TY - JOUR
T1 - Ribosome binding protein GCN1 regulates the cell cycle and cell proliferation and is essential for the embryonic development of mice
AU - Yamazaki, Hiromi
AU - Kasai, Shuya
AU - Mimura, Junsei
AU - Ye, Peng
AU - Inose-Maruyama, Atsushi
AU - Tanji, Kunikazu
AU - Wakabayashi, Koichi
AU - Mizuno, Seiya
AU - Sugiyama, Fumihiro
AU - Takahashi, Satoru
AU - Sato, Tsubasa
AU - Ozaki, Taku
AU - Cavener, Douglas R.
AU - Yamamoto, Masayuki
AU - Itoh, Ken
N1 - Funding Information:
This work was supported by grants from the Japan Society for the Promotion of Science (JSPS) (KAKENHI 26111010 and 25293064 to K.I. and 26860178 and 17K08616 to H.Y.), funds from the Naito Foundation and the Karoji Memorial Fund for Medical Research. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. We thank Drs. Masanobu Morita and Fumiki Katsuoka for critical advice. We also thank Siori Osanai, Fumiko Tsukidate, Yuko Tsushima, Michiko Nakata, Ayano Ono, Shun Igarashi and Dr. Ryo Ito for technical assistance and laboratory members for useful discussions.
Publisher Copyright:
© 2020 Yamazaki et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
PY - 2020/4
Y1 - 2020/4
N2 - Amino acids exert many biological functions, serving as allosteric regulators and neurotransmitters, as constituents in proteins and as nutrients. GCN2-mediated phosphorylation of eukaryotic initiation factor 2 alpha (elF2α) restores homeostasis in response to amino acid starvation (AAS) through the inhibition of the general translation and upregulation of amino acid biosynthetic enzymes and transporters by activating the translation of Gcn4 and ATF4 in yeast and mammals, respectively. GCN1 is a GCN2-binding protein that possesses an RWD binding domain (RWDBD) in its C-terminus. In yeast, Gcn1 is essential for Gcn2 activation by AAS; however, the roles of GCN1 in mammals need to be established. Here, we revealed a novel role of GCN1 that does not depend on AAS by generating two Gcn1 mutant mouse lines: Gcn1-knockout mice (Gcn1 KO mice (Gcn1-/-)) and RWDBD-deleted mutant mice (Gcn1Δ RWDBD mice). Both mutant mice showed growth retardation, which was not observed in the Gcn2 KO mice, such that the Gcn1 KO mice died at the intermediate stage of embryonic development because of severe growth retardation, while the Gcn1Δ RWDBD embryos showed mild growth retardation and died soon after birth, most likely due to respiratory failure. Extension of pregnancy by 24 h through the administration of progesterone to the pregnant mothers rescued the expression of differentiation markers in the lungs and prevented lethality of the Gcn1Δ RWDBD pups, indicating that perinatal lethality of the Gcn1Δ RWDBD embryos was due to simple growth retardation. Similar to the yeast Gcn2/ Gcn1 system, AAS- or UV irradiation-induced elF2α phosphorylation was diminished in the Gcn1Δ RWDBD mouse embryonic fibroblasts (MEFs), suggesting that GCN1 RWDBD is responsible for GCN2 activity. In addition, we found reduced cell proliferation and G2/M arrest accompanying a decrease in Cdk1 and Cyclin B1 in the Gcn1Δ RWDBD MEFs. Our results demonstrated, for the first time, that GCN1 is essential for both GCN2-dependent stress response and GCN2-independent cell cycle regulation.
AB - Amino acids exert many biological functions, serving as allosteric regulators and neurotransmitters, as constituents in proteins and as nutrients. GCN2-mediated phosphorylation of eukaryotic initiation factor 2 alpha (elF2α) restores homeostasis in response to amino acid starvation (AAS) through the inhibition of the general translation and upregulation of amino acid biosynthetic enzymes and transporters by activating the translation of Gcn4 and ATF4 in yeast and mammals, respectively. GCN1 is a GCN2-binding protein that possesses an RWD binding domain (RWDBD) in its C-terminus. In yeast, Gcn1 is essential for Gcn2 activation by AAS; however, the roles of GCN1 in mammals need to be established. Here, we revealed a novel role of GCN1 that does not depend on AAS by generating two Gcn1 mutant mouse lines: Gcn1-knockout mice (Gcn1 KO mice (Gcn1-/-)) and RWDBD-deleted mutant mice (Gcn1Δ RWDBD mice). Both mutant mice showed growth retardation, which was not observed in the Gcn2 KO mice, such that the Gcn1 KO mice died at the intermediate stage of embryonic development because of severe growth retardation, while the Gcn1Δ RWDBD embryos showed mild growth retardation and died soon after birth, most likely due to respiratory failure. Extension of pregnancy by 24 h through the administration of progesterone to the pregnant mothers rescued the expression of differentiation markers in the lungs and prevented lethality of the Gcn1Δ RWDBD pups, indicating that perinatal lethality of the Gcn1Δ RWDBD embryos was due to simple growth retardation. Similar to the yeast Gcn2/ Gcn1 system, AAS- or UV irradiation-induced elF2α phosphorylation was diminished in the Gcn1Δ RWDBD mouse embryonic fibroblasts (MEFs), suggesting that GCN1 RWDBD is responsible for GCN2 activity. In addition, we found reduced cell proliferation and G2/M arrest accompanying a decrease in Cdk1 and Cyclin B1 in the Gcn1Δ RWDBD MEFs. Our results demonstrated, for the first time, that GCN1 is essential for both GCN2-dependent stress response and GCN2-independent cell cycle regulation.
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U2 - 10.1371/journal.pgen.1008693
DO - 10.1371/journal.pgen.1008693
M3 - Article
C2 - 32324833
AN - SCOPUS:85083948891
VL - 16
JO - PLoS Genetics
JF - PLoS Genetics
SN - 1553-7390
IS - 4
M1 - e1008693
ER -