1,721,420 research outputs found
Phosphorylation of protamines by protein kinase C: involvement of sites which are phosphorylated in vivo and are not affected by cAMP-dependent protein kinase.
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Addiction to protein kinase CK2: A common denominator of diverse cancer cells?
No full textAt variance with most oncogenic protein kinases whose malignancy is generally due to genetic alterations conferring constitutive activity, CK2 is a highly pleiotropic Ser/Thr protein kinase naturally endowed with constitutive activity and lacking gain-of-function mutants. Nonetheless CK2 is abnormally elevated in a wide variety of tumors and there is strong evidence that it operates as a cancer driver by creating a cellular environment favorable to neoplasia: notably, CK2 plays a global role as an anti-apoptotic and pro-survival agent, it enhances the multi-drug resistance (MDR) phenotype, it assists the chaperone machinery which protects the "onco-kinome" and it promotes neo-angiogenesis. Based on this scenario we propose that the implication of CK2 in neoplasia is an example of "non oncogene addiction", i.e. over reliance of the perturbed cellular signaling network on high CK2 level for its own maintenance. Consistent with this, an ample spectrum of diverse types of cancer cells have been already shown to rely on high CK2 level for their survival, as judged from their response to specific CK2 inhibitors and silencing of endogenous CK2 catalytic subunits. Remarkably, among these are cells whose cancer phenotype arises from the genetic alteration of oncokinases (e.g. Abl and Alk) different from CK2 and insensitive to the CK2 inhibitors used in those experiments. Based on these premises, CK2 could represent a "multi-purpose" target for the treatment of different kinds of tumors
Identification of pseudo 'phosphothreonyl-specific' protein phosphatase T with a fraction of polycation-stimulated protein phosphatase 2A.
No full textProtein kinase CK2 as a druggable target
No full textCK2 is probably the most pleiotropic Ser/Thr protein kinase with hundreds of endogenous substrates already known, which are implicated in a variety of cellular functions. At variance with most protein kinases whose activity is turned on only in response to specific stimuli, and whose genetic alterations often underlie pathological situations, CK2 is not susceptible to tight regulation and there are no mutations known to affect its constitutive activity. Nevertheless an abnormally high level of CK2 is invariably found in tumours, and solid arguments have accumulated suggesting that CK2 plays a global pro-survival function, which under special circumstances creates a cellular environment particularly favourable to the development and potentiation of the tumour phenotype. Therefore any strategy aimed at attenuating CK2 activity may represent a "master key" for the treatment of different neoplastic diseases. Waiting for the clarification of the epigenetic mechanisms promoting the rise of CK2 in cells predisposed to develop a tumour phenotype, a useful pharmacological aid can come from the improvement of a number of fairly potent and selective CK2 inhibitors already available
Characterization of four tyrosine protein kinases from the particulate fraction of rat spleen.
No full textSubunit structure and autophosphorylation mechanism of casein kinase-TS (type-2) from rat liver cytosol.
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