A q-deformed free scalar relativistic particle is discussed in the
framework of the BRST formalism. The q-deformed local gauge symmetry and
reparametrization invariance of the first-order Lagrangian have been exploited
for the BRST quantization of this system on a GLq(2) invariant quantum
world-line. The on-shell equivalence of these BRST charges requires the
deformation parameter to be ±1 under certain identifications.The same
restriction (q=±1) emerges from the conservation of the q-deformed
BRST charge on an arbitrary (unconstrained) manifold and the validity of the
BRST algebra. The solutions for the equations of motion respect GLq(2)
invariance on the mass-shell at any arbitrary value of the evolution parameter
characterizing the quantum world-line.Comment: LATEX, 12 page