Transforming growth factor-beta (TGF-beta) inhibits pancreatic acinar cell growth. In many cell types, TGF-beta mediates its growth inhibitory effects by activation of Smad proteins. Recently, it has been reported that Smad proteins may interact with the mitogen-activated protein (MAP) kinase signaling pathways. In this study, we report on the interactions between the TGF-beta and MAP kinase si...

We investigate the dynamical behaviour of a holomorphic map f : U → C , where U is an open polynomially convex subset of C, on an f−invariant subset E of U. We also prove a Birkhoff type Theorem for holomorphic maps in several complex variables, i.e. given an injective holomorphic map f, defined in a neighborhood of U, with U star-shaped and f(U) a Runge domain, we prove the existence of a forw...

Mitogen-activated protein (MAP) kinases are members of a 40-45-kDa family of serine/threonine protein kinases that phosphorylate several substrates including microtubule-associated protein-2, S6 kinase, and myelin basic protein. Activity of MAP kinases is regulated by growth factors that stimulate the phosphorylation of threonine 188 and tyrosine 190 in the kinase. In this paper direct evidence...

In Xenopus oocytes, mitogen-activated protein (MAP) kinase can be activated by progesterone treatment or by microinjection of cyclin A, both of which lead to activation of the cdc2 protein kinase. The tyrosine kinase pp60v-src has previously been shown to accelerate progesterone-induced oocyte maturation and to increase the phosphorylation of ribosomal protein S6 by pp90rsk, most likely by acti...

M itogen-activated protein (MAP) kinase cascades are a standard player in the signal transduction literature for diverse organisms (1–3). Previous work has shown that specific MAP kinases become activated during plant responses to pathogens, suggesting a role for MAP kinase cascades in disease resistance. However, no function-blocking experiments had demonstrated a causal role until the work of...

In B16 melanoma cells, mitogen-activated protein (MAP) kinases are activated during cAMP-induced melanogenesis (Englaro, W., Rezzonico, R., Durand-Clément, M., Lallemand, D., Ortonne, J. P., and Ballotti, R. (1995) J. Biol. Chem. 270, 24315-24320). To establish the role of the MAP kinases in melanogenesis, we studied the effects of a specific MAP kinase kinase (MEK) inhibitor PD 98059 on differ...