The rise and fall of the phragmoplast microtubule array

Curr Opin Plant Biol. 2013 Dec;16(6):757-63. doi: 10.1016/j.pbi.2013.10.008. Epub 2013 Oct 27.

Abstract

The cytokinetic apparatus, the phragmoplast, contains a bipolar microtubule (MT) framework that has the MT plus ends concentrated at or near the division site. This anti-parallel MT array provides tracks for the transport of Golgi-derived vesicles toward the plus ends so that materials enclosed are subsequently deposited at the division site. Here we will discuss a proposed model of the centrifugal expansion of the phragmoplast that takes place concomitantly with the assembly of the cell plate, the ultimate product of vesicle fusion. The expansion is a result of continuous MT assembly at the phragmoplast periphery while the MTs toward the center of the phragmoplast are disassembled. These events are the result of MT-dependent MT polymerization, bundling of anti-parallel MTs coming from opposite sides of the division plane that occurs selectively at the phragmoplast periphery, positioning of the plus ends of cross-linked MTs at or near the division site by establishing a minimal MT-overlapping zone, and debundling of anti-parallel MTs that is triggered by phosphorylation of MT-associated proteins. The debundled MTs are disassembled at last by factors including the MT severing enzyme katanin.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.
  • Review

MeSH terms

  • Actin Cytoskeleton / metabolism*
  • Cytokinesis*
  • Microtubule-Associated Proteins / metabolism
  • Microtubules / metabolism*
  • Models, Biological*
  • Plant Cells / metabolism
  • Plant Proteins / metabolism
  • Transport Vesicles / metabolism

Substances

  • Microtubule-Associated Proteins
  • Plant Proteins