Mythical origins of the actin cytoskeleton.

Affiliation

Akıl C(1), Kitaoku Y(2), Tran LT(2), Liebl D(3), Choe H(4), Muengsaen D(5), Suginta W(5), Schulte A(5), Robinson RC(6).
Author information:
(1)Institute of Molecular and Cell Biology, A∗STAR
(Agency for Science, Technology and Research), Biopolis, 138673, Singapore; Tokyo Institute of Technology, Earth-Life Science Institute
(ELSI), Tokyo 152-8551, Japan.
(2)Research Institute for Interdisciplinary Science
(RIIS), Okayama University, Okayama 700-8530, Japan.
(3)A∗STAR Microscopy Platform, Research Support Center, A∗STAR, Biopolis 138673, Singapore.
(4)Department of Physiology, University of Ulsan College of Medicine, Asan Medical Center, Seoul, 05505, South Korea.
(5)School of Biomolecular Science and Engineering
(BSE), Vidyasirimedhi Institute of Science and Technology
(VISTEC), Rayong 21210, Thailand.
(6)Institute of Molecular and Cell Biology, A∗STAR
(Agency for Science, Technology and Research), Biopolis, 138673, Singapore; Research Institute for Interdisciplinary Science
(RIIS), Okayama University, Okayama 700-8530, Japan; School of Biomolecular Science and Engineering
(BSE), Vidyasirimedhi Institute of Science and Technology
(VISTEC), Rayong 21210, Thailand. Electronic address: [Email]

Abstract

The origin of the eukaryotic cell is one of the greatest mysteries in modern biology. Eukaryotic-wide specific biological processes arose in the lost ancestors of eukaryotes. These distinctive features, such as the actin cytoskeleton, define what it is to be a eukaryote. Recent sequencing, characterization, and isolation of Asgard archaea have opened an intriguing window into the pre-eukaryotic cell. Firstly, sequencing of anaerobic sediments identified a group of uncultured organisms, Asgard archaea, which contain genes with homology to eukaryotic signature genes. Secondly, characterization of the products of these genes at the protein level demonstrated that Asgard archaea have related biological processes to eukaryotes. Finally, the isolation of an Asgard archaeon has produced a model organism in which the morphological consequences of the eukaryotic-like processes can be studied. Here, we consider the consequences for the Asgard actin cytoskeleton and for the evolution of a regulated actin system in the archaea-to-eukaryotic transition.