title: Proline-rich transcript in brain protein induces stress granule formation.
abstract: The repression of translation in environmentally stressed eukaryotic cells causes the sequestration of translation initiation factors and the 40S ribosomal subunit into discrete cytoplasmic foci called stress granules (SGs). Most components of the preinitiation complex, such as eIF3, eIF4A, eIF4E, eIF4G, and poly(A)-binding protein, congregate into SGs under stress conditions. However, the molecular basis of translation factor sequestration into SGs has not been clearly elucidated. Here, we report that proline-rich transcript in brain (PRTB) protein interacts with eIF4G and participates in SG formation. PRTB was recruited to SG under sodium arsenite and heat stress conditions. When overexpressed, PRTB inhibited global translation and formed SGs containing TIA-1, eIF4G, and eIF3. Knockdown of PRTB reduced the SG formation induced by sodium arsenite. These results suggest that PRTB not only is a component of SG formed by cellular stresses but also plays an important role in SG formation via an interaction with the scaffold protein eIF4G, which is associated with many translation factors and mRNAs.
authors.affiliation: PBC, Department of Life Science, Pohang University of Science and Technology, San31, Hyoja-Dong, Pohang 790-784, Republic of Korea.
authors.forename: Jung-Eun
authors.initials: JE
authors.lastname: Kim
authors.forename: Incheol
authors.initials: I
authors.lastname: Ryu
authors.forename: Woo Jae
authors.initials: WJ
authors.lastname: Kim
authors.forename: Ok-Kyu
authors.initials: OK
authors.lastname: Song
authors.forename: Jeongeun
authors.initials: J
authors.lastname: Ryu
authors.forename: Mi Yi
authors.initials: MY
authors.lastname: Kwon
authors.forename: Joon Hyun
authors.initials: JH
authors.lastname: Kim
authors.forename: Sung Key
authors.initials: SK
authors.lastname: Jang
mesh_terms: D000818:Animals; D002460:Cell Line; D002522:Chlorocebus aethiops; D003594:Cytoplasmic Granules / Q000378:metabolism*; D039603:Eukaryotic Initiation Factor-4G / Q000235:genetics / Q000378:metabolism; D005786:Gene Expression Regulation; D006801:Humans; D010455:Peptides / Q000235:genetics / Q000378:metabolism*; D011485:Protein Binding; D014176:Protein Biosynthesis; D021381:Protein Transport; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D034741:RNA, Small Interfering / Q000235:genetics / Q000378:metabolism
chemical_list: D039603:Eukaryotic Initiation Factor-4G; D010455:Peptides; D012333:RNA, Messenger; D034741:RNA, Small Interfering; C120430:prtb peptide