Editorial

Abstract

Since the first publication 10 years ago, the endosomal sorting complex required for transport (ESCRT) field has produced close to 500 research papers and reviews. This impressive number reflects the breadth of cellular functions that are dependent on the ESCRT proteins and the consequent increase in the number of scientists who joined this research field. Unlike many other research topics that, over time, become more and more focused on mechanistic details, the ESCRT field is still expanding and now includes cellular pathways that are not obviously connected to the protein trafficking and membrane-deforming activities originally ascribed to the ESCRTs. These ESCRT-dependent cellular functions include localization of RNA molecules and regulation of spindle pole replication. The diversity of ESCRT functions might be a consequence of the evolutionary age of these proteins, spanning more than two billion years of biological evolution. Furthermore, the ESCRT field has become a prime example of modern cell biology research by employing multidisciplinary approaches to study a complex system. Protein trafficking has joined with biochemistry, structural biology, biophysics and mathematics to gain insight into the ESCRT machinery itself and its interaction with membranes and other proteins. Together, these characteristics of the ESCRT field make this research topic on the one hand very exciting and worth discussing but on the other hand very difficult to review. Therefore, the reviews in this issue of Traffic will not attempt to cover all that is known about the ESCRTs. Instead the five reviews highlight some of the recent findings and point out interesting new developments in the field. These include new insights into ESCRT-mediated cytokinesis, regulation of ESCRTs by cell physiology, involvement of ESCRTs in cell signaling, protein interaction motifs within the ESCRT machinery and the role of ubiquitin in ESCRT function. Markus Babst 1