  We calculate the scalar potential in the gauged N=2 supergravity with a
single hypermultiplet, whose generic quaternionic moduli space metric has an
abelian isometry. This isometry is gauged by the use of a graviphoton gauge
field. The hypermultiplet metric and the scalar potential are both governed by
the single real potential that is a solution to the 3d (integrable) continuous
Toda equation. An explicit solution, controlled by the Eisenstein series
E_{3/2}, is found in the case of the D-instanton-corrected universal
hypermultilet moduli space metric having an U(1)xU(1) isometry, with one of the
isometries being gauged.
