Role-Based Access Control models (RBACs) — and their extensions — are currently considered the most effective approach for engineering access control in complex information systems and dynamic organisations. In this paper we consider their application in the context of Multi-Agent Systems (MAS) — in particular for models and infrastructures supporting role-based organisation models — by means of the notion of Agent Coordination Context (ACC). Here the ACC is used as organisation abstraction released by the MAS infrastructure, defining the runtime context of an agent in terms of its actions/perceptions, according to the roles it is playing inside an organisation. In the paper, we discuss how the ACC abstraction has been used in TuCSoN coordination infrastructure to implement an RBAC-like model, making it possible to dynamically specify and enact articulated role policies, including also interaction protocols.