CK2 is a protein serine/threonine kinase which is a highly conserved and ubiquitous protein kinase. It is localized in the cytoplasmic and nuclear compartments, which accords with its multiple functional activities in the cell. Pertinent to this is also the recognition that a large number of putative substrates for this kinase have been identified in various compartments of the cell. New evidence from several laboratories has further reinforced the involvement of CK2 in signal transduction related to many cellular functions, thus underscoring the significance of its functional role in normal and abnormal cell growth and proliferation.

This volume provides an overview of the state of knowledge concerning this intriguing protein kinase. It brings together contributions from leading investigators engaged in research in this field. Key developments during the past three years pertain to the elaboration of the crystal structure and definition of novel functions of the kinase, such as its role as an inhibitor of apoptosis. Additionally, the shuttling of the kinase to various compartments in response to physiological and stress stimuli appears to be a key feature of the functional regulation of its activity in the cell.

Inhalt
Characterization of CK2 holoenzyme variants with regard to crystallization.- Generation of mutants of CK2? which are dependent on the ?-subunit for catalytic activity.- Functional specialization of CK2 isoforms and characterization of isoform-specific binding partners.- A surface plasmon resonance study of the interactions between the component subunits of protein kinase CK2 and two protein substrates, casein and calmodulin.- The activity of CK2 in the extracts of COS-7 cells transfected with wild type and mutant subunits of protein kinase CK2.- Transcriptional coordination of the genes encoding catalytic (CK2?) and regulatory (CK2?) subunits of human protein kinase CK2.- Genes targeted by protein kinase CK2: A genome-wide expression array analysis in yeast.- Consequences of CK2 signaling to the nuclear matrix.- Localization of individual subunits of protein kinase CK2 to the endoplasmic reticulum and to the Golgi apparatus.- Visualization and molecular analysis of nuclear import of protein kinase CK2 subunits in living cells.- Identification and characterization of proteins that interact with Drosophila melanogaster protein kinase CK2.- A gene located at 72A in Drosophila melanogaster encodes a novel zinc-finger protein that interacts with protein kinase CK2.- Environmental reprogramming of the expression of protein kinase CK2? subunit in fish.- Mutation at the CK2 phosphorylation site on Cdc28 affects kinase activity and cell size in Saccharomyces cerevisiae.- Distinctive features of plant protein kinase CK2.- Cloning and characterization of the cDNA coding for the catalytic ? subunit of CK2 from tobacco.- Regulation of the human papillomavirus oncoproteins by differential phosphorylation.- HIV-1 Rev transactivator: A ?-subunit directed substrate and effectorof protein kinase CK2.- Protein kinase CK2: Signaling and tumorigenesis in the mammary gland.- Response of cancer cells to molecular interruption of the CK2 signal.- The genomic structure of two protein kinase CK2? genes of Xenopus laevis and features of the putative promoter region.- Index to Volume 227.