Leucine-rich repeat kinase 2 (LRRK2) is a multidomain protein implicated in Parkinson disease (PD); however, the molecular mechanism and mode of action of this protein remain elusive. cAMP-dependent protein kinase (PKA), along with other kinases, has been suggested to be an upstream kinase regulating LRRK2 function. Using MS, we detected several sites phosphorylated by PKA, including phosphorylation sites within the Ras of complex proteins (ROC) GTPase domain as well as some previously described sites (S910 and S935). We systematically mapped those sites within LRRK2 and investigated their functional consequences. S1444 in the ROC domain was confirmed as a target for PKA phosphorylation using ROC single-domain constructs and through site-directed mutagenesis. Phosphorylation at S1444 is strikingly reduced in the major PD-related LRRK2 mutations R1441C/G/H, which are part of a consensus PKA recognition site (1441RASpS1444). Furthermore, our work establishes S1444 as a PKA-regulated 14-3-3 docking site. Experiments of direct binding to the three 14-3-3 isotypes gamma, theta, and zeta with phosphopeptides encompassing pS910, pS935, or pS1444 demonstrated the highest affinities to phospho-S1444. Strikingly, 14-3-3 binding to phospho-S1444 decreased LRRK2 kinase activity in vitro. Moreover, substitution of S1444 by alanine or by introducing the mutations R1441C/G/H, abrogating PKA phosphorylation and 14-3-3 binding, resulted in increased LRRK2 kinase activity. In conclusion, these data clearly demonstrate that LRRK2 kinase activity is modulated by PKA-mediated binding of 14-3-3 to S1444 and suggest that 14-3-3 interaction with LRRK2 is hampered in R1441C/G/H-mediated PD pathogenesis.

A-Kinase Anchoring Proteins (AKAPs) coordinate complex signaling events by serving as spatiotemporal modulators of cAMP-dependent protein kinase activity in cells. Although AKAPs organize a plethora of diverse pathways, their cellular roles are often elusive due to the dynamic nature of these signaling complexes. AKAPs can interact with the type I or type II PKA holoenzymes by virtue of high-affinity interactions with the R-subunits. As a means to delineate AKAP-mediated PKA signaling in cells, we sought to develop isoform-selective disruptors of AKAP signaling. Here, we report the development of conformationally constrained peptides named RI-STapled Anchoring Disruptors (RI-STADs) that target the docking/dimerization domain of the type 1 regulatory subunit of PKA. These high-affinity peptides are isoform-selective for the RI isoforms, can outcompete binding by the classical AKAP disruptor Ht31, and can selectively displace RIα, but not RIIα, from binding the dual-specific AKAP149 complex. Importantly, these peptides are cell-permeable and disrupt Type I PKA-mediated phosphorylation events in the context of live cells. Hence, RI-STAD peptides are versatile cellular tools to selectively probe anchored type I PKA signaling events.

Public banks in nature financial systens. The paper discusses two theoretical approaches to the role of public banks (PBs): the Shaw-McKinnon model and an alternative Keynesian view. In the former, the PBs still in operation in less developing countries would be near to become fully unnecessary, in view of the advance of their financial development in the last twenty years. In the Keynesian approach this hypothesis is unlikely. Financial markets are viewed as structurally inefficient and "incomplete" for the requirements of the process of economic development. Nevertheless, it is undeniable that economic and financial development will require a definition of new strategies for PBs. The paper is concluded with a brief discussion of this issue.Keywords: economic development; financial development; governmental banks. JEL classification: O16; G28; H81.Como "braços financeiros" de políticas voltadas para o desenvolvimento econômico e social, Banco Públicos (BPs) são instituições idiossincráticas, cujo papel se define, a cada governo e período histórico, pelo que se entende serem as necessidades e limitações desse processo. A despeito da heterogeneidade de formas de operação, ditada por essa condição, um aspecto comum aos BPs é o fato de terem iniciado suas operações em mercados financeiros "incompletos", isto é, marcados pela inexistência ou grave insuficiência de determinados segmentos de operação.A atuação de BPs em mercados financeiros incompletos comporta, no plano teórico, pelo menos, duas interpretações. Na visão dominante a partir dos anos

Protein kinase activity is regulated not only by direct strategies affecting activity but also by spatial and temporal regulatory mechanisms. Kinase signaling pathways are coordinated by scaffolding proteins that orchestrate the assembly of multi-protein complexes. One family of such scaffolding proteins are the A-kinase anchoring proteins (AKAPs). AKAPs share the commonality of binding cAMP-dependent protein kinase (PKA). In addition, they bind further signaling proteins and kinase substrates and tether such multi-protein complexes to subcellular locations. The A-kinase binding (AKB) domain of AKAPs typically contains a conserved helical motif that interacts directly with the dimerization/docking (D/D) domain of the regulatory subunits of PKA. Based on a pull-down proteomics approach, we identified neurochondrin (neurite-outgrowth promoting protein) as a previously unidentified AKAP. Here, we show that neurochondrin interacts directly with PKA through a novel mechanism that involves two distinct binding regions. In addition, we demonstrate that neurochondrin has strong isoform selectivity towards the RIIα subunit of PKA with nanomolar affinity.

ResumoOs anos 2011-14 marcam uma fase de desaceleração da economia brasileira, a despeito da aparente manutenção do modelo de política econômica desenvolvimentista que sustentou o crescimento e enfrentou a crise internacional durante o período 2004-10. Tornou-se dominante, desde então, a interpretação de que esse quadro evidenciava o esgotamento do modelo desenvolvimentista, sobretudo na área fiscal: as mesmas estratégias de expansão do gasto público e de desonerações tributárias que estimularam o crescimento a partir de 2004 não produziam mais este efeito. Este artigo questiona essa interpretação a partir de uma leitura keynesiana da política fiscal do Primeiro Governo Dilma. Concluise que esta foi apenas aparentemente expansionista, colaborando, na prática, para a desaceleração econômica. Não se trata, portanto, de ineficácia da política fiscal, mas sim de sua inadequação ao cenário de incerteza do período 2011-14, que exigia do governo uma postura menos conservadora.Palavras-chave: Política fiscal; Macroeconomia keynesiana; Governo Dilma Rousseff; Gasto público; Crescimento econômico. Abstract Fiscal policy in Dilma Rousseff's first government:orthodoxy and regressionThe years 2011-14 mark a slowing down of the Brazilian economy, despite the apparent maintenance of the developmentalist model that sustained growth and faced the international crisis over the period 2004-10. Since then, the interpretation that this situation showed the breakdown of the developmentalist model, especially in the fiscal area, has become dominant. The same expansion strategies of public spending and tax cuts that stimulated growth since 2004 no longer have leverage effects. This paper questions this widespread interpretation using a Keynesian approach of the fiscal policy during Dilma Rousseff's government . It concludes that it was apparently only expansionary, contributing in practice to the economic downturn. Therefore it is not a case of ineffectiveness but rather unsuitable conservative fiscal policy, unable to face the uncertainties of the 2011-14 period.