TY  - JOUR
AU  - Dharan, Raviv
AU  - Shemesh, Asaf
AU  - Millgram, Abigail
AU  - Zalk, Ran
AU  - Frank, Gabriel A.
AU  - Levi-Kalisman, Yael
AU  - Ringel, Israel
AU  - Raviv, Uri
TI  - Hierarchical Assembly Pathways of Spermine-Induced Tubulin Conical-Spiral Architectures
JO  - ACS nano
VL  - 15
IS  - 5
SN  - 1936-0851
CY  - Washington, DC
PB  - Soc.
M1  - PUBDB-2021-04858
SP  - 8836 - 8847
PY  - 2021
AB  - Tubulin, an essential cytoskeletal protein, assembles into various morphologies by interacting with an array of cellular factors. One of these factors is the endogenous polyamine spermine, which may promote and stabilize tubulin assemblies. Nevertheless, the assembled structures and their formation pathways are poorly known. Here we show that spermine induced the in vitro assembly of tubulin into several hierarchical architectures based on a tubulin conical-spiral subunit. Using solution X-ray scattering and cryo-TEM, we found that with progressive increase of spermine concentration tubulin dimers assembled into conical-frustum-spirals of increasing length, containing up to three helical turns. The subunits with three helical turns were then assembled into tubules through base-to-top packing and formed antiparallel bundles of tubulin conical-spiral tubules in a distorted hexagonal symmetry. Further increase of the spermine concentration led to inverted tubulin tubules assembled in hexagonal bundles. Time-resolved experiments revealed that tubulin assemblies formed at higher spermine concentrations assembled from intermediates, similar to those formed at low spermine concentrations. These results are distinct from the classical transition between twisted ribbons, helical, and tubular assemblies, and provide insight into the versatile morphologies that tubulin can form. Furthermore, they may contribute to our understanding of the interactions that control the composition and construction of protein-based biomaterials.
LB  - PUB:(DE-HGF)16
C6  - pmid:33900736
UR  - <Go to ISI:>//WOS:000656994100081
DO  - DOI:10.1021/acsnano.1c01374
UR  - https://bib-pubdb1.desy.de/record/472135
ER  -