Proteasome inhibitor induced gene expression profiles reveal overexpression of transcriptional regulators ATF3, GADD153 and MAD1.

The ubiquitin/proteasome pathway has been implicated in a wide variety of cellular processes and the number of substrates degraded by the proteasome is impressive. Most prominently, the stability of a large number of transcription factors is regulated by ubiquitination. To elucidate pathways regulated by the proteasome, gene expression profiles were generated, comparing changes of mRNA expression of 7900 genes from the UniGene collection upon exposure of cells to the proteasome inhibitors Lactacystin, Lactacystin-beta-lactone or MG132 by means of microarray based cDNA hybridization.

Glyceraldehyde-3-phosphate dehydrogenase, the putative target of the antiapoptotic compounds CGP 3466 and R-(-)-deprenyl.

R-(-)-Deprenyl (Selegiline) represents one of the drugs currently used for the treatment of Parkinson's disease. This compound was shown to protect neurons or glias from programmed cell death in a variety of models. The mechanism of action of neuroprotection as well as inhibition of apoptosis remains elusive.