Skip to Main Content
 

Global Search Box

 
 
 
 

Files

File List


osu1218557154.pdf (11.28 MB)

ETD Abstract Container

Abstract Header

Investigations of the Functions of gamma-Tubulin in Cell Cycle Regulation in Aspergillus nidulans

Nayak, Tania
http://rave.ohiolink.edu/etdc/view?acc_num=osu1218557154

Abstract Details

2008, Doctor of Philosophy, Ohio State University, Molecular Genetics.
Published data have revealed that γ-tubulin has essential, but incompletely understood functions in addition to its established role in microtubule nucleation. Our lab has isolated several conditional γ-tubulin alleles in which γ-tubulin localization is normal, microtubules are abundant and mitotic spindle assembly is not inhibited, but growth is strongly inhibited at restrictive temperatures. Additionally, there were defects in the coordination of late mitotic events (Prigozhina et al., 2004), indicating that γ-tubulin plays a role in the regulation of mitosis. Most mitotic regulatory proteins localize at the spindle pole body during mitosis, as does γ-tubulin, and it is possible that interactions between γ-tubulin and mitotic regulatory proteins are important for coordinating the events of mitosis. One focus of my research has, consequently, been to study the distribution of mitotic regulatory proteins in vivo by fusing them to green fluorescent protein. In order to facilitate GFP tagging, I have generated a strain in which the nkuA (A. nidulans homolog of Ku70) gene is deleted. We have found that this deletion, along with the use of heterologous markers from A. fumigatus, increases the correct gene targeting frequency to >90% (Nayak et al., 2006). Using this system, I have made GFP fusions of many mitotic regulatory proteins and studied their distribution over time by time-lapse live cell imaging in control cells and in cells carrying a γ-tubulin mutant, mipAD159. Three critical mitotic regulatory proteins that are mislocalized in mipAD159: Cyclin B, Cdk1 and MspA. Studies on cyclin B localization in mipAD159 indicate that the mitotic defects of γ-tubulin are at least partially caused by misregulation of an important mitotic regulator, the APC/C. In particular, γ-tubulin plays an essential role in the inactivation of the APC/C at the end of mitosis or in G1. I have determined that this role of γ-tubulin in APC/C inactivation is independent of its role in microtubule nucleation. In addition, I have also characterized the septation initiation network in A. nidulans. This has revealed novel functions of some genes and may be useful in understanding septum initiation, timing and positioning in coenocytic fungi like A. nidulans.
Berl Oakley, PhD (Advisor)
Stephen Osmani, PhD (Committee Member)
Harold Fisk, PhD (Committee Member)
Hay-Oak Park, PhD (Committee Member)
236 p.
Cellular Biology; Genetics; Molecular Biology
&947; -tubulin; APC/C; cyclin B; cell cycle; mitotic exit; spindle pole body

Recommended Citations

Citations

  • Nayak, T. (2008). Investigations of the Functions of gamma-Tubulin in Cell Cycle Regulation in Aspergillus nidulans [Doctoral dissertation, Ohio State University]. OhioLINK Electronic Theses and Dissertations Center. http://rave.ohiolink.edu/etdc/view?acc_num=osu1218557154

    APA Style (7th edition)

  • Nayak, Tania. Investigations of the Functions of gamma-Tubulin in Cell Cycle Regulation in Aspergillus nidulans. 2008. Ohio State University, Doctoral dissertation. OhioLINK Electronic Theses and Dissertations Center, http://rave.ohiolink.edu/etdc/view?acc_num=osu1218557154.

    MLA Style (8th edition)

  • Nayak, Tania. "Investigations of the Functions of gamma-Tubulin in Cell Cycle Regulation in Aspergillus nidulans." Doctoral dissertation, Ohio State University, 2008. http://rave.ohiolink.edu/etdc/view?acc_num=osu1218557154

    Chicago Manual of Style (17th edition)

osu1218557154
1,070
© 2008, all rights reserved.
This open access ETD is published by The Ohio State University and OhioLINK.