The Function of the Golgi Ribbon Structure – An Enduring Mystery Unfolds

The Golgi apparatus in vertebrate cells consists of individual Golgi stacks fused together in a continuous ribbon structure. The ribbon structure per se is not required to mediate the classical functions of this organelle and the relevance of the “ribbon” structure has been a mystery since first identified ultrastructurally in the 1950s. Recent advances recognize a role for the Golgi apparatus in a range of cellular processes, some mediated by signaling networks which are regulated at the Golgi. Here we review the cellular processes and signaling events regulated by the Golgi apparatus and, in particular, explore an emerging theme that the ribbon structure of the Golgi contributes directly to the regulation of these higher order functions. The Golgi apparatus has recently emerged as a signaling hub for co‐ordinating cellular processes. Here we explore the concept that the Golgi ribbon structure is critical in regulating higher order processes. Changes in Golgi ribbon morphology, that is, fragmentation into mini‐stacks, modulate cellular processes, and are associated with diseases including neurodegeneration and cancer.