Control of cell proliferation by Polycomb group proteins (PcG) is an important facet of cellular homeostasis and its disruption can promote tumorigenesis. CBX7 is a novel PcG protein which is found to control the growth of normal cells. CBX7 is a gene that encodes a Polycomb protein, as shown by sequence homology, its interaction with Ring1 and its localization to nuclear Polycomb bodies. CBX7 extends the lifespan of a wide range of normal human cells and immortalizes mouse fibroblasts by downregulating expression of the Ink4a/Arf locus. CBX7 does not inter-function or colocalize with Bmi1, and both can exert their actions independently of each other as shown by reverse genetics. CBX7 was highly expressed in three different prostate cancer cell lines and present at elevated levels in normal prostate. (Gil et al., 2004).
Immunohistochemistry (Formalin/PFA-fixed paraffin-embedded sections) analysis of human lung carcinoma tissue labelling cbx7 with ab91431 at 1/200 (1µg/ml). Detection: DAB.
Western blot - cbx7 antibody (ab91431)
All lanes : Anti-cbx7 antibody (ab91431) at 0.04 µg/ml
Lane 1 : HeLa whole cell lysate at 50 µg Lane 2 : HeLa whole cell lysate at 15 µg Lane 3 : HeLa whole cell lysate at 5 µg Lane 4 : 293T whole cell lysate at 50 µg
Developed using the ECL technique
Predicted band size : 28 kDa
Exposure time : 10 seconds
Immunoprecipitation - cbx7 antibody (ab91431)
cbx7 was immunoprecipitated from HeLa whole cell lysate, using ab91431 at 10 µg/mg of lysate. 20% of the immunoprecipitae was loaded per lane for the subsequent Western blot and probed with ab91431 at 1 µg/ml (lane 1) or a control IgG (lane 2). Detetion: chemoluminescence with exposure time of 30 seconds.