Asymmetric distribution of nuclear pore complexes and the cytoplasmic localization of beta2-tubulin mRNA in Chlamydomonas reinhardtii.
Although it is generally accepted that nuclear architecture is an important determinant of nuclear activity, it is not clear whether cytoplasmic events, such as transcript localization and cell polarity, are affected by this architecture. Characterization of the nuclear architecture of the single-cell alga Chlamydomonas reinhardtii revealed a polarized nucleus, with nuclear pore complexes preferentially concentrated at the posterior side of the nucleus. Nuclear asymmetry was greatly exaggerated during the upregulation of genes encoding flagellar proteins, when nuclear pore complexes (NPCs) were observed to hyperpolarize to the posterior side of the nucleus while heterochromatin polarized to the anterior side. Interestingly, prior to deflagellation, the beta2-tubulin gene was preferentially located in the posterior region of the nucleus, and following deflagellation, beta2-tubulin transcripts accumulated posteriorly in polysome-rich cytoplasmic regions adjacent to the highest concentration of NPCs, suggesting a connection between nuclear architecture and cytoplasmic transcript localization.
Colón-Ramos
Daniel A
DA
Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC 27710, USA.
Salisbury
Jeffrey L
JL
Sanders
Mark A
MA
Shenoy
Shailesh M
SM
Singer
Robert H
RH
García-Blanco
Mariano A
MA
D000818:Animals; D002467:Cell Nucleus / Q000648:ultrastructure; D016764:Cell Polarity; D016825:Chlamydomonas reinhardtii / Q000235:genetics* / Q000378:metabolism / Q000502:physiology; D003593:Cytoplasm / Q000737:chemistry / Q000378:metabolism* / Q000648:ultrastructure; D005407:Flagella / Q000502:physiology; D006570:Heterochromatin / Q000378:metabolism / Q000648:ultrastructure; D009685:Nuclear Envelope / Q000648:ultrastructure; D022022:Nuclear Pore / Q000378:metabolism* / Q000648:ultrastructure; D012333:RNA, Messenger / Q000235:genetics* / Q000378:metabolism; D014404:Tubulin / Q000235:genetics* / Q000648:ultrastructure
D006570:Heterochromatin; D012333:RNA, Messenger; D014404:Tubulin