ESCRT Machinery Mediates Cytokinetic Abscission in the Unicellular Red Alga Cyanidioschyzon merolae

Frontiers in Cell and Developmental Biology

Osami Misumi²  Haruko Kuroiwa³  Tsuneyoshi Kuroiwa³  Yuuta Imoto⁵  Nobuko Sumiya⁶  Takayuki Fujiwara⁷  Shin-ya Miyagishima⁷  Fumi Yagisawa⁸  Kan Tanaka^1,10  Yuki Kobayashi^1,10  Soichi Nakamura^1,11  Tokiaki Takemura^1,12 

[1] 0Department of Biological Science and Chemistry, Faculty of Science, Yamaguchi University, Yamaguchi, Japan;1Graduate School of Sciences and Technology for Innovation, Yamaguchi University, Yamaguchi, Japan;2Department of Chemical and Biological Science, Japan Women’s University, Tokyo, Japan;Center for Research Advancement and Collaboration, University of the Ryukyus, Okinawa, Japan;Department of Cell Biology, Johns Hopkins University School of Medicine, Baltimore, MD, United States;Department of Gene Function and Phenomics, National Institute of Genetics, Shizuoka, Japan;Department of Genetics, The Graduate University for Advanced Studies, Shizuoka, Japan;Graduate School of Engineering and Science, University of the Ryukyus, Okinawa, Japan;JST-Mirai Program, Japan Science and Technology Agency, Saitama, Japan;Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology, Yokohama, Japan;Laboratory of Cell and Functional Biology, Faculty of Science, University of the Ryukyus, Okinawa, Japan;School of Life Sciences and Technology, Tokyo Institute of Technology, Yokohama, Japan;

关键词: ESCRT;    cytokinesis;    cytokinetic abscission;    red alga;    Cyanidioschyzon merolae;   

DOI  :  10.3389/fcell.2020.00169

来源: DOAJ

【 摘 要 】

In many eukaryotes, cytokinesis proceeds in two successive steps: first, ingression of the cleavage furrow and second, abscission of the intercellular bridge. In animal cells, the actomyosin contractile ring is involved in the first step, while the endosomal sorting complex required for transport (ESCRT), which participates in various membrane fusion/fission events, mediates the second step. Intriguingly, in archaea, ESCRT is involved in cytokinesis, raising the hypothesis that the function of ESCRT in eukaryotic cytokinesis descended from the archaeal ancestor. In eukaryotes other than in animals, the roles of ESCRT in cytokinesis are poorly understood. To explore the primordial core mechanisms for eukaryotic cytokinesis, we investigated ESCRT functions in the unicellular red alga Cyanidioschyzon merolae that diverged early in eukaryotic evolution. C. merolae provides an excellent experimental system. The cell has a simple organelle composition. The genome (16.5 Mb, 5335 genes) has been completely sequenced, transformation methods are established, and the cell cycle is synchronized by a light and dark cycle. Similar to animal and fungal cells, C. merolae cells divide by furrowing at the division site followed by abscission of the intercellular bridge. However, they lack an actomyosin contractile ring. The proteins that comprise ESCRT-I–IV, the four subcomplexes of ESCRT, are partially conserved in C. merolae. Immunofluorescence of native or tagged proteins localized the homologs of the five ESCRT-III components [charged multivesicular body protein (CHMP) 1, 2, and 4–6], apoptosis-linked gene-2-interacting protein X (ALIX), the ESCRT-III adapter, and the main ESCRT-IV player vacuolar protein sorting (VPS) 4, to the intercellular bridge. In addition, ALIX was enriched around the cleavage furrow early in cytokinesis. When the ESCRT function was perturbed by expressing dominant-negative VPS4, cells with an elongated intercellular bridge accumulated—a phenotype resulting from abscission failure. Our results show that ESCRT mediates cytokinetic abscission in C. merolae. The fact that ESCRT plays a role in cytokinesis in archaea, animals, and early diverged alga C. merolae supports the hypothesis that the function of ESCRT in cytokinesis descended from archaea to a common ancestor of eukaryotes.

【 授权许可】

Unknown