The dynamical coupled-channels model developed by
Juelich-Georgia group is presented, which presently includes the
gamma-N, pi-N, eta-N and Sigma-K stable channels as well as the
effective pi-pi-N channels pi-Delta, rho-N and sigma-N. Recent progress
on the description of pi-N --> Sigma-K and pion photoproduction within
this model is discussed, with the emphasis given on the gauge invariance
of the photoproduction amplitudes.