Cell Cycle

Kinase Controls Chromatin

Science's STKE  17 Jul 2001:
Vol. 2001, Issue 91, pp. tw2
DOI: 10.1126/stke.2001.91.tw2

The activity of Tousled-like kinases (Tlks) is cell-cycle-regulated in mammalian cells, and although they are highly conserved in yeast and fly, their function is not known. Sillje and Nigg have now identified human substrates that suggest a possible role in regulating chromatin structure. The substrates are homologs of a yeast and fly protein called anti-silencing function 1 (Asf1), which is known to derepress gene silencing and to organize chromatin during DNA repair and replication. The mammalian Asf1 proteins associated with, and were phosphorylated by, Tlks in vitro. Phosphorylation of Asf in mammalian cells also correlated with maximum Tlk activity during the cell division cycle. The authors speculate that Tlks may regulate Asf1 protein interaction with other chromatin assembly factors.

H. H. W. Sillje, E. A. Nigg, Identification of human Asf1 chromatin assembly factors as substrates of Tousled-like kinases. Curr. Biol. 11, 1068-1073 (2001). [Online Journal]