Scrawny Protease and Cell Differentiation

A new link between the protease activity of an enzyme called scrawny (scny), chromatin modification and cell differentiation, has been described in Science Magazine. Scientists from Howard Hugh Medical Institute Research Laboratories used drosophila (fruit flies) to study a type of histone modification called ubiquitylation. Histones are proteins around which chromosomes coil, comprising part of the system for controlling which genes are expressed and which ones aren't.

Ubiquitin is a very widespread eukaryotic protein, found in so many cell processes that, after its discovery, it was named after the word "ubiquitous". Protein degradation, cell signalling and membrane trafficking are among its many roles in cellular processes, in addition to its role in controlling transcription. In their research on gene expression, Buszczak et al. (2009) found that scny silenced gene expression by deubiquitinylating histone H2B.

In different types of pluripotent stem cells, chromatin modifications are usually under the control of different enzymes, but the enzyme scny was found to play a major role in repressing expression of genes that begin the process of cell differentiation in three different types of stem cells.

_Source:

Buszczak et al. 2009. Drosophila stem cells share a common requirement for the histone H2B ubiquitin protease scrawny. Science 323(5911):248-251. doi:10.1126/science.1165678.