Generalized uncertainty principles (GUP) and, independently, Lorentz symmetry violations are two common features in many candidate theories of quantum gravity. Despite that, the overlap between both has received limited attention so far. In this brief paper, we carry out further investigations on this topic. At the nonrelativistic level and in the realm of commutative spacetime coordinates, a large class of both isotropic and anisotropic GUP models is shown to produce signals experimentally indistinguishable from those predicted by the Standard Model Extension (SME), the common framework for studying Lorentz-violating phenomena beyond the Standard Model. This identification is used to constrain GUP models using current limits on SME coefficients. In particular, bounds on isotropic GUP models are improved by a factor of $10^7$ compared to current spectroscopic bounds and anisotropic models are constrained for the first time.