a cargo de

prep. in charge of

= charged with, in charge (of), at the helm (of)
Ex: An organization now exists, endowed by Ranganathan, and charged with the maintenance of the scheme now that he himself has died. Ex: The vice-president in charge of marketing services, Una Feaver, is responsible for media planning and buying, research, and sales promotion. Ex: With a new administration at the helm, prospects are good for a coordinated effort within the government to establish viable information management strategies for the 1990s.