A new factor in non-centrosomal microtubule assembly

Chromosome segregation requires the formation of K-fibres, microtubule bundles that attach sister kinetochores to spindle poles. Most K-fibre microtubules originate around the chromosomes through a non-centrosomal RanGTP-dependent pathway and become oriented with the plus ends attached to the kinetochore and the minus ends focused at the spindle poles. The capture and stabilization of microtubule plus ends at the kinetochore has been extensively studied but very little is known on how their minus-end dynamics are controlled.

Here Isabelle Verno’s lab at the CRG shows that MCRS1 is a RanGTP-regulated factor essential for non-centrosomal microtubule assembly. MCRS1 localizes to the minus ends of chromosomal microtubules and K-fibres, where it protects them from depolymerization. Their data reveal the existence of a mechanism that stabilizes the minus ends of chromosomal microtubules and K-fibres, and is essential for the assembly of a functional bipolar spindle.

Reference:
Meunier S, Vernos I. K-fibre minus ends are stabilized by a RanGTP-dependent mechanism essential for functional spindle assembly. Nat Cell Biol. 2011 Nov 13;

Advertisements

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s