Product of the oncogene-activating gene Tpr is a phosphorylated protein of the nuclear pore complex
Department of Cell Biology; Program in Molecular Medicine
Medical Subject Headings
Animals; Antibodies, Monoclonal; Base Sequence; Blotting, Western; DNA, Complementary; Female; Fluorescent Antibody Technique; Humans; Mice; Mice, Inbred BALB C; Molecular Sequence Data; Nuclear Envelope; Nuclear Pore Complex Proteins; Proto-Oncogene Proteins; Tumor Cells, Cultured; Uterine Cervical Neoplasms
Cell Biology | Life Sciences | Medicine and Health Sciences
We have identified a component of the human nuclear pore complex and have shown that it is the product of a gene involved in oncogenic activation. A monoclonal antibody raised against purified nuclear matrix proteins recognizes a single protein with an electrophoretic mobility of approximately 300 kDa and stains the nuclear envelope in a punctate pattern typical of nuclear pores. The antibody was used to screen lambda gt11 human cDNA libraries, and the resulting clones were sequenced and compared to sequences in the Genbank database. An exact match was found with the human tpr (for translocated promoter region) gene, a gene shown previously to be involved in the oncogenic activation of several protein kinases. Double-label immunofluorescent microscopy with the anti-Tpr antibody and an antibody to the previously characterized nuclear pore complex protein nup153 confirms that Tpr is localized to the nuclear pore complex. Tpr is located on the cytoplasmic face of the nucleus, as demonstrated by immunofluorescent staining of cells permeabilized with digitonin. Tpr is a 2,349-amino acid protein with extensive coiled-coil domains and an acidic globular C-terminus. The protein contains 10 leucine zipper motifs and numerous sites for phosphorylation by a variety of protein kinases. Immunoprecipitation of Tpr from 32P-orthophosphate-labeled cells shows that it is a phosphoprotein. Potential functions for Tpr and possible mechanisms for the transforming activity of Tpr fusion proteins are discussed.
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Citation: J Cell Biochem. 1996 Apr;61(1):48-60. Link to article on publisher's site
Journal of cellular biochemistry
Bangs, Peter Lawrence; Sparks, Cynthia A.; Odgren, Paul R.; and Fey, Edward G., "Product of the oncogene-activating gene Tpr is a phosphorylated protein of the nuclear pore complex" (1996). GSBS Student Publications. 76.