Biochemical analysis of retinoblastoma related factor complexes in Drosophila melanogaster

• Applicant: Professor Dr. Alexander Brehm
• Subject Area: Cell Biology
• Term: from 2002 to 2009
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 5355655

The Retinoblastoma tumour suppressor protein plays a fundamental role in cell cycle control and cancer. Recently, it has become apparent that pRb functions within multisubunit complexes to repress transcription and replication. Some of these complexes enzymatically alter local chromatin structure by histone modification or ATP-dependent chromatin remodelling. The composition and precise mechanism of action of pRb complexes is currently unknown. A thorough biochemical analysis of pRb function is hampered by the pRb inactivation encountered in many of the (transformed) cell lines typically used for purification of mammalian protein complexes. Drosophila embryos have proven to be ideally suited for the purification and analysis of protein complexes from wild-type cells. Drosophila contains two pRb homologues. Genetic analysis has demonstrated that fundamental aspects of the pRb pathway are conserved in the fly. However, the fly retinoblastoma proteins and complexes have not been studied. I propose to investigate the biochemistry of the Drosophila retinoblastoma like factor, RBF. RBF protein complexes will be purified from wild-type Drosophila embryo extracts and analysed for their subunit composition and enzymatic activities. The proposed project is the first instance of a biochemical analysis of tumour suppressor protein complexes isolated from non-transformed cells.

• DFG Programme: Research Grants