Phosphorylation and activation of protein kinase CK2 by p34cdc2 are independent events.

Recombinant isolated beta-subunit of protein kinase CK2 is readily phosphorylated by p34cdc2/cyclin B kinase at Ser209 with favourable kinetic constants (Km = 1.7 microM, Vmax = 20 nmol.min-1.mg-1). Two synthetic peptides reproducing the 170-215 and the 206-215 C-terminal fragments of the beta-subunit are also phosphorylated though with tenfold higher Km values (19.5 and 28.0 microM, respectively). In contrast, both the beta-subunit associated with the alpha-subunit to give the heterotetrameric holoenzyme and the native CK2 are not appreciably phosphorylated by p34cdc2. These data suggest that the Ser209 beta-subunit phosphorylation observed in intact cells occurs prior to beta-subunit incorporation into the holoenzyme. The isolated CK2 alpha-subunit is not phosphorylated to any appreciable extent by p34cdc2 kinase. Its catalytic activity is nevertheless increased up to fivefold upon incubation with p34cdc2/cyclin B kinase complex. Such a stimulation of activity is comparable to that induced by the beta-subunit and it is paralleled by a 40% decrease of p34cdc2/cyclin B catalytic activity. Similar to beta-subunit, p34cdc2/cyclin B also protects the alpha-subunit against thermal inactivation. CK2 holoenzyme is also stimulated by p34cdc2/cyclin B, albeit less dramatically than the isolated alpha-subunit. Such an effect is also evident with CK2 holoenzyme reconstituted with a mutated beta-subunit lacking the p34cdc2 phosphorylation site and it is not accompanied by any appreciable phosphorylation of either the beta or the alpha-subunit. These data indicate that in vitro CK2 alpha-subunit interacts with and is activated by p34cdc2/cyclin B kinase by a mechanism that does not imply the phosphorylation of CK2

Pragmatic interoperability in the enterprise -- A research agenda

Eective collaboration among today's enterprises is indispensable. Such collaborative synergy is important to foster the creation of innovative value-added products and services that would have otherwise been dicult to achieve if enterprises work in isolation. However, it is a widely held belief that interoperability problems have been one of the perennial hurdles in achieving such collaboration. This research aims to improve the current state of the art in enterprise interoperability research by zeroing in on the notion of pragmatic interoperability(PI). When enterprise systems collaborate by exchanging information, PI goes beyond the compatibility between the structure and the meaning of shared information, it further ensures that the intended eect of the message exchange is realized. This paper outlines our research agenda to address the analysis, design, development and evaluation of a pragmatically interoperable solution for enterprise collaboration