Full text release has been delayed at the author’s request until August 20, 2015.

Degree

Master of Science (MS), Bowling Green State University, Biological Sciences, 2012.

Abstract

The export of mRNA from the nucleus is a central step in the cellular response to exogenous signals. To complete such tasks in eukaryotic cells, mRNAs need to form complexes with transport cofactors and export from the nucleus to the cytoplasm through the nuclear pore complexes (NPCs) embedded in nuclear envelope. However, the transport kinetics, the 3D spatial pathways and the selective mechanism for mRNAs exporting through the NPCs remain poorly understood. By labeling firefly luciferase mRNA with fluorescent proteins in living cells, and employing an innovative single-point edge-excitation sub-diffraction (SPEED) microscopy technique recently developed in our lab, we captured the real-time export events of single mRNA molecules through the NPCs with a spatiotemporal resolution of 8 nm and 2 ms. We found that approximately one third of mRNA complexes successfully exported from the nucleus to the cytoplasm after interacting with the NPC by approximately 12 ms. However, the other approximately two thirds of mRNA-protein complexes are hindered at the narrowest central channel of the NPC. Finally,in a 3D view, mRNA complexes primarily paved their passageways through the periphery around a rarely occupied central axial conduit on the nucleoplasmic side and in the central channel of the NPC, then dissociated on the cytoplasmic side of the NPC, and finally passively diffused into the cytoplasm.

Subject Headings

Molecular Biology

Keywords

In vivo; three-dimension; mRNA; nuclear export

Committee / Advisors

Weidong Yang (Advisor)
Paul Morris (Committee Member)
Vipaporn Phuntumart (Committee Member)

Pages

57p.

Document number: bgsu1353608190
Permalink: http://rave.ohiolink.edu/etdc/view?acc_num=bgsu1353608190