Mechanism of regulation of Raf-1 by Ca2+/Calmodulin-dependent kinase II

Salzano, Marcella (2011) Mechanism of regulation of Raf-1 by Ca2+/Calmodulin-dependent kinase II. [Tesi di dottorato] (Inedito)

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Abstract

The calcium-calmodulin dependent kinase II (CaMKII) is an ubiquitous serine/threonine protein kinase involved in multiple signalings and biological functions. It has been demonstrated that in epithelial and mesenchimal cells CaMKII participates with Ras to Raf-1 activation and that it is necessary for ERK activation by diverse factors. Raf-1 activation is complex. Maximal Raf-1 activation is reached by phosphorylation at Y341 by Src and at S338. Although early data proposed the involvement of p21-activated kinase 3 (Pak3), the kinase phosphorylating S338 is not definitively identified. Aim of my thesis is to go more insight into the molecular mechanisms of CaMKII/Raf-1 interaction and to verify the hypothesis that CaMKII phosphorylates Raf-1 at Ser338. To this purpose, I investigated the role of CaMKII in Raf-1 and ERK activation by oncogenic Ras and other factors, in COS-7 and NIH3T3 cells. Serum, SrcY527 and RasV12 activated CaMKII. CaMKII was necessary for Raf-1 and ERK activation by all these factors. CaMKII was necessary to the phosphorylation of S338 Raf-1 by serum, fibronectin or oncogenic Ras. Conversely, the inhibition of phosphatidylinositol 3-kinase, which in turn activates Pak3, was ineffective. The direct kinase activity of CaMKII on the serine 338 residue, was demonstrated in vitro by interaction of purified kinases. These results demonstrate that CaMKII phosphorylates Raf-1 at S338 and partecipates to ERK activation upon different physiologic and pathologic stimuli in the MAPK cascade. This kinase, might have a role in cancers harbouring oncogenic Ras and could represent a new therapeutic target for pharmacological intervention in these tumors.

Tipologia di documento:Tesi di dottorato
Parole chiave:CaMKII; Raf-1; oncogenic Ras
Settori scientifico-disciplinari MIUR:Area 06 Scienze mediche > MED/04 PATOLOGIA GENERALE
Coordinatori della Scuola di dottorato:
Coordinatore del Corso di dottoratoe-mail (se nota)
Avvedimento, Vittorio Enricoavvedim@unina.it
Tutor della Scuola di dottorato:
Tutor del Corso di dottoratoe-mail (se nota)
Vitale, Mariomavitale@unisa.it
Stato del full text:Accessibile
Data:29 Novembre 2011
Numero di pagine:51
Istituzione:Università di Napoli Federico II
Dipartimento o Struttura:Biologia e patologia cellullare e molecolare "L. Califano"
Stato dell'Eprint:Inedito
Scuola di dottorato:Medicina molecolare
Denominazione del dottorato:Patologia e fisiopatologia molecolare
Ciclo di dottorato:24
Numero di sistema:8666
Depositato il:13 Dicembre 2011 12:32
Ultima modifica:23 Aprile 2012 11:25

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