteins (ABP's) by use of photoaffinity labeling of ABP's. Causes of variable photoaffinity labeling by an azido-IAA are considered. Labeling of both the tomato mutant diageotropica and the parent VFN membranes was inexplicably inconsistent. / Graduation date: 1994