title: Protein aggregation behavior regulates cyclin transcript localization and cell-cycle control.
abstract: Little is known about the active positioning of transcripts outside of embryogenesis or highly polarized cells. We show here that a specific G1 cyclin transcript is highly clustered in the cytoplasm of large multinucleate cells. This heterogeneous cyclin transcript localization results from aggregation of an RNA-binding protein, and deletion of a polyglutamine stretch in this protein results in random transcript localization. These multinucleate cells are remarkable in that nuclei cycle asynchronously despite sharing a common cytoplasm. Notably, randomization of cyclin transcript localization significantly diminishes nucleus-to-nucleus differences in the number of mRNAs and synchronizes cell-cycle timing. Thus, nonrandom cyclin transcript localization is important for cell-cycle timing control and arises due to polyQ-dependent behavior of an RNA-binding protein. There is a widespread association between polyQ expansions and RNA-binding motifs, suggesting that this is a broadly exploited mechanism to produce spatially variable transcripts and heterogeneous cell behaviors. PAPERCLIP:
authors.affiliation: Department of Biological Sciences, Dartmouth College, Hanover, NH 03755, USA.
authors.forename: Changhwan
authors.initials: C
authors.lastname: Lee
authors.forename: Huaiying
authors.initials: H
authors.lastname: Zhang
authors.forename: Amy E
authors.initials: AE
authors.lastname: Baker
authors.forename: Patricia
authors.initials: P
authors.lastname: Occhipinti
authors.forename: Mark E
authors.initials: ME
authors.lastname: Borsuk
authors.forename: Amy S
authors.initials: AS
authors.lastname: Gladfelter
mesh_terms: D016764:Cell Polarity / Q000235:genetics; D016213:Cyclins / Q000235:genetics* / Q000378:metabolism*; D003593:Cytoplasm / Q000378:metabolism; D055169:Eremothecium / Q000166:cytology / Q000235:genetics* / Q000378:metabolism*; D005656:Fungal Proteins / Q000235:genetics / Q000378:metabolism; D016193:G1 Phase / Q000235:genetics; D015966:Gene Expression Regulation, Fungal / Q000502:physiology; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D016601:RNA-Binding Proteins / Q000235:genetics / Q000378:metabolism; D015533:Transcriptional Activation / Q000502:physiology*
chemical_list: D016213:Cyclins; D005656:Fungal Proteins; D012333:RNA, Messenger; D016601:RNA-Binding Proteins