Cell Signaling

Keeping Kinases on Target

See allHide authors and affiliations

Science  01 Jul 2011:
Vol. 333, Issue 6038, pp. 14-15
DOI: 10.1126/science.333.6038.14-d

Modification of proteins by protein kinase—mediated covalent phosphorylation regulates almost every biological process in the cell and especially those related to cell division. But with more than 500 kinases in a human cell phosphorylating tens of thousands of proteins, some at multiple sites, how is order maintained? One explanation is that kinases show specificity toward particular sequences in their substrates. Alexander et al. and Kettenbach et al. explored such specificity of five kinases with key roles in controlling cell division. Their phosphoproteomic and peptide screening approaches helped to define the preferred sequences of substrates for these kinases and identified previously unrecognized substrates. Furthermore, Alexander et al. showed that there are also some sequence elements that selectively prevent phosphorylation of a particular substrate by certain kinases. Alexander et al. further proposed that subcellular localization also contributes to specificity, so that kinases that have overlapping preferred motifs are kept spatially separated.

Sci. Sig. 4, rs5; ra42 (2011).

Navigate This Article