M-phase entry in eukaryotic cells is driven by activation of MPF, a regulatory factor composed of cyclin B and the protein kinase p34(cdc2). In G2-arrested Xenopus oocytes, there is a stock of p34(cdc2)/cyclin B complexes (pre-MPF) which is maintained in an inactive state by p34(cdc2) phosphorylation on Thr14 and Tyr15. This suggests an important role for the p34(cdc2) inhibitory kinase(s) such...

RSK [for 90 kDa ribosomal S6 kinase (p90rsk); also known as MAPKAP-K1] and MSK (for mitogenand stressactivated protein kinase) constitute a family of protein kinases that mediate signal transduction downstream of MAP kinase cascades. RSK is activated by MAP kinases of the extracellular signalregulated kinase (ERK) family in response to growth factors, many polypeptide hormones, neurotransmitter...

A series of new, covalent polyethylene glycol (PEG)-streptokinase adducts were synthesized and characterized. PEGs with average molecular weights of 2,000, 4,000, and 5,000 were activated with carbonyldiimidazole and coupled to the protein under standardized reaction conditions. Steady-state kinetic analysis demonstrated comparable Km values for the activation of plasminogen by streptokinase, P...

We previously reported that extra-slow-growing Bradyrhizobium japonicum isolates obtained from three field sites in Japan, designated as HRS (highly reiterated sequence-possessing) strains, have high copy numbers of the insertion sequences RSK and RSL. When strain collections in the USA, Japan, Korea, Thailand and China were examined by Southern hybridization using RSK, RSL and IS1631 as probes...

Open reading frame 45 (ORF45) of Kaposi sarcoma-associated herpesvirus (KSHV) causes sustained activation of p90 ribosomal S6 kinase (RSK), which is crucial for KSHV lytic replication, but the exact functional roles remain to be determined. To characterize the biological consequence of persistent RSK activation by ORF45, we screened known cellular substrates of RSK. We found that ORF45 induced ...

Background. Staphylokinase (STA), a protein with known profibrinolytic properties, is produced by transduced Staphylococcus aureus strains. In experimental animal models, recombinant staphylokinase (STAR) is less immunogenic and more active toward platelet-rich arterial blood clots than streptokinase. Methods and Results. In the present study, 10 mg STAR given intravenously over 30 minutes was ...

In this paper, we investigate the super RSK correspondence, first introduced by Pak and Postnikov (1994), which generalizes both the RSK correspondence and the dual RSK correspondence. The bijection relates objects that are known as oscillating supertableau and (intransitive) supergraphs. We prove a number of theorems that were stated in the original paper of Pak and Postnikov, but whose proofs...

The clinical availability of small molecule inhibitors specifically targeting mutated BRAF marked a significant breakthrough in melanoma therapy. Despite a dramatic anti-tumour activity and improved patient survival, rapidly emerging resistance, however, greatly limits the clinical benefit. The majority of the already described resistance mechanisms involve a reactivation of the MAPK signalling...

The ataxia telangiectasia mutated- and rad3-related kinase (ATR)/Chk1 pathway is a sentinel of cell cycle progression. On the other hand, the Ras/mitogen-activated protein kinase/90-kDa ribosomal S6 kinase (p90 RSK) pathway is a central node in cell signaling downstream of growth factors. These pathways are closely correlated in cell proliferation, but their interaction is largely unknown. Here...