We consider dimensionally reduced versions of N=2 four- dimensional supersymmetric Yang-Mills theory and determine the one-loop effective Lagrangians associated with the motion over the corresponding moduli spaces. In the (0+1) case, the effective Lagrangian describes an N=4 supersymmetric quantum mechanics of the Diaconescu--Entin type. In (1+1) dimensions, the effective Lagrangian represents a twisted N=4 supesymmetric sigma model due to Gates, Hull, and Rocek. We discuss the genetic relationship between these two models and present the explicit results for all gauge groups.