Tel2: a common partner of PIK-related kinases and a link between DNA checkpoint and nutritional response?

A recent paper (Hayashi et al. 2007) in this issue of Genes to Cells shows that the fission yeast Schizosaccharomyces pombe Tel2, a homologue of mammalian/worm CLK2/Clk-2/Rad-5, physically interacts with all the phosphoinositide 3-kinase-related kinases (PIKKs) that include Rad3/Tel1 (ATR/ATM homologues), Tor1/Tor2 (TOR kinases) and Tra1/Tra2 (TRRAP homologues), raising the possibility that Tel2 family proteins link various PIKK-related cellular processes by interacting with PIKK family proteins. In this minireview, implications and impact of the findings, and a possibility that PIKKs are functionally related through Tel2, are discussed.