The Cell Biology of the Endocytic System from an Evolutionary Perspective (original) (raw)

  1. Ka Fai Leung3,
  2. Mark C. Field3 and
  3. Joel B. Dacks1
  4. 1Department of Cell Biology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta T6G 2H7, Canada
  5. 2Department of Science, Augustana Faculty, University of Alberta, Camrose, Alberta T4V 2R3, Canada
  6. 3Division of Biological Chemistry and Drug Discovery, University of Dundee, Dundee, Scotland DD1 5EH, United Kingdom
  7. Correspondence: dacks{at}ualberta.ca

Abstract

Evolutionary cell biology can afford an interdisciplinary comparative view that gives insights into both the functioning of modern cells and the origins of cellular systems, including the endocytic organelles. Here, we explore several recent evolutionary cell biology studies, highlighting investigations into the origin and diversity of endocytic systems in eukaryotes. Beginning with a brief overview of the eukaryote tree of life, we show how understanding the endocytic machinery in a select, but diverse, array of organisms provides insights into endocytic system origins and predicts the likely configuration in the last eukaryotic common ancestor (LECA). Next, we consider three examples in which a comparative approach yielded insight into the function of modern cellular systems. First, using ESCRT-0 as an example, we show how comparative cell biology can discover both lineage-specific novelties (ESCRT-0) as well as previously ignored ancient proteins (Tom1), likely of both evolutionary and functional importance. Second, we highlight the power of comparative cell biology for discovery of previously ignored but potentially ancient complexes (AP5). Finally, using examples from ciliates and trypanosomes, we show that not all organisms possess canonical endocytic pathways, but instead likely evolved lineage-specific mechanisms. Drawing from these case studies, we conclude that a comparative approach is a powerful strategy for advancing knowledge about the general mechanisms and functions of endocytic systems.