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Full-Text Articles in Biological Phenomena, Cell Phenomena, and Immunity

Roles And Regulation Of Nf-Κb In Platelet-Derived Growth Factor Transformed Cells, Takeshi Shimamura Dec 2002

Roles And Regulation Of Nf-Κb In Platelet-Derived Growth Factor Transformed Cells, Takeshi Shimamura

Dissertations

Platelet-derived growth factor (PDGF) is overexpressed in various cancer cells and the overexpression may be correlated with the prognosis of several types of cancers. Binding of PDGF to its receptors induces receptor dimerization and subsequent autophosphorylation of tyrosine residues in the receptor’s cytoplasmic domains. The phosphorylated tyrosine residues interact with the secondary signaling molecules to initiate signaling cascades that trigger cellular changes by affecting downstream effectors. In our recent publication, we have shown that a NF-κB mediates the transformation of mouse fibroblast cells overexpressing PDGF B chain. Though there is a significant correlation between PDGF stimulation and NF-κB activity, it …


Regulation Of Retinoic Acid Receptor Α By Protein Kinase C In B16 Mouse Melanoma Cells, Goran Boskovic, Dinakar Desai, Richard M. Niles Jul 2002

Regulation Of Retinoic Acid Receptor Α By Protein Kinase C In B16 Mouse Melanoma Cells, Goran Boskovic, Dinakar Desai, Richard M. Niles

Biochemistry and Microbiology

We have previously found that retinoic acid stimulates the expression of protein kinase Cα (PKC) in B16 mouse melanoma cells. Because it has been reported that PKC can phosphorylate retinoic acid receptor (RAR) and alter its function, we determined whether changes in the level and/or activity of PKC could affect the expression or function of the RAR in B16 melanoma. Using in vivophosphorylation and band shift techniques, we could not demonstrate that altering PKC activity and/or protein level changed thein vivo phosphorylation of RARα. However activation of PKC resulted in increased RARα protein. Increased receptor protein correlated with …


Characterization Of Subcellular Localization And Stability Of A Splice Variant Of G Alpha I2., Philip B Wedegaertner May 2002

Characterization Of Subcellular Localization And Stability Of A Splice Variant Of G Alpha I2., Philip B Wedegaertner

Department of Microbiology and Immunology Faculty Papers

BACKGROUND: Alternative mRNA splicing of alpha(i2), a heterotrimeric G protein alpha subunit, has been shown to produce an additional protein, termed salpha(i2). In the salpha(i2) splice variant, 35 novel amino acids replace the normal C-terminal 24 amino acids of alpha(i2). Whereas alpha(i2) is found predominantly at cellular plasma membranes, salpha(i2) has been localized to intracellular Golgi membranes, and the unique 35 amino acids of salpha(i2) have been suggested to constitute a specific targeting signal. RESULTS: This paper proposes and examines an alternative hypothesis: disruption of the normal C-terminus of alpha(i2) produces an unstable protein that fails to localize to plasma …


Gravistimulation Of Pisum Sativum And Expression Of The Cell Membrane Expansin Proteins, Sherrine A. Ibrahim Jan 2002

Gravistimulation Of Pisum Sativum And Expression Of The Cell Membrane Expansin Proteins, Sherrine A. Ibrahim

Theses, Dissertations and Capstones

This thesis research investigates the regulation of gene expression in pea stems (Pisum sativum) after changes in orientation to gravity (gravistimulation). Specifically, this project examines the changes in extracellular soluble proteins due to gravistimulation in pea seedlings. This change in gravity alters the cellular growth pattern, which can be directly linked to enzymatic activity resulting in the expression of cell wall loosening proteins called expansins. This loosening of the cell wall matrix subsequently increases elasticity in growing cells, thus leading to an upward curvature of the stems. These changes in enzymatic activity and gene expression are crucial for …


Small Glutamine-Rich Protein/Viral Protein U–Binding Protein Is A Novel Cochaperone That Affects Heat Shock Protein 70 Activity, Peter C. Angeletti, Doriann Walker, Antonito T. Panganiban Jan 2002

Small Glutamine-Rich Protein/Viral Protein U–Binding Protein Is A Novel Cochaperone That Affects Heat Shock Protein 70 Activity, Peter C. Angeletti, Doriann Walker, Antonito T. Panganiban

Nebraska Center for Virology: Faculty Publications

Molecular chaperone complexes containing heat shock protein (Hsp) 70 and Hsp90 are regulated by cochaperones, including a subclass of regulators, such as Hsp70 interacting protein (Hip), C-terminus of Hsp70 interacting protein (CHIP), and Hsp70-Hsp90 organizing factor (Hop), that contain tetratricopeptide repeats (TPRs), where Hsp70 refers to Hsp70 and its nearly identical constitutive counterpart, Hsc70, together. These proteins interact with the Hsp70 to regulate adenosine triphosphatase (ATPase) and folding activities or to generate the chaperone complex. Here we provide evidence that small glutamine-rich protein/viral protein U–binding protein (SGT/UBP) is a cochaperone that negatively regulates Hsp70. By “Far-Western” and pull-down assays, SGT/UBP …