Microtubule Assembly from Single Flared Protofilaments-Forget the Cozy Corner?

Journal Article (Journal Article;Review)

A paradigm shift for models of MT assembly is suggested by a recent cryo-electron microscopy study of microtubules (MTs). Previous assembly models have been based on the two-dimensional lattice of the MT wall, where incoming subunits can add with longitudinal and lateral bonds. The new study of McIntosh et al. concludes that the growing ends of MTs separate into flared single protofilaments. This means that incoming subunits must add onto the end of single protofilaments, forming only a longitudinal bond. How can growth of single-stranded protofilaments exhibit cooperative assembly with a critical concentration? An answer is suggested by FtsZ, the bacterial tubulin homolog, which assembles into single-stranded protofilaments. Cooperative assembly of FtsZ is thought to be based on conformational changes that switch the longitudinal bond from low to high affinity when the subunit is incorporated in a protofilament. This novel mechanism may also apply to tubulin assembly and could be the primary mechanism for assembly onto single flared protofilaments.

Full Text

Duke Authors

Cited Authors

  • Erickson, HP

Published Date

  • June 18, 2019

Published In

Volume / Issue

  • 116 / 12

Start / End Page

  • 2240 - 2245

PubMed ID

  • 31122668

Pubmed Central ID

  • PMC6588822

Electronic International Standard Serial Number (EISSN)

  • 1542-0086

Digital Object Identifier (DOI)

  • 10.1016/j.bpj.2019.05.005


  • eng

Conference Location

  • United States