p94(fer) and p51(ferT) are two nuclear tyrosine kinases encoded by the FER locus in the mouse. While p94(fer) accumulates in somatic cells, p51(ferT) is found solely in meiotic spermatogenic cells. Ectopic expression of p94(fer) or p51(ferT) in CHO cells, led to tyrosine phosphorylation of cellular 66, 68 and 120 kDa proteins. A 120, 68 and 66 kDa phosphoproteins, coimmunoprecipitated with p94(fer) and p51(ferT) from extracts of transfected CHO cells. Subcellular fractionation analysis indicated that the 66 kDa tyrosine phosphorylated protein colocalizes with p51(ferT) to perinuclear and nuclear fractions in actively growing cells. However, in growth arrested cells, the 66 kDa phosphoprotein was associated mainly with chromatin while its level in the other nuclear compartments was significantly reduced. The 66 kDa phosphoprotein may thus mediate the nuclear function of the FER proteins and link it to cell growth.
|Number of pages||6|
|State||Published - 10 Feb 1997|
Bibliographical noteFunding Information:
We thank U. Caro for running the flow cytometry analysis, T. Pawson for supplying the fer cDNA and the E antiserum, M. Karin for supplying the pHS1 plasmid, N. Sonenberg and F. Lejbkowicz for supplying eIF-4A antibodies, R. Wides for his critical reading of the manuscript and S. Victor and A. Goldreich for typing the manuscript. This work was supported by grants from the United States-Israel Binational Foundation, the Council for Tobacco Research – USA, the Israel Cancer Research Fund and the Israel Academy of Sciences.
- Tyrosine kinase