Merck

Kinesin-5 mediated chromosome congression in insect spindles.

Cellular and molecular bioengineering (2018-03-20)
Emily Tubman, Yungui He, Thomas S Hays, David J Odde
ABSTRACT

The microtubule motor protein kinesin-5 is well known to establish the bipolar spindle by outward sliding of antiparallel interpolar microtubules. In yeast, kinesin-5 also facilitates chromosome alignment "congression" at the spindle equator by preferentially depolymerizing long kinetochore microtubules (kMTs). The motor protein kinesin-8 has also been linked to chromosome congression. Therefore, we sought to determine whether kinesin-5 or kinesin-8 facilitates chromosome congression in insect spindles. RNAi of the kinesin-5 Klp61F and kinesin-8 Klp67A were performed separately in RNAi of Klp61F with a weak Klp61F knockdown resulted in longer kMTs and less congressed kinetochores compared to control over a range of conditions, consistent with kinesin-5 length-dependent depolymerase activity. RNAi of the kinesin-8 Klp67A revealed that kMTs relative to the spindle lengths were not longer compared to control, but rather that the spindles were longer, indicating that Klp67A acts preferentially as a length-dependent depolymerase on interpolar microtubules without significantly affecting kMT length and chromosome congression. This study demonstrates that in addition to establishing the bipolar spindle, kinesin-5 regulates kMT length to facilitate chromosome congression in insect spindles. It expands on previous yeast studies, and it expands the role of kinesin-5 to include kMT assembly regulation in eukaryotic mitosis.

MATERIALS
Product Number
Brand
Product Description

Sigma-Aldrich
Shields and Sang M3 Insect Medium, With L-glutamine and potassium bicarbonate., liquid, sterile-filtered, suitable for insect cell culture
Sigma-Aldrich
Schneider′s Insect Medium, With L-glutamine and sodium bicarbonate, liquid, sterile-filtered, suitable for insect cell culture
Sigma-Aldrich
Insect Medium Supplement (10×), liquid, sterile-filtered, BioReagent, suitable for insect cell culture
Sigma-Aldrich
Anti-α-Tubulin antibody, Mouse monoclonal, clone DM1A, purified from hybridoma cell culture