Week In Science

The Salk Institute posted an article, 'When the going gets tough, stress response genes can make do with less,' which has implications for cancer breakthoughs. The discussed discovery relates to a cellular process known as transcription. Gene expression involves transcribing genetic information contained in DNA to a messenger RNA or mRNA for short.

The transcription mechanism is familiar. It is also known to shut down under stressful conditions and damaged DNA can lead to this condition. There are genes that enable a response to damaged DNA. P53 is one of these genes. While it makes sense to shut down cellular processes due to damaged DNA, it would be self-defeating if the same shut down mechanisms also affected genes like p53. Genes having repair functions need to be ready.

The p53 transcription factor, a protein encoded by the p53 gene, can be transcribed when the transcription of proteins has been shut down. P53 in turn is able to initiate the transcription of other genes. RNA polymerase which is needed for transcription is similarly enabled to function. The question is how?

Prior to initiating transcription RNA polymerase is phosphorylated. RNA polymerase also functions together with proteins known as elongation factors. Scientists have discovered that function of RNA polymerase is possible through a process that bypasses these usual mechanisms. This understanding can be a prelude to new techniques designed to fight cancer.