Paul G Fitzgerald

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PURPOSE The 129 strain of mouse carries a mutation in the gene for CP49 (phakinin), an intermediate filament protein thus far demonstrated only in the lens fiber cell. As such, these mice represent naturally occurring mutants of interest in the study of the lens cytoskeleton. However, this strain of mouse is also widely used as a source of embryonic stem(More)
The cDNA coding for calf filensin, a membrane-associated protein of the lens fiber cells, has been cloned and sequenced. The predicted 755-amino acid-long open reading frame shows primary and secondary structure similarity to intermediate filament (IF) proteins. Filensin can be divided into an NH2-terminal domain (head) of 38 amino acids, a middle domain(More)
PURPOSE To describe a previously uncharacterized structural specialization in the mouse lens fiber cell and to delineate its emergence relative to lens development and fiber cell differentiation. METHODS Lens fixation efficiency was explored using (14)C-formaldehyde and autoradiography. Lens fiber cell architecture was examined by scanning electron(More)
Site-directed spin labeling and electron paramagnetic resonance were used to probe residues 281-304 of human vimentin, a region that has been predicted to be a non-alpha-helical linker and the beginning of coiled-coil domain 2B. Though no direct test of linker structure has ever been made, this region has been hypothesized to be flexible with the(More)
PURPOSE To deduce the function of the lens-specific cytoskeletal structure, the beaded filament, by blocking expression of the fiber cell-specific beaded filament protein CP49. METHODS The first exon of the mouse CP49 gene was deleted by using targeted genomic deletion techniques. Gene deletion was assessed through Southern blot analysis and PCR.(More)
PURPOSE To define the remodeling of lens fiber cell intermediate filaments (IF) that occurs with both development and differentiation. METHODS Prenatal and postnatal mice were probed for the IF proteins phakosin, filensin, and vimentin, using light microscope immunocytochemical methodology. RESULTS The pattern of vimentin accumulation in elongating(More)
PURPOSE To determine the function of the lens fiber cell-specific cytoskeletal protein, filensin, in lens biology. METHODS Targeted genomic deletion was used to delete exon 1 and the transcriptional start site of the filensin gene. Resultant chimeric animals were bred to homozygosity for the mutant allele. These animals were outbred to mice bearing the(More)
A simple means of establishing a differentiating rat lens culture system is presented which exhibits a high degree of both morphologic and biochemical differentiation along lens-specific lines. Morphological differentiation includes cell enlargement, displacement from the cell substratum, and the loss of intracellular organelles. Biochemical differentiation(More)
The visual system of birds includes an efferent projection from a visual area, the isthmo-optic nucleus in the midbrain, back to the retina. Using a combination of anterograde labeling of efferent fibers, reconstruction of dye-filled neurons, NADPH-diaphorase staining, and transmission electron microscopy, we have examined the distribution of efferent(More)
PURPOSE The lens assembles two systems of intermediated filaments-vimentin intermediate filament (IF) and highly divergent, lens-specific beaded filament (BF)-sequentially as epithelial cells differentiate into fiber cells. The goal of this study was to identify linker proteins that integrate the different lens IF into the biology of the lens fiber cells.(More)