  Many transport processes in nature take place on substrates, often considered
as unidimensional lanes. These unidimensional substrates are typically
non-static: affected by a fluctuating environment, they can undergo
conformational changes. This is particularly true in biological cells, where
the state of the substrate is often coupled to the active motion of
macromolecular complexes, such as motor proteins on microtubules or ribosomes
on mRNAs, causing new interesting phenomena. Inspired by biological processes
such as protein synthesis by ribosomes and motor protein transport, we
introduce the concept of localized dynamical sites coupled to a driven lattice
gas dynamics. We investigate the phenomenology of transport in the presence of
dynamical defects and find a novel regime characterized by an intermittent
current and subject to severe finite-size effects. Our results demonstrate the
impact of the regulatory role of the dynamical defects in transport, not only
in biology but also in more general contexts.

Statistical Mechanics;Subcellular Processes