  D-branes have a world-volume U(1) gauge field A whose field strength F = dA
gives rise to a Born-Infeld term in the D-brane action. Supersymmetry and kappa
symmetry transformations of A are traditionally inferred by the requirement
that the Born-Infeld term is consistent with both supersymmetry and kappa
symmetry of the D-brane action. In this paper, we show that integrability of
the assigned supersymmetry transformations leads to a extension of the standard
supersymmetry algebra that includes a fermionic central charge. We construct a
superspace one-form on an enlarged superspace related by a coset construction
to this centrally extended algebra whose supersymmetry and kappa symmetry
transformations are derived, rather than inferred. It is shown that under
pullback, these transformations are of the form expected for the D-brane U(1)
gauge field. We relate these results to manifestly supersymmetric approaches to
construction of D-brane actions.
