RT Journal Article
SR Electronic
T1 The AAA-ATPase MIDASIN 1 Functions in Ribosome Biogenesis and Is Essential for Embryo and Root Development
JF Plant Physiology
JO Plant Physiol.
FD American Society of Plant Biologists
SP pp.01225.2018
DO 10.1104/pp.18.01225
A1 Li, Peng-Cheng
A1 Li, Ke
A1 Wang, Juan
A1 Zhao, Chuan-Zhi
A1 Zhao, Shu-Zhen
A1 Hou, Lei
A1 Xia, Han
A1 Ma, Chang-Le
A1 Wang, Xing-Jun
YR 2019
UL http://www.plantphysiol.org/content/early/2019/02/12/pp.18.01225.abstract
AB Ribosome biogenesis is an orchestrated process that relies on many assembly factors. The AAA-ATPase Midasin 1 (Mdn1) functions as a ribosome assembly factor in yeast (Saccharomyces cerevisiae), but the roles of MDN1 in Arabidopsis thaliana are poorly understood. Here, we showed that the Arabidopsis null mutant of MDN1 is embryo-lethal. Using the weak mutant mdn1-1, which maintains viability, we found that MDN1 is critical for the regular pattern of auxin maxima in the globular embryo and functions in root meristem maintenance. By detecting the subcellular distribution of ribosome proteins, we noted that mdn1-1 impairs nuclear export of the pre-60S ribosomal particle. The processing of pre-rRNAs, including 35S, 27SB, and 20S, is also affected in this mutant. MDN1 physically interacts with PESCADILLO 2 (PES2), an essential assembly factor of the 60S ribosome, and the observed mislocalization of PES2 in mdn1-1 further implied that MDN1 plays an indispensable role in 60S ribosome biogenesis. Therefore, the observed hypersensitivity of mdn1-1 to a eukaryotic translation inhibitor and high-sugar conditions might be associated with the defect in ribosome biogenesis. Overall, this work establishes a role of Arabidopsis MDN1 in ribosome biogenesis, which agrees with its roles in embryogenesis and root development.