  We have studied phenomenological implications of several family non-universal
U(1)$^\prime$ sub-models in the U(1)$^\prime$-extended Minimal Supersysmmetric
Standard Model (UMSSM) possesing an extra down quark type exotic field. In
doing this, we have started by enforcing anomaly cancellation criteria to
generate a number of solutions in which the extra U(1)$^\prime$ charges of the
particles are treated as free parameters. We have then imposed existing bounds
coming from colliders and astrophysical observations on the assumed sub-models
and observed that current limits dictate certain charge orientations, for
instance, $Q_{H_u}\sim Q_{H_d}$ is preferred in general and the charge of the
singlet $Q_S$ cannot be very small ($|Q_S|>$ 0.4) even if any of the charges is
allowed to take any value within the $[-1, 1]$ range. We have finally studied
the potential impact of such non-universal charges on $Z'$ mediated processes
and made predictions for existing and future experiments. It has turned out
that UMSSMs with or without the presence of light exotic quarks can yield
distinguisable signatures if non-universal charges are realised in the leptonic
sector of such models.
