Investigation of a Novel Interaction Between Microtubules and the Yeast Kinesin-5 Cin8
Başlık:
Investigation of a Novel Interaction Between Microtubules and the Yeast Kinesin-5 Cin8
Yazar:
Bell, Kayla, author.
ISBN:
9780438100572
Yazar Ek Girişi:
Fiziksel Tanımlama:
1 electronic resource (216 pages)
Genel Not:
Source: Dissertation Abstracts International, Volume: 79-11(E), Section: B.
Advisors: Jared C. Cochran Committee members: Stephen D. Bell; Ke Hu; Sidney L. Shaw.
Özet:
Kinesin-5 motors play central roles in establishing and maintaining the mitotic spindle during cell division. Cin8 is a homotetrameric kinesin-5 in Saccharomyces cerevisiae that moves bidirectionally along microtubules, switching directionality based on ionic strength, motor coupling and antiparallel microtubule binding. It plays critical roles in establishing spindle bipolarity during prophase and in separating the spindle poles during anaphase. The mechanism by which it accomplishes these divergent roles is still poorly understood. However it is believed that Cin8's bidirectionality plays a role in partitioning Cin8 between the minus-end of the microtubules during spindle formation and toward the plus-ends of the microtubules and the spindle midzone during spindle separation. In this study I used kinetic, thermodynamic, and structural methodologies to show that Cin8 binds multiple motor domains per tubulin dimer in the microtubule lattice, binding to both the canonical kinesin binding site and a novel noncanonical binding site on the microtubule. Cin8 also forms dimers of motors when bound to the canonical and non-canonical sites, showing defined oligomerization that I have shown is not the result of random aggregation. Furthermore, I cloned, expressed, purified and characterized chimeric motor domains with swapped loop-8 regions for Eg5, Cin8 and Kip1 to show that noncanonical binding of Cin8 to the microtubule is mediated by Cin8's large loop-8 region in an ATP-dependent manner. I propose that while super-stoichiometric binding is not essential for bidirectional motility, it still plays a role in regulating directionality. I hypothesize that dimerization of Cin8 motors through motor domain or loop-8 interactions enable Cin8 clustering at minus ends of microtubules during prophase. This clustering may play an important role in preventing Cin8 from escaping the spindle midzone during anaphase by slowing down Cin8 motors at the edge of the midzone long enough for polymerizing microtubule ends to recapture them. Additionally, I hypothesize that Cin8 binding to the noncanonical site via loop-8 interaction with the microtubule causing steric hindrance and motor crowding, both of which affect bidirectional switching in yeast kinesin-5 motors.
Notlar:
School code: 0093
Konu Başlığı:
Tüzel Kişi Ek Girişi:
Mevcut:*
Yer Numarası | Demirbaş Numarası | Shelf Location | Lokasyon / Statüsü / İade Tarihi |
---|---|---|---|
XX(695079.1) | 695079-1001 | Proquest E-Tez Koleksiyonu | Arıyor... |
On Order
Liste seç
Bunu varsayılan liste yap.
Öğeler başarıyla eklendi
Öğeler eklenirken hata oldu. Lütfen tekrar deneyiniz.
:
Select An Item
Data usage warning: You will receive one text message for each title you selected.
Standard text messaging rates apply.