Microtubules: Kar3 Eats up the Track
نویسنده
چکیده
Molecular motors are quintessential bio-machines found throughout phylogeny. A new application of in vitro assays highlights an unexpected dual functionality for the motor domain of the microtubule-based kinesin-14 type motor protein from budding yeast.
منابع مشابه
Kar3 interaction with Cik1 alters motor structure and function.
Kar3, a kinesin-14 motor of Saccharomyces cerevisiae required for mitosis and karyogamy, reportedly interacts with Cik1, a nonmotor protein, via its central, predicted coiled coil. Despite this, neither Kar3 nor Cik1 homodimers have been observed in vivo. Here we show that Kar3 is a dimer in vitro by analytical ultracentrifugation. The motor domains appear as paired particles by rotary-shadow e...
متن کاملThe Cik1/Kar3 motor complex is required for the proper kinetochore-microtubule interaction after stressful DNA replication.
In budding yeast Saccharomyces cerevisiae, kinetochores are attached by microtubules during most of the cell cycle, but the duplication of centromeric DNA disassembles kinetochores, which results in a brief dissociation of chromosomes from microtubules. Kinetochore assembly is delayed in the presence of hydroxyurea, a DNA synthesis inhibitor, presumably due to the longer time required for centr...
متن کاملVik1 Modulates Microtubule-Kar3 Interactions through a Motor Domain that Lacks an Active Site
Conventional kinesin and class V and VI myosins coordinate the mechanochemical cycles of their motor domains for processive movement of cargo along microtubules or actin filaments. It is widely accepted that this coordination is achieved by allosteric communication or mechanical strain between the motor domains, which controls the nucleotide state and interaction with microtubules or actin. How...
متن کاملLoss of Function of the Cik1/Kar3 Motor Complex Results in Chromosomes with Syntelic Attachment That Are Sensed by the Tension Checkpoint
The attachment of sister kinetochores by microtubules emanating from opposite spindle poles establishes chromosome bipolar attachment, which generates tension on chromosomes and is essential for sister-chromatid segregation. Syntelic attachment occurs when both sister kinetochores are attached by microtubules from the same spindle pole and this attachment is unable to generate tension on chromo...
متن کاملKinesin Kar3 and Vik1 Go Head to Head
The yeast kinesin motor protein Kar3 forms a heterodimer with a nonmotor protein Vik1. A study in this issue by Allingham et al. (2007) reveals that Vik1 unexpectedly has a structure similar to a kinesin motor domain yet lacks a nucleotide-binding site and is thus catalytically inactive. However, this does not hinder movement of the heterodimer because other features of the remarkably divergent...
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ورودعنوان ژورنال:
- Current Biology
دوره 15 شماره
صفحات -
تاریخ انتشار 2005