Regulation, Targets and Functions of CHK

Src family kinases (SFKs) play pivotal roles in multiple signaling pathways (Yeatman, 2004). SFK activity is inhibited by phosphorylation at its C-terminal tyrosine, by CSK (C-terminal Src kinase) and CHK (CSK-homologous kinase). CHK expression is restricted to normal hematopoietic cells, brain, and colon tissues. Downregulation of CHK in brain and colon tumors contributes to tumorigenicity in these tissues. CHK does not phosphorylate Src efficiently, however, in contrast to CSK, CHK inhibits Src kinase activity allosterically. Although the functions of CHK are still largely unknown, potential substrates of CHK including β-synuclein, α-tubulin, α-spectrin, 14-3-3, and Hsp90 have been identified. CHK is regulated epigenetically via promoter methylation. As the unknown roles of CHK are beginning to be revealed, current knowledge of regulation, molecular targets and functions of CHK is summarized, and important topics for future CHK research are discussed

Poly[(μ4-biphenyl-3,3′-dicarboxyl­ato)bis[μ2-1,1′-(butane-1,4-di­yl)diimidazole](μ2-oxalato)dimanganese(II)]

In the title coordination compound, [Mn2(C14H8O4)(C2O4)(C10H14N4)2]n, the biphenyl-3,3′-dicarboxyl­ate and oxalate anions, both situated on inversion centres, function in a bridging mode, linking the dinuclear MnII atoms into wave-like layers. Each 1,1′-(1,4-butane-1,4-di­yl)diimidazole ligand coordinates to two MnII atoms located in adjacent layers via Mn—N coordination bonds, giving a three-dimensional network. As the methyl­ene groups can bend freely relative to each other due to the C atoms connected via single bonds, the 1,1′-(butane-1,4-di­yl)diimidazole ligand forms an S-shaped conformation, which makes the void in the three-dimensional network distorted