  Considering shock-accelerated protons in addition to electrons in a
synchrotron radio jet naturally produces the observed X- through gamma ray
continuum emission of flat-spectrum radio-loud AGN, whereas the corresponding
shock-accelerated electrons produce the infrared through optical continuum. All
of these emission components are rapidly variable on short time scales which
can be accounted for by a common origin of the blazar emission in a
relativistic sub-parsec scale jet. Moreover, neutrino fluxes are estimated
which may be observable with the HiRes experiment and the impact on the ISM of
the host galaxy of neutrons escaping from the nuclear jet is investigated.
