title: Both G3BP1 and G3BP2 contribute to stress granule formation.
abstract: Upon exposure to various environmental stresses such as arsenite, hypoxia, and heat shock, cells inhibit their translation and apoptosis and then repair stress-induced alterations, such as DNA damage and the accumulation of misfolded proteins. These types of stresses induce the formation of cytoplasmic RNA granules called stress granules (SGs). SGs are storage sites for the many mRNAs released from disassembled polysomes under these stress conditions and are essential for the selective translation of stress-inducible genes. Ras-GTPase-activating protein SH3 domain-binding protein 1 (G3BP1) is a component of SGs that initiates the assembly of SGs by forming a multimer. In this study, we examined the role of G3BP2, a close relative of G3BP1, in SG formation. Although single knockdown of either G3BP1 or G3BP2 in 293T cells partially reduced the number of SG-positive cells induced by arsenite, the knockdowns of both genes significantly reduced the number. G3BP2 formed a homo-multimer and a hetero-multimer with G3BP1. Moreover, like G3BP1, the overexpression of G3BP2 induced SGs even without stress stimuli. Collectively, these results suggest that both G3BP1 and G3BP2 play a role in the formation of SGs in various human cells and thereby recovery from these cellular stresses.
authors.affiliation: Division of Virology, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan.
authors.forename: Hideaki
authors.initials: H
authors.lastname: Matsuki
authors.forename: Masahiko
authors.initials: M
authors.lastname: Takahashi
authors.forename: Masaya
authors.initials: M
authors.lastname: Higuchi
authors.forename: Grace N
authors.initials: GN
authors.lastname: Makokha
authors.forename: Masayasu
authors.initials: M
authors.lastname: Oie
authors.forename: Masahiro
authors.initials: M
authors.lastname: Fujii
mesh_terms: D048868:Adaptor Proteins, Signal Transducing; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism*; D003594:Cytoplasmic Granules / Q000378:metabolism*; D004265:DNA Helicases; D015870:Gene Expression; D055785:Gene Knockdown Techniques; D057809:HEK293 Cells; D006367:HeLa Cells; D006801:Humans; D039102:Poly(A)-Binding Proteins / Q000378:metabolism; D000075223:Poly-ADP-Ribose Binding Proteins; D011485:Protein Binding; D020365:RNA Helicases; D000067776:RNA Recognition Motif Proteins; D016601:RNA-Binding Proteins; D013312:Stress, Physiological; D043222:Ubiquitin Thiolesterase / Q000378:metabolism
chemical_list: D048868:Adaptor Proteins, Signal Transducing; D002352:Carrier Proteins; C574606:G3BP2 protein, human; D039102:Poly(A)-Binding Proteins; D000075223:Poly-ADP-Ribose Binding Proteins; D000067776:RNA Recognition Motif Proteins; D016601:RNA-Binding Proteins; C431363:USP10 protein, human; D043222:Ubiquitin Thiolesterase; D004265:DNA Helicases; C116070:G3BP1 protein, human; D020365:RNA Helicases