Microtubule minus-end aster organization is driven by processive HSET-tubulin clusters.
Nat Commun
; 9(1): 2659, 2018 07 09.
Article
em En
| MEDLINE
| ID: mdl-29985404
ABSTRACT
Higher-order structures of the microtubule (MT) cytoskeleton are comprised of two architectures bundles and asters. Although both architectures are critical for cellular function, the molecular pathways that drive aster formation are poorly understood. Here, we study aster formation by human minus-end-directed kinesin-14 (HSET/KIFC1). We show that HSET is incapable of forming asters from preformed, nongrowing MTs, but rapidly forms MT asters in the presence of soluble (non-MT) tubulin. HSET binds soluble (non-MT) tubulin via its N-terminal tail domain to form heterogeneous HSET-tubulin clusters containing multiple motors. Cluster formation induces motor processivity and rescues the formation of asters from nongrowing MTs. We then show that excess soluble (non-MT) tubulin stimulates aster formation in HeLa cells overexpressing HSET during mitosis. We propose a model where HSET can toggle between MT bundle and aster formation in a manner governed by the availability of soluble (non-MT) tubulin.
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Tubulina (Proteína)
/
Cinesinas
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Proteínas Motores Moleculares
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Microtúbulos
Limite:
Animals
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Humans
Idioma:
En
Ano de publicação:
2018
Tipo de documento:
Article