BRS1, a serine carboxypeptidase, regulates BRI1 signaling in Arabidopsis thaliana

Brassinosteroid-insensitive 1 (BRI1) of Arabidopsis thaliana encodes a cell surface receptor for brassinosteroids. Mutations in BRI1 severely affect plant growth and development. Activation tagging of a weak bri1 allele (bri1-5) resulted in the identification of a new locus, brs1-1D. BRS1 is predicted to encode a secreted carboxypeptidase. Whereas a brs1 loss-of-function allele has no obvious mutant phenotype, overexpression of BRS1 can suppress bri1 extracellular domain mutants. Genetic analyses showed that brassinosteroids and a functional BRI1 protein kinase domain are required for suppression. In addition, overexpressed BRS1 missense mutants, predicted to abolish BRS1 protease activity, failed to suppress bri1-5. Finally, the effects of BRS1 are selective: overexpression in either wild-type or two other receptor kinase mutants resulted in no phenotypic alterations. These results strongly suggest that BRS1 processes a protein involved in an early event in the BRI1 signaling.

Kitab al-amthal =: seu proverbiorum Arabicorum centuriæ duæ : ab anonymo quodam Arabe collectæ & explicatæ

cum interpretatione Latina & scholiis Iosephi Scaligeri et Thomæ Erpenii.

A New Start for the EU’s Area of Freedom, Security and Justice? Setting of Priorities for the New European Commission. CEPS Commentary, 23 September 2014

The nomination of a First Vice-President (Frans Timmermans) in charge of rule of law and the EU Charter of Fundamental is one of the more far-reaching innovations contained in the new institutional shape of the Juncker Commission. This CEPS Commentary by Sergio Carrera and Elspeth Guild welcomes the fact that a new fundamental rights and rule of law First Vice-President will exercise a coordination and advisory role over the other two JHA Commissioners – Věra Jourová, responsible for Justice, Consumers and Gender Equality (DG Justice); and Dimitris Avramopoulos, responsible for Migration and Home Affairs (DG Home Affairs), but expresses a note caution whether this new role and triangular relationship can be made to work effectively in practice.

What can the Better Regulation Commissioner do for the EU? CEPS Commentary, 29 September 2014

This commentary welcomes the creation and prominence given by President Juncker to the new post of First Vice-President in charge of Better Regulation, Inter-Institutional Relations, the Rule of Law and the Charter of Fundamental Rights as among the most interesting of several novelties contained in the proposed Commission and overdue. After all, as the authors point out, better regulation has been underpinning the Commission’s core business, namely, EU regulation, for over a decade. At the same time, however, they warn that Commissioner-designate Frans Timmermans is receiving an extremely challenging mandate which pose many difficulties to overcome.